1554.6-2012 Welding of Stainless Steels for Structural Purposes

AS/NZS 1554.6:2012

AS/NZS 1554.6:2012

Australian/New Zealand Standard™

Accessed by BUREAU VERITAS AUSTRALIA PTY LTD on 27 Mar 2013 (Document currency not guaranteed when printed)

Structural steel welding Part 6: Welding stainless steels for structural purposes

AS/NZS 1554.6:2012 This Joint Australian/New Zealand Standard was prepared by Joint Technical Committee WD-003, Welding of Structures. It was approved on behalf of the Council of Standards Australia on 16 February 2012 and on behalf of the Council of Standards New Zealand on 9 May 2012. This Standard was published on 31 May 2012.


The following are represented on Committee WD-003: Australasian Corrosion Association Australian Chamber of Commerce and Industry Australian Industry Group Australian Steel Institute AUSTROADS Bureau of Steel Manufacturers of Australia Engineers Australia New Zealand Heavy Engineering Research Association New Zealand Non-Destructive Testing Association Steel Reinforcement Institute of Australia The University of Sydney Welding Technology Institute of Australia

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This Standard was issued in draft form for comment as DR AS/NZS 1554.6.

AS/NZS 1554.6:2012

Australian/New Zealand Standard™


Structural steel welding Part 6: Welding stainless steels for structural purposes

Originated as AS/NZS 1554.6:1994. Second edition 2012.

COPYRIGHT © Standards Australia Limited/Standards New Zealand All rights are reserved. No part of this work may be reproduced or copied in any form or by any means, electronic or mechanical, including photocopying, without the written permission of the publisher, unless otherwise permitted under the Copyright Act 1968 (Australia) or the Copyright Act 1994 (New Zealand). Jointly published by SAI Global Limited under licence from Standards Australia Limited, GPO Box 476, Sydney, NSW 2001 and by Standards New Zealand, Private Bag 2439, Wellington 6140

ISBN 978 1 74342 116 1

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PREFACE This Standard was prepared by the Joint Standards Australia/Standards New Zealand Committee WD-003, Welding of Structures, to supersede AS/NZS 1554.6:1994. The objective of this Standard is to provide rules for the welding of a wide range of stainless steel fabrications (other than pressure vessels and pressure piping), and it applies to statically and dynamically loaded welds. The objective of this revision is to substantially update the Standard to reflect changes in structural welding since the publication of the original edition in 1994. As this is a major revision, changes from the previous edition are not indicated in this Preface. This Standard requires that weld preparations, welding consumables and welding procedures be qualified before commencement of welding. Prequalified joint preparations, welding consumables and welding procedures are also given in this Standard.


Strength capacity of welds is not covered in this Standard and designers are referred to relevant design codes or specifications for this purpose. Statements expressed in mandatory terms in notes to tables are deemed to be requirements of this Standard. The terms ‘normative’ and ‘informative’ have been used in this Standard to define the application of the appendix to which they apply. A ‘normative’ appendix is an integral part of a Standard, whereas an ‘informative’ appendix is only for information and guidance.

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CONTENTS Page


SECTION 1 SCOPE AND GENERAL 1.1 SCOPE ......................................................................................................................... 5 1.2 EXCLUSIONS............................................................................................................. 5 1.3 INNOVATION ............................................................................................................ 6 1.4 NORMATIVE REFERENCES .................................................................................... 6 1.5 DEFINITIONS............................................................................................................. 6 1.6 WELD CATEGORIES AND SURFACE FINISHES................................................... 6 1.7 MANAGEMENT OF QUALITY ................................................................................. 7 1.8 HEAT TREATMENT .................................................................................................. 7 1.9 SAFETY ...................................................................................................................... 8 SECTION 2 MATERIALS OF CONSTRUCTION 2.1 GENERAL ................................................................................................................... 9 2.2 PARENT MATERIAL ................................................................................................. 9 2.3 BACKING MATERIAL .............................................................................................. 9 2.4 WELDING CONSUMABLES ..................................................................................... 9 SECTION 3 DETAILS OF WELDED CONNECTIONS 3.1 GENERAL ................................................................................................................. 11 3.2 BUTT WELDS .......................................................................................................... 11 3.3 FILLET WELDS ....................................................................................................... 14 3.4 COMPOUND WELDS .............................................................................................. 16 3.5 SEAL WELDS ........................................................................................................... 18 3.6 PLUG WELDS .......................................................................................................... 18 3.7 SLOT WELDS ........................................................................................................... 18 3.8 COMBINING STEEL SECTIONS ............................................................................ 18 SECTION 4 QUALIFICATION OF PROCEDURES AND PERSONNEL 4.1 QUALIFICATION OF WELDING PROCEDURE.................................................... 20 4.2 METHOD OF QUALIFICATION OF WELDING PROCEDURE ............................ 22 4.3 PREQUALIFIED WELDING PROCEDURES .......................................................... 22 4.4 PORTABILITY OF QUALIFIED WELDING PROCEDURES ................................ 23 4.5 PREQUALIFIED JOINT PREPARATIONS ............................................................. 23 4.6 QUALIFICATION OF WELDING CONSUMABLES .............................................. 30 4.7 QUALIFICATION OF WELDING PROCEDURE BY TESTING ............................ 34 4.8 EXTENSION OF QUALIFICATION ........................................................................ 38 4.9 COMBINATION OF PROCESSES ........................................................................... 39 4.10 RECORDS OF TESTS .............................................................................................. 41 4.11 REQUALIFICATION OF WELDING PROCEDURES ............................................ 41 4.12 QUALIFICATION OF WELDING PERSONNEL .................................................... 45 SECTION 5 WORKMANSHIP 5.1 GENERAL ................................................................................................................. 50 5.2 TRANSPORT, STORAGE AND HANDLING ......................................................... 50 5.3 MARKING ................................................................................................................ 50 5.4 CUTTING .................................................................................................................. 50 5.5 FABRICATION ......................................................................................................... 51 5.6 PREPARATION OF EDGES FOR WELDING ......................................................... 51 5.7 ASSEMBLY .............................................................................................................. 51

AS/NZS 1554.6:2012


5.8 5.9 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 5.21

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BACKING MATERIAL ............................................................................................ 52 ARC ENERGY INPUT .............................................................................................. 53 PREHEATING AND INTERRUN CONTROL ......................................................... 53 WELDING UNDER ADVERSE WEATHER CONDITIONS ................................... 53 TACK WELDS .......................................................................................................... 54 INTERRUN CLEANING .......................................................................................... 55 WELD DEPTH-TO-WIDTH RATIO......................................................................... 55 CONTROL OF DISTORTION AND RESIDUAL STRESS ...................................... 55 BACKGOUGING AND REPAIR OF DEFECTS IN WELDS................................... 56 TEMPORARY ATTACHMENTS ............................................................................. 57 ARC STRIKES .......................................................................................................... 57 CLEANING OF FINISHED WELDS ........................................................................ 57 DRESSING OF BUTT WELDS ................................................................................ 58 LEAK TEST WATER ............................................................................................... 58

SECTION 6 QUALITY OF WELDS 6.1 CATEGORIES OF WELDS ...................................................................................... 59 6.2 SURFACE FINISHES OF WELDS ........................................................................... 59 6.3 METHODS OF INSPECTION AND PERMISSIBLE LEVELS OF IMPERFECTIONS .................................................................................................... 62 6.4 RADIOGRAPHY ...................................................................................................... 68 6.5 ULTRASONIC EXAMINATION .............................................................................. 70 6.6 LIQUID PENETRANT EXAMINATION ................................................................. 70 6.7 WELD DEFECTS ...................................................................................................... 71 6.8 REPORTING ............................................................................................................. 71 SECTION 7 INSPECTION 7.1 GENERAL ................................................................................................................. 72 7.2 QUALIFICATIONS OF INSPECTORS .................................................................... 72 7.3 VISUAL INSPECTION OF WORK .......................................................................... 72 7.4 NON-DESTRUCTIVE EXAMINATION OTHER THAN VISUAL ......................... 73 APPENDICES A NORMATIVE REFERENCES .................................................................................. 74 B SELECTION OF WELD CATEGORY AND SURFACE FINISH ............................ 77 C TYPICAL FORMS FOR WELDING PROCEDURES .............................................. 80 D WELDED JOINT AND PROCESS IDENTIFICATION ........................................... 83 E CORROSION TESTING ......................................................................................... 109 F FERRITE CONTENT OF WELDS .......................................................................... 110 G MATTERS FOR RESOLUTION ............................................................................. 113 H WELDING DISSIMILAR METALS ....................................................................... 114 BIBLIOGRAPHY ................................................................................................................... 118

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STANDARDS AUSTRALIA/STANDARDS NEW ZEALAND Australian/New Zealand Standard Structural steel welding Part 6: Welding stainless steels for structural purposes

S E C T I O N

1

S C O P E

A N D

G E N E R A L

1.1 SCOPE


This Standard specifies requirements for the welding of stainless steel structures made up of combinations of stainless steel plate, sheet, sections, including hollow sections and built-up sections, or castings and forgings, by the following processes: (a)

Manual metal arc welding (MMAW).

(b)

Submerged arc welding (SAW).

(c)

Gas metal arc welding (GMAW).

(d)

Gas tungsten arc welding (GTAW).

(e)

Flux cored arc welding (FCAW).

(f)

Plasma arc welding (PAW).

The Standard applies to the welding of steelwork in structures complying with appropriate Standards. Where welded joints are governed by dynamic loading conditions, the Standard applies to those welded joints that comply with the fatigue provisions of the relevant application Standards. The Standard prescribes materials of construction, weld preparations and weld qualities, surface finish, qualification of welding procedures and welding personnel, and fabrication and inspection requirements for welds related to all stainless steel fabrication including aesthetic, hygienic or other non-structural applications. NOTE: GMAW includes waveform controlled welding such as "synergic", "programmable", and "microprocessor controlled" processes' e.g. pulsed spray transfer, controlled short circuit transfer. 1.2 EXCLUSIONS The Standard does not cover the selection of grades to suit the corrosion requirements, although an informative appendix is included. The Standard does not cover the design of welded connections or permissible stresses in welds, nor the production, rectification or repair of castings. The Standard does not apply to the welding of pressure vessels and pressure piping. NOTE: For further guidance on welding of stainless steel, refer to AWS D1.6, WTIA Technical Note 13, WRC Bulletin 519 and ASSDA Reference Manual. For guidance on selection to suit corrosion requirements, refer to AS/NZS 4673.

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1.3 INNOVATION Any alternative stainless steel materials, welding processes, consumables, methods of construction or testing that give equivalent results to those specified, but do not comply with the specific requirements of this Standard or are not mentioned in it, are not necessarily prohibited. The joint Australian/New Zealand Standards Committee WD-003, Welding of Structures, can act in an advisory capacity concerning equivalent suitability, but specific approval remains the prerogative of the inspecting authority. 1.4 NORMATIVE REFERENCES Documents referenced for normative purposes are listed in Appendix A. NOTE: Documents referenced for informative purposes are listed in the Bibliography. 1.5 DEFINITIONS For the purpose of this Standard, the definitions given in AS 1101.3 and AS 2812 and those below apply. Accessed by BUREAU VERITAS AUSTRALIA PTY LTD on 27 Mar 2013 (Document currency not guaranteed when printed)

1.5.1 Fabricator The person or organization responsible for the welding of the structure during fabrication or erection. 1.5.2 Inspecting authority The authority having statutory powers to control the design and erection of buildings or structures. NOTE: Where the structure is not subject to statutory jurisdiction, the principal is deemed to be the inspecting authority. 1.5.3 Inspector A person employed by or acceptable to the inspecting authority or principal for the purpose of inspecting welding in accordance with this Standard. 1.5.4 May Indicates the existence of an option. 1.5.5 Principal The purchaser or owner of the structure being fabricated or erected or a nominated representative. NOTE: The nominated representative should be suitably qualified to deal with the technical issues of this Standard. 1.5.6 Shall Indicates a requirement. 1.5.7 Should Indicates a recommendation. 1.6 WELD CATEGORIES AND SURFACE FINISHES NOTE: For guidance on the selection of weld categories and surface finishes, see Appendix B.

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1.6.1 Weld categories The Standard provides six categories of welds based on the type of application. These involve the selection of one of three levels of internal imperfections combined with one of three classes of surface imperfections (see Section 6). 1.6.2 Surface finishes The Standard provides three grades of surface finish based on the type of application (see Section 6). 1.6.3 Welds subject to dynamic loading For welds subject to levels of dynamic loading where AS 4100 and NZS 3404.1 require detail category 112 or lower, weld imperfections shall meet the requirements of category 1B in accordance with Section 6 of this Standard.


Where detail categories greater than 112 are applicable, weld imperfections shall meet the requirements of category FA in accordance with Section 6, and transition of thickness or width for butt welds shall comply with Clause 3.2.5. NOTE: Category FA may be suitable for austenitic stainless steel structures designed in accordance with the guidelines of AS/NZS 4673 Appendix F. 1.7 MANAGEMENT OF QUALITY 1.7.1 Quality management Fabricators shall ensure that all welding and related activities prescribed within Clause 1.7.2 and this Standard are managed under a suitable quality management system. Such a system should generally comply with the requirements of AS/NZS ISO 3834 and its parts, particularly where fabrication activities require the approval of the principal or inspecting authority, or where the fabrication of large, complex or critical structures is being undertaken. 1.7.2 Basic welding requirements The basis of this Standard is that a weld shall— (a)

be made in accordance with a qualified welding procedure;

(b)

be carried out by a welder suitably qualified to carry out such a procedure;

(c)

be carried out under the supervision of a welding supervisor who is employed by or contracted to the fabricator; and

(d)

comply with the appropriate requirements of this Standard.

For certain conditions prescribed herein, the welding procedure is deemed to be prequalified and may not require full qualification testing (see Clause 4.3 and Table 4.7.1). 1.8 HEAT TREATMENT Postweld heat treatment (PWHT) is not normally required or necessary for austenitic, ferritic or ferritic-austenitic (duplex) stainless steels. Martensitic stainless steels generally require pre and post weld heat treatment. Ferritics generally cannot and should not be heat treated. Heat treatment of these grades is not covered by this Standard. Where required, heat treatment should be carried out in accordance with the manufacturer’s instructions for the grade specified. It is important to note that heat treatments used for carbon steels can be highly detrimental to both the corrosion and mechanical properties of stainless steels. NOTE: Expert advice should be sought where dissimilar metal joints are to be heattreated. Refer to AS 4458 for information on PWHT. COPYRIGHT

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1.9 SAFETY 1.9.1 Welding safety Welding shall be carried out in accordance with the relevant requirements of AS 1470, AS 1674.1, AS 1674.2, AS/NZS 1336, AS/NZS 1337, AS/NZS 1338.1 and AS 2865. 1.9.2 Welding equipment Welding plant and equipment shall comply with all the relevant sections of appropriate regulations, and the relevant requirements of AS 1966.1, AS 1966.2, AS 2799, AS/NZS 1995 and AS 60974.1. 1.9.3 Pickling and passivation Both pickling and passivation use acids that can be damaging to health and the environment. For Australia, requirements of the relevant hazardous substances legislation promulgated by the regulatory authorities shall be followed. For New Zealand, requirements of the Environmental Risk Management Authority (ERMA) shall be followed. NOTE: Pickling treatments also passivate the surface during washing.


1.9.4 Other hazards The fabricator shall identify and manage any other risks and hazards from welding that are not covered by Clauses 1.9.1 and 1.9.2. Due consideration shall be given to the control and dispersal of emitted fumes including when welding through surface coatings, and the safe handling and disposal of surface treatment chemicals including pickling and passivation pastes. NOTES: 1 Guidance on the management of risk is given in AS/NZS ISO 31000. 2 Further guidance on safety precautions is given in WTIA Technical Notes 7 and 22, and the ASSDA Reference Manual.

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S E C T I O N

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M A T E R I A L S

AS/NZS 1554.6:2012

O F

C O N S T R U C T I O N

2.1 GENERAL The grades of materials and welding consumables given in this Standard shall be traceable to the manufacturer. 2.2 PARENT MATERIAL


The parent material to be welded shall be of any one of the following groups: (a)

Austenitic stainless steels.

(b)

Ferritic stainless steels.

(c)

Martensitic stainless steels.

(d)

Duplex (ferritic-austenitic) stainless steels.

The selection of the appropriate alloy grade for any application is the responsibility of the principal. Alternative grades shall only be acceptable with permission of the principal. NOTES: 1 Precipitation hardening grades are not included but may be dealt with under the innovation provisions (see Clause 1.3). 2 For guidance on the welding of dissimilar stainless steel to structural carbon steel joints see Appendix H. 2.3 BACKING MATERIAL Permanently attached backing material shall be of the same grade as the structure unless otherwise agreed with the principal. Where permanent backing is exposed to corrosive media it shall be seal welded to the structure. Temporary backing bars, especially those made of copper, shall contain an appropriate groove and weld parameters shall be modified to avoid copper pick-up in the weld. 2.4 WELDING CONSUMABLES 2.4.1 Electrodes and filler metals Electrodes or filler metals having chemical composition complying with the following Standards are prequalified where they are matched with the steel types in accordance with Table 4.6.1. •

AS/NZS 1167.2;

•

AS/NZS 4854;

•

AS/NZS ISO 14343;

•

AS/NZS ISO 17633;

•

ANSI/AWS A5.4;

•

ANSI/AWS A5.9;

•

ANSI/AWS A5.22.

When requested by the principal (see Appendix G), the fabricator shall provide the manufacturer’s certification that filler metals meet the requirements of the classification of grade and minimum ferrite numbers (FN) for all-weld-metal test. NOTE: For filler metals according to AWS A5.22 and AWS A5.9, certification should indicate a ferrite number for the all-weld-metal of at least 3.0FN. COPYRIGHT

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2.4.2 Care of electrodes and filler metals Electrodes and filler wires shall be stored in a warm dry place adequately protected from any damage that will hinder the intended use and quality of the deposited weld. Where special protection during storage and use is recommended by the manufacturer, electrodes and filler wires they shall be stored and used in accordance with the recommended conditions. Filler wires shall be dry, smooth and free from corrosion or other matter deleterious either to satisfactory operation or to the weld metal. If the electrodes or filler wires are coated, the coating shall be continuous and firmly adherent. Where the manufacturer makes specific recommendations covering conditioning and pretreatment of electrodes prior to use, such recommendations shall be followed. Off cut material shall not be used as filler material. NOTE: WTIA Technical Note 3 contains recommendations for the storage and conditioning of consumables. 2.4.3 Flux


Flux for submerged arc welding shall be kept dry and stored in accordance with the manufacturer’s instructions. Where the manufacturer makes specific recommendations covering conditioning and pretreatment of flux prior to use, such recommendations shall be followed. Where flux is re-used, flux recycling systems shall include suitable sieves and magnetic particle separators and shall be such that the flux remains in a satisfactory condition for re-use. Flux that is fused in the welding process shall not be re-used. NOTE: Flux for submerged arc welding should be selected to prevent loss of chromium or increase of carbon content in the weld. 2.4.4 Shielding, backing or purging gas Gas and gas mixtures used for shielding, backing or purging shall be of a welding grade complying with the requirements of AS 4882 and suitable for the intended application.

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SECTI ON

3 DET AILS OF C O N N E C T I O N S

AS/NZS 1554.6:2012

W E LDED

3.1 GENERAL 3.1.1 Permissible weld types Welded connections may be made by butt, fillet, plug, or slot welds, or by a combination of these. 3.1.2 Drawings


Drawings or other documents which give details of welded connections shall specify the following: (a)

Specification, grade and thickness of parent metal.

(b)

Location, type, size, and effective length of all welds.

(c)

Whether welds are to be made in the shop or at the site.

(d)

Weld category and surface finish.

(e)

Surface treatment.

(f)

Details of non-standard welds.

(g)

Where seal welds are required, details of such welds.

(h)

Type and extent of inspection, including any special inspection requirements.

(i)

Any special requirements that could affect welding operations.

3.2 BUTT WELDS 3.2.1 Size of weld The size of a complete penetration butt weld shall be the thickness of the thinner part. The size of a complete penetration butt weld for a T-joint or corner joint butt weld shall be the thickness of the part that butts against the face of the other part. The size of an incomplete penetration butt weld shall be the minimum depth to which the weld extends from its face into the joint, exclusive of reinforcement. Where the joint contains two welds, the size shall be the combined depths. 3.2.2 Design throat thickness 3.2.2.1 Complete penetration butt weld For stress calculations, the design throat thickness of a complete penetration butt weld shall be the thickness of the thinner part. 3.2.2.2 Incomplete penetration butt weld For stress calculations, the design throat thickness of an incomplete penetration butt weld shall be as follows: (a)

Prequalified incomplete penetration butt weld except as otherwise provided in Item (c) below, as shown in Table D2, Appendix D.

(b)

Non-prequalified incomplete penetration butt weld except as provided in Item (c) below— (i)

where θ < 60°: D − 3 mm; or

(ii)

where θ ≥ 60°: D. COPYRIGHT

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where D = depth of preparation θ

= angle of preparation.

(c)

For an incomplete penetration butt weld made by a fully automatic arc welding process, provided that it can be demonstrated by means of a macro test on a production weld that the required penetration has been achieved, an increase in the design throat thickness up to the depth of penetration shall be allowed. Where such penetration is achieved, the size of the weld may be correspondingly reduced. NOTE: Incomplete penetration butt welds may not be suitable for some corrosion applications.

3.2.3 Effective length The effective length of the butt weld shall be the length of a continuous full-size weld. 3.2.4 Effective area The effective area of a butt weld shall be the product of the effective length and the design throat thickness. Accessed by BUREAU VERITAS AUSTRALIA PTY LTD on 27 Mar 2013 (Document currency not guaranteed when printed)

3.2.5 Transition of thickness or width Butt-welded joints between axially aligned parts of different thickness or unequal width that are subject to tension or to fatigue loads shall have a smooth transition between the surfaces or the edges. The transition shall be made by chamfering the thicker part or by sloping the weld surfaces or by any combination of these as shown in Figure 3.2.5. The transition slope between the parts subject to tensile stress shall not be steeper than 1:1. However, fatigue or other design considerations may require a lesser slope than this or a curved transition between the parts. For category FA welds, the transition slope between the parts shall not exceed 4:1. Buttwelded T-joints may have a small fillet weld superimposed on each welded face not t exceeding the lesser of 6 mm or thinner . 3 Larger fillet welds are not permitted unless a compound joint (see Clause 3.4) has been specified by the designer.

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4 5˚ m a x. C h a mfe r b efo r e we l di n g

4 5˚ m a x. C h a mfe r b efo r e we l di n g

4 5˚ m a x. Centre-line alignment ( p a r ti c u l a r l y a p p l i c a b l e to we b p l ate s)

O f f s e t a l i g n m e nt ( p a r ti c u l a r l y a p p l i c a b l e to f l a n g e p l ate s)

( i ) Tr a n s i ti o n by c h a mfe r i n g thi c ke r p a r t

4 5˚ m a x.

4 5˚ m a x.

4 5˚ m a x.

4 5˚ m a x. R e m ove a f te r we l d i n g

4 5˚ m a x.

4 5˚ m a x.

( ii ) Tr a n s i ti o n by s l o p i n g we l d s u r fa c e


R e m ove af te r we l di n g

( iii ) Tr a n s i ti o n by s l o p i n g we l d s u r fa c e a n d c h a mfe r i n g

(a) Tr a n s i ti o n of b u t t j o i nt s i n p a r t s of u n e q u a l thi c k n e s s

4 5˚ m a x. Butt joint W i d t h of w i d e r p l a te W i d t h of n a r r owe r p l a te 4 5˚ m a x. ( b) Tr a n s i ti o n of b u t t j o i nt s i n p a r t s of u n e q u a l wi d th, tr a n s i ti o n by c h a mfe r i n g wi d e r p a r t

S e e D e t a il >135˚ L e s s e r of 5 m m t o r thinner 3

>135˚

NOTES: 1

Transition slopes shall comply with Clause 3.2.5.

2

These diagrams do not prescribe minimum transition slopes as fatigue considerations may require more gradual transitions.

FIGURE 3.2.5 TRANSITION OF THICKNESSES OR WIDTHS FOR BUTT WELDS SUBJECT TO TENSION OR FATIGUE LOADS

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3.3 FILLET WELDS 3.3.1 Size of weld The size of a fillet weld shall be the leg length as defined by AS 2812. The preferred sizes of fillet welds less than 15 mm are 2, 3, 4, 5, 6, 8, 10 and 12 mm. Where there is a root gap, the size shall be given by the lengths of the legs of the inscribed triangle reduced by the amount shown in Table D3. The size of a fillet weld shall satisfy strength or corrosion requirements (or both). 3.3.2 Design throat thickness For stress calculations, the design throat thickness of a fillet weld shall be as shown in Table D3, Appendix D.


For deep penetration welds made by fully automatic arc welding processes, provided that it can be demonstrated by means of a macro test on a production weld that the required penetration has been achieved, an increase in design throat thickness shall be allowed as shown in Figure 3.3.2. Where such penetration is achieved, the size of the weld may be correspondingly reduced.

D1

D2

NOTE: DTT = D1 + 0.85 D2, where DTT is the design throat thickness for deep penetration fillet welds made by a fully automatic process.

FIGURE 3.3.2 DEEP PENETRATION WELD

3.3.3 Effective length The effective length of a fillet weld shall be the overall length of the full-size fillet, including end returns. Where the weld is full size throughout its length, no reduction in effective length shall be made for either the start or crater of the weld. Where the effective length of a fillet weld is less than four times the size of the weld, the size of the weld for design calculation purposes shall be reduced to 25% of the effective length. Any segment of intermittent fillet weld shall have an effective length of not less than 40 mm. 3.3.4 Effective area The effective area of a fillet weld shall be the product of the effective length and the design throat thickness. 3.3.5 Minimum size of fillet welds The minimum size of a fillet weld, including the first run of a multi-run fillet weld, other than a fillet weld used to reinforce a butt weld, shall conform to Table 3.3.5 except that the size of the weld need not exceed the thickness of the thinner part joined (see also Clause 5.3). COPYRIGHT

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TABLE 3.3.5 MINIMUM SIZE (LEG LENGTH) OF FILLET WELDS millimetres Thickness of thickest part (t)

Minimum size of fillet weld

≤3

2t/3*

>3 ≤7

3*

>7 ≤10

4*

>10 ≤15

5

>15

6

* These values may need to be increased to comply with some design standards.

3.3.6 Maximum size of fillet welds along edges


The maximum size of a fillet weld along edges of material shall be— (a)

for material with a thickness of less than 6 mm (see Figure 3.3.6(a)), the thickness of the material;

(b)

for material with thickness of not less than 6 mm (see Figure 3.3.6(b)), the thickness of the material minus 1 mm; or

(c)

for material with a thickness of not less than 6 mm, where the weld is designated on the drawing to be built out to obtain the design throat thickness (see Figure 3.3.6(c)), the thickness of the material.

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t

S

(a) S = t fo r t < 6 m m 1 m m m i n.


t

S

( b) S < t - 1 m m fo r t > 6 m m B u il t o u t h e r e to e n s u r e n o d e f i c i e n cy i n s ize

t

S

(c) S = t fo r a ll thi c k n e s s e s w h e r e e d g e i s b u il t o u t L EG EN D: S = s ize of f ill e t we l d t = th i c k n e s s of p a r t j o i n e d

FIGURE 3.3.6 MAXIMUM SIZE OF FILLET WELDS ALONG EDGES

3.4 COMPOUND WELDS 3.4.1 Description of compound weld A compound weld is a butt-welded T-joint with a fillet weld superimposed on one or both faces. Details of typical compound welds are shown in Figure 3.4.1.

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( b) Fill e t we l d s u p e r i m p o s e d o n s i n g l e b eve l b u t t-we l d e d T- j o i nt wi th a n a d d i ti o n a l f ill e t we l d o n th e r o ot s i d e

(a) Fill e t we l d s u p e r i m p o s e d o n s i n g l e b eve l b u t t-we l d e d T- j o i nt


(c) Fill e t we l d s u p e r i m p o s e d o n s i n g l e J - b u t t-we l d e d T- j o i nt wi th a n a d di ti o n a l f ill e t we l d o n th e r o ot s i d e

(d ) Fill e t we l d s u p e r i m p o s e d o n i n c o m p l e te p e n e t r a ti o n b eve l we l d

FIGURE 3.4.1 COMPOUND WELDS

3.4.2 Design throat thickness (DTT) 3.4.2.1 Complete penetration butt weld For stress calculations, the DTT of compound welds with complete penetration welds in the T-joint shall be the thickness of the part that butts against the face of the other part. 3.4.2.2 Incomplete penetration butt weld For stress calculations, the DTT of compound welds with incomplete penetration welds shall be as shown in Figure 3.4.2.2, where DTT is the shortest distance from the root of the incomplete penetration welds to the face of the fillet welds as determined by the largest inscribed triangle in the total weld cross-section, with a maximum value equal to the thickness of the part that butts against the face of the other part to form the T-joint.

DT T

90˚

DT T

90˚ DT T

90˚

NOTE: The design throat thickness (DTT) of a weld is the minimum distance from the root of a weld to its face, less any reinforcement. The three sketches above illustrate this concept.

FIGURE 3.4.2.2 DESIGN THROAT THICKNESS OF COMPOUND WELDS WITH INCOMPLETE PENETRATION WELDS

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3.5 SEAL WELDS Seal welds shall be made in accordance with a qualified welding procedure. Seal welds shall be single-run fillet or incomplete penetration butt welds as applicable. NOTES: 1 Where seal welding is required, this should be specified clearly on the drawings or other documents (see Clause 3.1.2). 2 Seal welds are frequently used in stainless steel fabrication to seal crevices which may act as sites for corrosion. 3.6 PLUG WELDS The minimum diameter of the hole for a plug weld shall be no less than the thickness of the part containing it plus 8 mm. The maximum diameter shall equal the minimum diameter plus 3 mm or 2.25 times the thickness of the member, whichever is greater. The minimum centre-to-centre spacing of plug welds shall be four times the diameter of the hole.


The effective area of a plug weld shall be the nominal cross-sectional area of the hole in the plane of the faying or contact surface. The depth of the filling of plug welds shall be as follows: Material thickness (t) mm

Depth of filling mm

≤16

t

>16 ≤32

≥16

>32

≥t/2

3.7 SLOT WELDS The length of the slot for a slot weld shall not exceed 10 times the thickness of the part containing it. The width of the slot shall be— (a)

not less than the sum of 8 mm plus the thickness of the part containing the slot; and

(b)

not more than the greater of— (i)

the minimum width plus 3 mm; and

(ii)

2.25 times the thickness of the member.

The ends of the slot shall be semicircular or shall have the corners rounded to a radius not less than the thickness of the part containing it, except those ends which extend to the edge of the part. The minimum spacing of lines of slot welds in a direction transverse to their length shall be four times the width of the slot. The minimum centre-to-centre spacing in a longitudinal direction on any line shall be two times the length of the slot. The effective area of a slot weld shall be as for a fillet weld of the same size and effective length. Where a slot weld is made by completely or partially filling the slot and not made with a fillet weld around the perimeter of the slot, the effective area shall be as for plug welds. 3.8 COMBINING STEEL SECTIONS The size of welds made for the purpose of combining rolled steel sections shall be taken as shown in Figure 3.8 and shall satisfy strength or corrosion requirements, or both. NOTE: Incomplete penetration welds are only allowed where there is no risk of crevice corrosion. COPYRIGHT

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S ize of we l d

(a) H o l l ow s e c ti o n s


S ize of we l d

( b) B e a m s o r c o l u m n s

S ize of we l d S ize of we l d

(c) C h a n n e l s

S ize of we l d

(d ) A n g l e s

FIGURE 3.8 WELDING OF ROLLED SECTIONS TO FORM BUILT-UP MEMBERS

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S E C T I O N 4 Q U A L I F I C A T I O N O F P R O C E D U R E S A N D P E R S O N N E L 4.1 QUALIFICATION OF WELDING PROCEDURE 4.1.1 General The welding procedure (that is the weld preparation, the welding consumables and the welding parameters) shall be qualified before welding of either the structure or the component commences. A welding procedure shall be established and the applicable parameters listed in the welding procedure qualification record PQR, which shall be held as a record and shall be available for examination.


A welding procedure specification shall be developed from the PQR, based on the limits of the essential variables of Clause 4.11, and made available to the welder during fabrication. The welding procedure may be approved on the welding procedure sheets by a representative of the principal, who shall have, as a minimum, the qualification of a welding supervisor in accordance with Clause 4.12.1 or welding inspector (see Clause 7.2). NOTE: Forms suitable as PQR and welding procedure specification (WPS) are shown in Appendix C. 4.1.2 Butt welds For complete penetration and incomplete penetration butt welds, the following also apply: (a)

For welding processes MMAW, SAW, GMAW, GTAW and FCAW, a procedure qualification of a butt weld that has been welded from only the one side on a single-V or a single-U preparation shall qualify for single-sided butt welds in both plate and pipe.

(b)

A procedure qualification for any prequalified butt-welded joint listed in Table D1, D2 or D4, Appendix D, shall qualify all other welding positions listed for that joint and angle of preparation (θ) used without further testing. A change in welding direction between vertical up and vertical down shall require separate qualification.

(c)

A procedure qualification on a single-V butt weld that has been welded from only the one side shall qualify for welding a double-V butt weld and a single-V butt weld that has been welded on both sides.

(d)

A procedure qualification on a single bevel butt weld that has been welded from only the one side shall qualify for welding a double bevel butt weld and a single bevel butt weld that has been welded on both sides.

(e)

A procedure qualification on a single-U butt weld that has been welded from only the one side shall qualify for welding a double-U butt weld and a single-U butt weld that has been welded on both sides.

(f)

A procedure qualification on a single-J butt weld that has been welded from only the one side shall qualify for welding a double-J butt weld and a single-J butt weld that has been welded on both sides.

(g)

A procedure qualification on a double-V butt weld shall also qualify for welding a single-V butt weld that has been welded on both sides.

(h)

A procedure qualification on a double bevel butt weld shall also qualify for welding a single bevel butt weld that has been welded on both sides.

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(i)

A procedure qualification on a double-U butt weld shall also qualify for welding a single-U butt weld that has been welded on both sides.

(j)

A procedure qualification on a double-J butt weld shall also qualify for welding a single-J butt weld that has been welded on both sides.

(k)

Thickness limitations for butt welds shall comply with the following: (i)

For material with a thickness of less than 36 mm, Item (n) of Table 4.11(A) applies.

(ii)

For material with a thickness of not less than 36 mm, no upper limit applies.

(iii) For T-butt joints between members of non-equal thickness, the thickness limitation applicable to the prepared member abutting the non-prepared member shall apply. NOTE: When applying these thickness limitations, an adjustment to the minimum preheat temperature may be required (see Clause 5.10). 4.1.3 Fillet welds


For fillet welds, the following also apply: (a)

The procedure qualification of a fillet weld using processes on either plate or pipe shall qualify for fillet welds on both plate and pipe.

(b)

The procedure qualification of a fillet weld shall be based on the fillet weld size (leg length), not material thicknesses, as follows:

(c)

(i)

For a single-run fillet weld, qualification shall cover the size of the fillet weld used for the qualification test and all single-run fillet welds below the size qualified as permitted within the ranges of the essential variables of Table 4.11(A) for the positions shown in Table 4.1.3.

(ii)

For multi-run fillet welds, qualification shall cover the size of the fillet weld used for qualification and all larger multi-run fillet welds for the positions shown in Table 4.1.3. When applying this qualification for single-run and multi-run fillets, consideration shall be given to the pre heat requirements for combined thicknesses of T1, T2 and T3, and the pre heat requirements for the combined thicknesses shall be shown on the welding procedure specification (WPS) and on the PQR.

A change in welding direction between vertical up and vertical down shall require separate qualification. NOTE: Single-run and multiple-run fillet welds may be qualified on opposite sides of the same test plates. TABLE 4.1.3 PROCEDURE QUALIFICATION FOR FILLET WELDS ON PLATE OR PIPE—POSITIONS QUALIFIED Weld position

Position qualified

1F (flat)

1F only

2F (horizontal)

1F, 2F and 4F (overhead)

3F (vertical)

3F only

4F (overhead)

1F, 2F and 4F

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4.1.4 Qualification of multiple welding positions Where a test piece requires procedure qualification in more than one position, the test piece qualifies the welding procedures for those positions, provided a macro is taken from each position to be qualified. NOTE: This can be achieved by welding a pipe test piece in the 5G or 6G fixed position. 4.2 METHOD OF QUALIFICATION OF WELDING PROCEDURE


A welding procedure shall be qualified by one of the following methods: (a)

A prequalified procedure in accordance with Clause 4.3.

(b)

Production of documentary evidence of relevant prior experience by the fabricator. NOTE: A completed welding procedure sheet such as one of those shown in Appendix C, together with records of any tests carried out as required by the application Standard to which the procedure was qualified constitutes documentary evidence of prior experience.

(c)

Production of a suitable length of test piece of the same joint type, material type, material thickness, surface finish, and edge preparation as the component upon which the procedures are to be applied, and testing it in accordance with Clause 4.7 where the type of joint allows such testing. The test piece may be fabricated as a run-on or run-off piece during production.

(d)

Preparation of a special test piece, such as shown in Figure 4.7.2, which simulates as closely as practicable the weld preparation, material type and direction of rolling, material thickness, edge preparation, surface finish, welding conditions, and conditions of restraint to be used in production, and testing it in accordance with Clause 4.7.

(e)

Destructive testing of a prototype joint, structure, or component.

(f)

A welding procedure qualified by another fabricator, see Clause 4.4.

All welding procedures shall meet the requirements of essential variables and weld categories of AS/NZS 1554.6. 4.3 PREQUALIFIED WELDING PROCEDURES Welding procedures shall be deemed to be prequalified where all the following conditions are satisfied: (a)

The joint preparations are prequalified in accordance with Clause 4.5.

(b)

The consumables are prequalified in accordance with Clause 4.6.

(c)

The workmanship and welding techniques, including the preheat and inter-run temperature requirements and surface finish requirements, comply with this Standard.

(d)

Documentary evidence is available of a satisfactory macro test in accordance with Clause 4.7.4 and Table 4.7.1, including a satisfactory macro or a sketch or photograph, showing the position number, the sequence of runs, the minimum leg length, the throat thickness and the scale of the sketch. NOTE: For the purpose of this requirement, a digital or scanned image is considered to be the equivalent of a photograph.

(e)

Where required by the principal, documentary evidence is available of a satisfactory corrosion test in accordance with Clause 4.7.7.

(f)

Where required by the principal, documentary evidence is available of a satisfactory ferritic content as specified (see Clause 4.7.8).

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In addition, requirements for preheat, PWHT and heat input limitation shall be stipulated where appropriate (see Table 5.10). For ferritic grades, any heat input limitation shall be stipulated. Prequalified welding procedures shall be fully documented. 4.4 PORTABILITY OF QUALIFIED WELDING PROCEDURES A welding procedure qualified by one fabricator shall be valid for use by a second fabricator, provided that— (a)

the original qualification tests were carried out in accordance with this Standard or other acceptable national or international Standards, and were fully documented;

(b)

the second fabricator has adequate equipment and facilities and demonstrates successful welding in welder qualification tests or a macro test using the procedure;

(c)

the application of the welding procedure is acceptable to both fabricators and the principal; and

(d)

the welding procedure identifies the original and second fabricator.


4.5 PREQUALIFIED JOINT PREPARATIONS 4.5.1 General The joint preparations prescribed in Clauses 4.5.2, 4.5.3 and 4.5.4 shall be deemed prequalified provided that the welding processes and consumables used comply with the recommendations of the electrode manufacturer. NOTES: 1 Single sided incomplete penetration butt welds and fillet welds may not be suitable for some corrosion applications due to the presence of the crevice on the reverse side. The approval of the principal should be sought. 2 Super duplexes may require a larger root gap for butt welds than that for other types of stainless steels. The steel manufacturer's welding specifications should be followed. 4.5.2 Prequalified complete penetration butt welds Joint preparations for prequalified complete penetration butt welds conforming to a preparation listed in Table D1, shall be deemed prequalified. Provided that each preparation complies with the requirements of Table D1 for double-V, double bevel, double-U, and double-J welds, preparations of unequal depth shall be deemed prequalified also. NOTE: For additional requirements for hollow sections, see Clause 4.5.5. Complete penetration butt welds that are to be welded from both sides using these prequalified preparations shall have the roots of the weld gouged out by suitable means to sound metal, before welding is started on the second side, unless evidence is produced by macro etching that complete fusion can be obtained without such gouging. 4.5.3 Prequalified incomplete penetration butt welds Joint preparations for prequalified incomplete penetration butt welds that conform to a preparation listed in Table D2, shall be deemed prequalified. Provided that each preparation complies with the requirements of Table D2, for double-V, double bevel, double-U, and double-J, preparations of unequal depth are prequalified also. NOTE: For additional requirements for hollow sections, see Clause 4.5.5.

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4.5.4 Prequalified fillet welds Joint preparations for prequalified fillet welds conforming to a preparation listed in Table D3, shall be deemed prequalified. Welding positions shall comply with AS 3545 (see also Table 4.5.4). NOTES: 1 For additional requirements for fillet welds for hollow sections, see Clause 4.5.5. 2 Single-run and multiple-run fillet welds may be qualified on opposite sides of the same test plates. TABLE 4.5.4 PROCEDURE QUALIFICATION FOR FILLET WELDS ON PLATE OR PIPE, AND SIZE QUALIFIED Number of test welds per procedure

Macro etch samples

Single-run maximum size to be used in qualification

One

Multi-run minimum size to be used in qualification

One


Fillet size

Sizes qualified Material thickness

Fillet size

See Table 4.7.1

Unlimited

Maximum test size single-run and smaller

See Table 4.7.1

Unlimited

Minimum test size multi-run and larger

4.5.5 Additional requirements for welds in hollow section members 4.5.5.1 Complete penetration butt welds Joint preparations for complete penetration butt welds in rolled hollow sections that conform to one of the following shall be deemed prequalified: (a)

Joints welded from both sides and complying with one of the processes specified in Table D1.

(b)

Joints welded from one side and complying with one of the processes specified in Table D4.

Joint preparations for connections butt welded from one side, complying with the details shown in Figure 4.5.5.1(A) for circular and unequal-width rectangular hollow sections and in Figure 4.5.5.1(B) for equal-width rectangular hollow sections, shall be deemed prequalified for all appropriate processes. 4.5.5.2 Fillet welds Joint preparations for fillet welds conforming to Table D3, shall be deemed prequalified for all processes. In addition, the joint preparations shown in Figure 4.5.5.2 for fillet welded connections shall be deemed prequalified for all appropriate processes. NOTE: Joints in Figure 4.5.5.2 form a crevice which may be unsuitable for corrosion applications. Therefore, the approval of the principal should be sought. 4.5.5.3 Combination of fillet and butt welds Joint preparations for combinations of fillet and butt welds, complying with the details shown in Figure 4.5.5.3 for circular and unequal-width rectangular hollow sections and Figure 4.5.5.1(B) for equal-width rectangular hollow sections, shall be deemed prequalified for all processes, provided that the joint preparations for butt welds conform to Table D1, D2 or D4, as appropriate. NOTE: Joints in Figure 4.5.5.3 form a crevice, which may be unsuitable for corrosion applications. The approval of the principal should therefore be sought.

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4.5.5.4 Circular hollow section connections Where a weld connects the end of one circular hollow section member to the surface of another circular hollow section member, the following shall also apply, as appropriate: (a)

Not flattened Where the end of the section is not flattened and the sections intersect at an angle of — (i)

less than 30°, the welding procedure shall be qualified in accordance with Clause 4.2 before welding commences; or

(ii)

not less than 30°, the joint shall comply with the additional requirements in the following table:


Type of Weld

(b)

Usage

Butt throughout, according to Figures 4.5.5.1(A) and (B)

Used in any joint

Fillet throughout, according to Figure 4.5.5.2.

Used only where diameter of smaller members is less than on-third of that of larger member

Combination of butt and fillet with gradual transitions between them, according to Figure 4.5.5.3

Used in any joint

Partially or fully flattened Where the end of a circular hollow section member is partly flattened to a suitable shape, Items (a)(i) and (a)(ii) above shall apply and, for the application of Item (a)(ii), the diameter of the flattened portion of the section shall be measured in a plane perpendicular to the axis of the main section, the plane being taken at the point of intersection of the axis of the branch section with the surface of the main section. The flattening of the section shall be made over the minimum length practicable. The change of shape shall be gradual, with no evidence of splitting or cracking in the flattened portion. Typical flattened circular hollow section joints are shown in Figure 4.5.5.4.

4.5.5.5 End-to-surface connections of rectangular hollow sections For end-to-surface connections of rectangular hollow sections, the following shall also apply, as appropriate: (a)

Angle of intersection not less than 30° Where the end of a rectangular hollow section member is welded to the surface of another rectangular hollow section member of greater width, with the axes of the members intersecting at an angle of not less than 30°, the joint shall comply with one of the following additional requirements: (i)

A butt weld is used throughout.

(ii)

A fillet weld is used throughout.

(iii) A combination of fillet and butt welds is used throughout. (b)

Angle of intersection less than 30° Where the end of a rectangular hollow section member is welded to the surface of another rectangular hollow section member of greater width, with the axes of the members intersecting at an angle of less than 30°, the welding procedure shall be qualified in accordance with Clause 4.2 before welding commences.

(c)

Equal width rectangular hollow sections Where the end of a rectangular hollow section member is welded to the surface of another rectangular hollow section member of equal width, the welding procedure shall be qualified in accordance with Clause 4.2 before welding commences. COPYRIGHT

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Db

Db

90˚ U

X V

Z Y

Dm

N OT E: A ny va l u e of D b / D m i s p e r m i s s i b l e.

(a) B u t t-we l d e d c o n n e c ti o n s t

t

4 5˚ m i n.

G 4 5˚ m i n.


2 m m m a x. t m i n. 2

2 m m m a x. t m i n. 2 S EC T I O N V

G

S EC T I O N U

( b) B u t t-we l d e d r i g ht- a n g l e d c o n n e c ti o n s t t

t 2t m i n. 4 5˚ m i n.

G

G

t m i n.

4 5˚ m i n.

t m i n. 2

2 m m m a x.

2 mm max.

S EC T I O N X

2 m m m a x. t m i n. 2

G

S EC T I O N Y

S EC T I O N Z

(c) B u t t-we l d e d a c u te - a n g l e d c o n n e c ti o n s

NOTES: 1

θ ≥ 30°.

2

The values for width of root gap (G) are given in Table D4, Appendix D.

3

These sections, as drawn, apply to circular hollow sections.

4

Only Sections U, X and Z apply to unequal-width rectangular hollow sections.

5

For Section Y, see Figure 4.5.5.1(B) for equal-width rectangular hollow sections.

6

For rectangular hollow sections, welds should not be started or stopped at corners.

FIGURE 4.5.5.1(A) PREQUALIFIED BUTT WELDS FOR CIRCULAR AND UNEQUALWIDTH RECTANGULAR HOLLOW SECTIONS

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Bb X


Bm

Z Y

G

S ECT I O N Y

NOTES: 1

θ ≥ 30°.

2

The values for width of root gap (G) are given in Table D4.

3

Placing pieces of metal in the root gap to bridge the gap is not permitted.

4

Sections X and Z are the same as Sections X and Z of Figures 4.5.5.1(A) and 4.5.5.2.

5

For unequal-width rectangular hollow sections, see Figure 4.5.5.1(A).

FIGURE 4.5.5.1(B) PREQUALIFIED BUTT WELDS FOR EQUAL-WIDTH RECTANGULAR HOLLOW SECTIONS

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Db X

Z Y

Dm

t Ed g e m ay b e cut back

t

t

1. 5t m i n.

t 2

G G

t m i n.

G t m i n.

t m i n. t m i n.


S EC T I O N X

S EC T I O N Y

S EC T I O N Z

NOTES: 1

θ ≥ 30°.

2

The values for width of root gap (G) are given in Table D4.

3

These sections, as drawn, apply to circular hollow sections.

4

Only sections X and Z apply to unequal-width rectangular hollow sections.

5

For Section Y, see Figure 4.5.5.1(B) (also see Clause 4.5.5.5(c)).

for

equal-width

rectangular

FIGURE 4.5.5.2 PREQUALIFIED FILLET WELDS

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Db Z

X Y

Dm

t Ed g e m ay b e cut back

t 2 t m i n.

t 1. 5t m i n.

G

t m i n.

G 4 5˚ m i n.


G S EC T I O N X

t m i n. S EC T I O N Y

S EC T I O N Z

NOTES: 1

θ ≥ 30°.

2

The values for width of root gap (G) are given in Table D.

3

These sections apply to circular hollow sections.

4

Only Sections X and Z apply to unequal-width rectangular hollow sections.

5

These details may not apply to equal-width rectangular hollow sections (see Clause 4.5.5.5I).

FIGURE 4.5.5.3 PREQUALIFIED COMBINATION OF FILLET AND BUTT WELDS INCLUDING COMPOUND BUTT AND FILLET WELD

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(a) Pa r ti a ll y f l at te n e d m e m b e r

( b) Fu ll y f l at te n e d m e m b e r

FIGURE 4.5.5.4 FLATTENED CIRCULAR HOLLOW SECTION JOINTS

4.6 QUALIFICATION OF WELDING CONSUMABLES 4.6.1 Filler metals Where welding consumables are matched with the steel types in compliance with Table 4.6.1, they shall be deemed prequalified and require no qualification testing. Where a consumable is not prequalified in accordance with Table 4.6.1, it may be qualified in conjunction with a procedure qualification in accordance with Clause 4.7.1. If the weld metal deposited in the test possesses relevant properties specified by the principal, the consumable shall be deemed qualified for that procedure. NOTE: For further guidance on filler metals for dissimilar metal joints refer to AWS D1.6. 4.6.2 Fluxes Submerged arc fluxes complying with the following are deemed prequalified. They shall— (a)

comply with the requirements of flux class 2 or flux class 4 of ISO 14174;

(b)

be specified by the manufacturer as being suitable for the welding of stainless steels; and

(c)

only be used in flux/wire combinations approved by the consumable manufacturer.

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4.6.3 Shielding, backing and purging gases Shielding, backing and purging gases complying with Clause 2.4.4 are deemed prequalified. Shielding gas that contains hydrogen shall not be used for ferritic, martensitic and duplex stainless steels.


Shielding gas that contains nitrogen shall not be used for austenitic stainless steels. NOTES: 1 Shielding, backing or purging gas should protect the weld area until the temperature of the deposited weld metal drops below 250°C. 2 For GMAW, carbon dioxide levels in argon and/or helium based shielding gas should not exceed 5%. 3 Purging is required for external attachment welding. For further information on purging, refer to Clause 6.2.3(g) and 6.2.6.

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Super duplex

S32304/S32101

S31803/S32205

410/420

444

409/410S/430

1.4003

6% Mo

904L

S30815

347

321H

321

317L

317

316Ti

316L

316H

316

310

309

304L

304H

304

To weld to

AS/NZS 1554.6:2012

TABLE 4.6.1 PREQUALIFIED WELDING CONSUMABLES (see Notes)

AUSTENITIC GRADES (11) 308 (9)

304H

308H

308H

304L

308L

308L

308L (9)

309

308H

308H

308H

309

310

310

310

310

310

310

316

308H

308H

308H

316H

310

316H

316H

316H

316H

316L

316H

310

316H

316H

316L

316L

316L

316L

309L

310

316L

316L

316L

316Ti

318

318

318

318

310

318

318

318

318

317

317

317

308L

309L

310

316H

316H

316L

317

317

317L

317L

317L

317L

309L

310

317L

317L

317L

317L

317L

317L

321

347

347

347

347

310

347

347

347

347

347

347

347

321H

347H

347H

347H

347H

310

347H

347H

347H

347H

347H

347H

347H

347H

347

347

347

347

347

310

347

347

347

347

347

347

347

347

S30815

308H

308H

308H

309HT 309HT 309HT 309HT 309HT

309HT

309HT

309HT

309HT 309HT 309HT 309HT

904L

385

385

385

385

385

385

385

385

385

385

385

385

385

385

385

385

6% Mo

625

625

625

625

625

625

625

625

625

625

625

625

625

625

625

625

32

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347

625 (continued)


TABLE 4.6.1 (continued)

317L

321

321H

347

S30815

904L

6% Mo

316L

316L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L (8)

409/ 410S/ 430

309L

309L

309L

309L

309L

309L

309L: 309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

444

316L

316L

316L

316L

316L

316L

316L

316L

316L

316L

316L

316L

316L

316L

316L

309L

309L

309L

309L (6) 316L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

309L

Super duplex

317

316L

S32304/S32101

316Ti

309L

S31803/S32205

316L

410/420

316H

309L

444

316

409/410S/430

310

316L

1.4003

309

316L

304H

316L

304

304L

To weld to 1.4003

FERRITIC GRADES

410/420

309L

309L

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MARTENSITIC GRADES DUPLEX GRADES S31803/ S32205

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

625

2209

2209

2209

2209

2209

S32304/ S32101

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

625

2209

2209

2209

2209

2209 2209(7)

Super duplex

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

2209

625

2209

2209

2209

2209

2209 2209

Nickel base

NiCr-3 NiCr-3 NiCr-3 NiCr-3 NiCr-3 NiCr-3 NiCr-3 NiCr-3

NiCr-3

NiCr-3

NiCr-3

NiCr-3 NiCr-3 NiCr-3 625

625

625

NiCr-3

NiCr-3 NiCr-3 NiCr-3 625

Carbon 309L steel (10, 13)

309L

309L

309L

310

309L

309L

309LMo 309LMo 309LMo 309LMo 309L

309L

309L

309L

309LMo 309LMo 309LMo 309L

309Mo 309L

625

309L 309L

2510 625 309L

AS/NZS 1554.6:2012

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NOTES TO TABLE 4.6.1: 1

The recommended prequalified consumable for welding one grade to itself, i.e. similar metal welding, is given in bold.

2

For dissimilar metals, welding the grade listed at the intersection of the row and column is recommended. Both this grade and the grade in bold on the intersecting row are prequalified, e.g. for welding 316L to 304L, both 308L and 316L are prequalified.

3

For parent metals designations, refer to AISI, UNS or SEW designations, as appropriate. For welding consumables designations, refer to AS/NZS 1167.2, AS 4854.3, AS/NZS ISO 14343, ANSI/AWS A5.4 or ANS/AWS A5.9, as appropriate.

4

Silicon containing designations in accordance with AS/NZS ISO 14343 are also deemed prequalified, where applicable.

5

Also applies to Grades 201, 202, 301 and 302.

6

Grade 316L is not prequalified for these dissimilar joints.

7

Grade 23 7 LN is also prequalified for Lean Duplex (S32304, S32101) joints.

8

Grade 18 8 Mn is also prequalified for 1.4003 joints.

9

316L is also prequalified

10

For other than 18 8 Mn welding dissimilar carbon to stainless steel joints, austenitic filler metals should have at least 10FN in the all-weld-metal.

11

Steel grade 310, 904L and 6% Mo cannot be expected to provide delta ferrite in their welds. Such steels have some tendency to produce solidification cracking. For guidance on avoiding solidification cracking refer to the Appendix F.

12

Use of "L" grade fillers in place of standard or "H" grades can be made so long as high temperature requirements are considered. Low carbon content fillers may not be suitable for high temperature applications.

13

Grade 18 8 Mn is also prequalified for any dissimilar stainless steel to carbon steel joints.

4.7 QUALIFICATION OF WELDING PROCEDURE BY TESTING 4.7.1 Method of qualification Where the welding procedure to be used is not qualified in accordance with Clause 4.2(a), (b) or (e), it shall be qualified by producing a suitable test piece in accordance with either Clause 4.2(c) or Clause 4.2(d), and subjecting the weld in the condition in which it will enter service to the tests specified in Table 4.7.1. Where the weld complies with the relevant test requirements of Clause 4.7, the welding procedure shall be accepted as qualified.

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TABLE 4.7.1 EXTENT OF TESTING REQUIRED ON WELDING PROCEDURE TEST PIECE Tests required (see Notes 1, 2 and 3)*

Weld category

Consumables (see Note 3 and Note 7)*

Prequalified conforming to Table 4.6.1 1A, 1B, 1C and FA

Butt welds (see Note 4)* Preparation

Fillet welds

Tensile (see Clause 4.7.5)

Bend (see Clause 4.7.6) and Note 5)*

Radiography (see Clause 4.7.9)

Macro (see Clause 4.7.4 and Note 6)*

Prequalified conforming to Tables D1 to D4

1

Nil

1 side or 1 face and 1 root (Note 9)

Nil

1

Other preparations

2

Nil

1 side or 1 face and 1 root

100%

2


1

1


100%

1

Other preparations

2

1

2 side or 1 face and root

100%

2


1

Nil

1 side or 1 face and 1 root (Note 9)

Nil

1

Other preparations

1

Nil


Nil

2


1

Nil


Nil

1

Other preparations

1

Nil


Nil

2

Not prequalified

Prequalified conforming to Table 4.6.1

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Macro (see Clause 4.7.4 and Note 6 and Note 8)*

2A, 2B and 2C Not prequalified

* See notes on following page. AS/NZS 1554.6:2012


1

Ferrite content (ferrite numbers) determination, where required by the principal, shall be carried out in accordance with Clause 4.7.8.

2

The hardness test of the plate, weld and heat-affected zone may have an effect upon the performance of the joint in testing and service. Where this is regarded as a factor, it is recommended that a hardness survey of the procedure test joint be made. The details of the tests and the acceptance criteria are the subject of agreement in accordance with Appendix G.

3

Corrosion testing, where required by the principal, shall be carried out in accordance with Clause 4.7.7.

4

Where the weldment is designed for cryogenic application, or if there is a possibility of embrittlement due to welding or other fabrication procedures, a Charpy V test may be specified by the principal. Methods of testing and criteria of acceptance should be agreed between the parties concerned.

5

Bend test is not applicable to martensitic grades.

6

Where two or more macro tests are required, the specimens shall be separated by a distance of at least 100 mm.

7

For austenitic consumables, where required by the principal, electrode manufacturer’s certification shall indicate minimum ferrite numbers for the all-weld-metal according to ISO 8249 or ANSI/AWS A4.2. Alternatively, ferrite numbers may be calculated using the filler metal composition according to the Clause 4.7.8. When radiography is not required to qualify a weld procedure, at the fabricators discretion, a radiograph may be substituted for a macro test. For other than dip transfer in gas metal arc welding, bend tests are not required for austenitic steel grades 304, 304H, 304L, 309, 316, 316H, 316L, 316Ti, 317, 317L, 321, 321H and 347 when heat input and interrun temperature complies with Clause 5.10. 36

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NOTES TO TABLE 4.7.1:

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4.7.2 Preparation of special test piece Where required, a special test piece shall be prepared in accordance with Figure 4.7.2 as appropriate. Under certain circumstances, such as an unusual joint configuration, it may be necessary to prepare two test pieces for different purposes, one, such as that shown in Figure 4.7.2, for testing the weld metal and the other for closely simulating the configuration of the joint for testing the weld penetration. 4.7.3 Dimensions of test pieces The dimensions of the test piece obtained either from a test of the same joint type as the component being welded (see Clause 4.2(c)) or from a run-on, or run-off, piece welded in production, or from the special test piece shown in Figure 4.7.2(a) and 4.7.2(b), shall be sufficient to allow preparation of the required number of test specimens for the tests. 4.7.4 Macro test


The macro test shall be carried out in accordance with AS 2205.5.1. The specimen shall comply with the requirements in Clause 5.6, and Table 6.3.2, as appropriate. Unless it can be proved otherwise for the remainder of the test plate (e.g. by radiographic testing, by ultrasonic testing, by further macro testing), internal imperfections revealed by the test piece shall be assumed to run the full length of the weld and assessed in accordance with Tables 6.3.1(A), 6.3.1(B) and 6.3.2. At the fabricator’s discretion, a radiograph (when not required by Table 4.7.1) may be substituted for a macro test to qualify a weld procedure or welder. 4.7.5 Transverse butt tensile test The transverse butt tensile test shall be carried out in accordance with AS 2205.2.1. The required weld strength shall be greater than or equal to the specified minimum tensile strength of the parent material (or the weaker plate in combination) in the heat treatment condition specified. Where the specimen breaks in the parent metal outside of the weld, the test shall be accepted as meeting the requirements provided that the tensile strength is not less than 95% of the specified minimum for the parent material. The report of results should indicate whether fracture occurred in the weld, at the edge of the weld, or in the parent metal, and whether weld defects are present on the fractured surfaces. 4.7.6 Bend test The bend test shall be carried out in accordance with AS 2205.3.1, using a former having a diameter determined in accordance with Table 4.7.6. For dissimilar metal joints a transverse guided bend test may be replaced by a longitudinal guided bend test according to AS 2205.3.3. On the completion of the test, no crack or other defect in the weld or the heat-affected zone shall be greater than 3 mm, measured in any direction at the outer surface of the test specimen. Premature failure at the corners of the test specimen shall not be considered cause for rejection.

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TABLE 4.7.6 DIAMETER OF FORMER FOR BEND TEST Specified minimum elongation of plate or weld (whichever is lesser) in finished condition

Diameter of former

%

(D)

>24

3T

5.2T

≥18 ≥24

4T

6.2T

<18

6T

8.2T

Free space between supportsat the end of test

LEGEND: T = thickness of test specimens


4.7.7 Corrosion test If a grade of stainless steel has been chosen for its corrosion resistance, corrosion tests may be required to check the suitability of the weld procedure and surface finish for the intended service. The details of the type of corrosion tests and acceptance criteria shall be agreed between the principal and fabricator (see Appendix G). If evidence exists to prove the proposed procedure and surface finish will perform satisfactorily, the corrosion tests may be omitted by agreement between the principal and fabricator. NOTE: For further information on the selection of weld categories, surface finish and corrosion tests see Appendices B and E, and also ASSDA Reference Manual and WTIA Technical Note 13. 4.7.8 Determination of ferrite numbers The ferrite number (FN) of the austenitic or duplex weldments, where required, shall be specified by the principal (see Appendix G). The method of determination shall comply with ISO 8249 or ANSI/AWS A4.2. Alternatively, for austenitic stainless steels, the ferrite number can be calculated using the WRC-1992 diagram (refer to WRC Bulletin 519). NOTE: For guidance on Ferrite Numbers of weld metal, see Appendix F. 4.7.9 Radiography Radiography shall be carried out in accordance with Clauses 6.4.1 and 6.4.2 using the test piece in Figure 4.7.2(a). Ultrasonic examination in accordance with Clause 6.5 may be used in lieu of radiographic testing for thicknesses ≥ 10mm. The weld shall comply with Table 6.3.1. 4.7.10 Retests Where any one specimen of all those tested during a procedure qualification test fails to meet the test requirements, two retests for that particular type of test specimen may be performed with specimens cut from the same procedure qualification test piece. Both retests shall comply with the test requirements. However, if the failure is due to cracking in the heat-affected zone or in the weld, the procedure shall be modified and a new procedure test plate shall be prepared. 4.8 EXTENSION OF QUALIFICATION Procedures qualified for any class of surface quality may be employed without further qualification for a lower class of surface quality. Procedures qualified for any level of internal quality may be employed without further qualification for a lower internal quality level. The above requirements only apply where the same welding method, type of consumable(s) and parent material(s) are used. COPYRIGHT

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AS/NZS 1554.6:2012

4.9 COMBINATION OF PROCESSES For complete penetration or incomplete penetration butt joints— a different process may be used on each side of the one joint, provided that the preparation on the first side is welded in accordance with that listed under the process which is being used, and the angle of the preparation on the second side is in accordance with that listed under the applicable process; and

(b)

a combination of processes may be used on the same side of a joint, provided that the preparation conforms to that listed under the process that is being used for the initial portion of the weld.


(a)

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40

< 5˚

Discard

40 min.

C h a r py V- n otc h te s t p i e c e s A p p r ox . 4 5 0 m m , a c tu a l ove r a l l l e n g t h to s u i t n u m b e r of s p e c i m e n s a p p r o p r i a te to t h i c k n e s s of p l a te a n d r e -te s t requirements

Tr a n sve r s e b u t t te n s i l e C u t a f te r we l d i n g

Macro and hardness Bend

40 min.


Discard 175 m i n .

175 m i n .

(a ) B u t t we l d te s t p i e c e

15 0 m i n . 15 0 m i n .

15 0 m i n . ( b) Fi l l e t we l d te s t p i e c e DIMENSIONS IN MILLIMETRES

FIGURE 4.7.2 FORM AND DIMENSIONS OF WELD TEST PIECES

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4.10 RECORDS OF TESTS The results of all qualification tests carried out (e.g. macro, radiography) shall be recorded and kept together with the relevant welding procedure documents, including the PQR and WPS. These records shall be made available to those authorized to examine them. NOTE: The WPS, PQR and any other supporting documentation may be considered as technical and/or intellectual property of the fabricator and as such, dissemination of this material may be restricted. The extent, type and control of this documentation is the subject of agreement prior to the commencement of the work (see Appendix G). 4.11 REQUALIFICATION OF WELDING PROCEDURES Changes in essential variables require requalification of welding procedure.


Where a change in an essential variable for a welding procedure exceeds the relevant limits given in Table 4.11(A), the welding procedure shall be requalified in accordance with Table 4.7.1. Where a change in an essential variable for a welding procedure exceeds the relevant limits given in Table 4.11(B), the welding procedure shall be requalified by a macro test, taken from either a production weld run-off plate or a special test plate welded for the purpose. NOTE: A change in the pulse parameters includes a change in pulse waveform (Item (p) of Table 4.11(A)) and implies that the welding machine and machine program used to qualify the welding procedure be identified on the welding procedure and used to produce the qualified production welds unless it can be demonstrated that pulse parameters remain unchanged.

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TABLE 4.11(A) CHANGES IN ESSENTIAL VARIABLES REQUIRING REQUALIFICATION Applicability

Nature of change

MMAW

SAW

GMAW

FCAW

GTAW/PAW

(a)

A change from one process to another

X

X

X

X

X

(b)

A change in filler metal or flux classification

X

X

X

X

X

(c)

A change from a hydrogen-controlled consumable to a non-hydrogen-controlled consumable or any increase in hydrogen classification of the consumable

X

X

—

X

—

(d)

A change of shielding gas classification outside the limits of Table 4.11(C)

—

—

X

X

X

(e)

A change of more than ±15% of the specified mean arc voltage of the electrode used for manual metal arc welding process, or more than ±10% for the other processes listed

X

X

X

X

X

A change of more than ±10% of the specified mean welding current for the electrode used for automatic arc welding processes, or more than ±15% for manual metal arc welding

X

X

X

X

X

(g)

A change of more than ±15% of the specified mean speed of travel

X

X

X

X

X

(h)

A change of more than ±25% in the specified number of runs. If the crosssectional area of the preparation is increased, it is also permissible to increase the number of runs in proportion to the increased area

X

X

X

X

X

An increase of 25% or more, or a decrease of 10% or more in flow rate of shielding gas

—

—

X

X

X

A change in position in which welding is done or a change in direction for a vertical weld outside of that permitted by Clauses 4.1.2 and 4.1.3

X

X

X

X

X

A change in welding current form a.c. to d.c. and vice versa or a change in d.c. polarity or a change in metal transfer mode

X

X

X

X

X

A decrease or an increase of more than 20°C in the minimum specified preheat and interrun temperature

X

X

X

X

X

For automatic welding, a change in the number of electrodes used in a multiple wire application

—

X

X

X

X

For butt welds, a change in material thickness outside the range of 0.5 to 2.0 times the thickness of the test plate; see Clause 4.1.2(k)

X

X

X

X

X

(o)

A change in electrical stick out of more than 20%

—

X

X

X

X

(p)

A change in pulse parameter or waveform (see Clause 4.11)

—

X

X

X

X

(q)

For fillet welds, a change from single pass to multi-pass, see Clause 4.1.3

X

X

X

X

X

(r)

For fillet welds, a change in welding position as per Clause 4.5.4

X

X

X

X

X


(f)

(i)

(j)

(k)

(l)

(m)

(n)

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TABLE 4.11(A) (continued) Nature of change

Nature of change

Applicability MMAW

SAW

GMAW

FCAW

GTAW/PAW

Applicability MMAW

SAW

GMAW

FCAW

GTAW/PAW

(s)

For single pass fillet welds, an increase in leg length over the size reported in the qualification

X

X

X

X

X

(t)

A change in material type

X

X

X

X

X


LEGEND: X = applicable — = not applicable

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TABLE 4.11(B) MINOR CHANGES IN ESSENTIAL VARIABLES REQUIRING REQUALIFICATION OF WELDING PROCEDURES BY MACRO TEST Applicability (see Legend)


Nature of change MMAW

SAW

GMAW

FCAW

GTAW/PAW

(a)

A change in the diameter of the electrode

X

—

X

X

—

(b)

A change in electrode diameter of more than one step in the sequence of diameters

—

—

—

—

X

(c)

An increase or decrease in wire diameter of more than one step in the sequence of diameters

—

X

—

—

X

(d)

A change of weld preparation shape (see Note)

X

X

X

X

X

(e)

A change in the shape of any one type of weld preparation more than the tolerance in Clause 5.7.2 and involving the following:

(f)

(g)

(i)

A decrease in the included angle of the weld preparation

X

X

X

X

X

(ii)

A decrease in the root gap of the weld preparation

X

X

X

X

X

(iii) An increase in the root face of the weld preparation

X

X

X

X

X

(iv) The omission of backing material

X

X

X

X

X

A change in electrode geometry beyond the following limits: (i)

Longitudinal spacing of arcs of the greater of ±10%

—

X

—

—

—

(ii)

Lateral spacing of arcs of the greater ±10%

—

X

—

—

—

(iii) Angular rotation of any parallel electrode of ±10%

—

X

—

—

—

(iv) Angle of electrodes:

—

X

—

—

—

(A)

In direction of travel of ±3°

—

X

—

—

—

(B)

Normal to direction of travel of ±5°

—

X

—

—

—

A change in electrical phase sequence between electrodes in multiple electrode welding

—

X

—

—

—

LEGEND: X = applicable — = not applicable NOTE TO TABLE 4.11(B): Examples include but are not limited to a change from V-shape to U-shape and a change from V-shape to a bevel-shape.

TABLE 4.11(C) VARIATION FROM CLASSIFICATION PERMITTED FOR MINOR SHIELDING GAS COMPONENTS Range of minor gas component

Allowed variation of minor gas component

Variation example

≥5 to <50%

±10% relative

16% = 14.4 to 17.6%

<5%

±0.5% absolute

4% = 3.5 to 4.5%

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AS/NZS 1554.6:2012

4.12 QUALIFICATION OF WELDING PERSONNEL 4.12.1 Welding supervisor Welding shall be carried out under the supervision of a welding supervisor employed by or contracted to the fabricator. It shall be ensured that all welding is carried out in accordance with the plans, the qualified welding procedure specifications (WPS), any other documents and the requirements of this Standard. The welding procedure specification shall be made available to the welder at the workplace. Remedial measures shall be taken in cases of imperfections. The welding supervisor may undertake welder qualification tests for those welders under their supervision during the welding of stainless steel. The welding supervisor may also issue and prolong welder qualification test certificates for the welding of stainless steel.


The welding supervisor shall have a minimum of three years experience in the fabrication of welded stainless steel structures and shall comply with one or more of the following: (a)

Hold a Welding Supervisor’s Certificate in accordance with AS 2214, AS 1796 Certificate No. 10, or a New Zealand Institute of Welding Supervisor’s Certificate.

(b)

Hold an International Institute of Welding qualification at the level of International Welding Specialist (IWS), International Welding Technologist (IWT) or International Welding Engineer (IWE) diploma.

(c)

Hold a New Zealand Institute of Welding Certificate in welding engineering.

(d)

Hold postgraduate certificate, diploma or degree in welding engineering from a recognized university or an approved technical college.

(e)

Have other qualifications or experience acceptable to the principal conforming to the requirements of ISO 14731, with specific technical knowledge and experience in the welding of stainless steel. NOTES: 1 Guidance on the minimum technical knowledge requirements for Item (e) is also provided in AS 2214. 2 For the surveillance of the welding works, the welding supervisor can be assisted by other employees of the fabricator with sufficient welding training or experience. This does not affect the responsibility of the welding supervisor.

4.12.2 Welders 4.12.2.1 General Welders shall be suitably qualified to carry out the welding procedures for which they will be employed. The fabricator shall provide evidence acceptable to the principal that the welders are suitably qualified. Such evidence shall be based on welds that closely resemble the joints and their positions to be used in the construction. If a welder repeatedly produces welds not complying with this Standard, further welding by the welder shall be discontinued, until the welder carries out additional tests and the welds so produced comply with this Standard. The names of all welders qualified in accordance with this Clause, together with particulars of any tests passed by each, shall be recorded and made available for perusal by the inspector for the duration of the job. In addition, the requirements of Clauses 4.12.2.2 to 4.12.2.4 apply to the qualification of welders.

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4.12.2.2 Qualification via Standards Qualifications obtained by welders under appropriate Standards laying down welder qualification tests are acceptable as evidence of their ability. Such evidence shall refer to welding carried out on joints and in positions as close as practicable to the actual joints and positions to be used in construction. Welders qualified to Standards such as AS 1796, AS/NZS 2980, AS/NZS 3992, ASME Section IX or ISO 9606-1 shall be deemed to be qualified. 4.12.2.3 Qualification via visual and macro examination Welders not already qualified in accordance with Clause 4.12.2.2 for the welding process and position required by the welding procedure under the conditions of employment shall be required to demonstrate an ability to comply with the appropriate requirements of this Standard by welding a suitable test piece for all welding procedures required on the job. Each test weld shall have a minimum examination length of 300 mm, be examined visually and by means of a macro test or radiography, and shall satisfy corresponding requirements of Clause 6.3.2.


Welder qualifications for welding to a specified welding procedure shall remain valid, provided the following criteria have been met: (a)

It can be shown from records maintained by the organization employing welders that the welders have been employed with reasonable continuity using the relevant welding processes and have continued to produce satisfactory welds as verified by a non-destructive examination.

(b)

The procedure is used within its qualification limits and the following: (i)

Welder qualifications established in any one position described by this Standard are extended within the limits of Table 4.12.2(A). NOTE: The positional qualification limits of the weld procedure are not applicable to welder qualifications.

(ii)

For welds on pipe with an outside diameter d, or hollow sections where d is the dimension of the smaller side, the welder is qualified as follows: (A)

For a test piece with an outside diameter of ≤100 mm, d to 2d.

(B)

For a test piece with an outside diameter of >100 mm, ≥0.5d to unlimited.

(iii) Persons operating automatic or semi-automatic equipment and qualified to use a particular process with an approved consumable or combination of consumables shall be considered qualified to use other approved consumables or combinations of consumables with the same process (see Table 4.12.2(B)). (iv)

Welder qualifications established under Clause 4.12.2.3 with one of the steels covered by this Standard shall be considered as qualification to weld other of the steels according to the following: Stainless steel group

Range of approval

Austenitic

Austenitic

Ferritic

Ferritic, Martensitic

Martensitic

Martensitic, Ferritic

Duplex (ferritic–austenitic)

Duplex, Austenitic

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4.12.2.4 Reapproval Reapproval shall be required if any of the following conditions apply: Six months or more have elapsed since the welder was employed on the relevant welding processes.

(b)

For other than welders qualified to AS/NZS 2980 or ISO 9606-1, the welder changes employment. Under such circumstances, the new employer shall qualify the welder who has changed employment.

(c)

There is some specific reason to question the welder’s ability.


(a)

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TABLE 4.12.2(A) RANGE OF APPROVAL ACCORDING TO WELDING POSITION (See Notes below) Range of approval Plates

Pipes Butt welds

Welding position of approval test piece

Butt welds

Rotat ing

Fillet welds

Plates Fixed

Butt welds

Pipes

— — — — X

X — — —

X

— — — — —

X

X — —

—

H

X

X — — —

X

— — X — —

X

X — —

—

— — — — X — —

—

— — — — —

—

— — —

—

X

— — — — —

X

X — X

—

— —

VU

X — — X

X — —

— X

— — — — —

X

X — X —

X

— — — — —

X

X — —

X

—

— — — — —

X

— — —

—

— — — — — X

VD

— — — — — — —

— — —

—

— — — — —

X

X — —

—

— —

—

— — — — —

—

— — —

—

—

—

— — — — —

X

X — —

—

—

— — — — —

X

X — —

X

— — — — —

X

X — —

—

— — — —

—

— X —

—

VU

— — — — — X

X —

OH

— — — — — X

X — —

X — — — — X

X — — —

— — X — — — — X — —

—

H

X

X

—

— — —

X

X — X

X

X — — — X

X — — —

X

— —

X

X — —

—

X — X

X — X

X

X — — X X

X

X

X

X

X — X

— —

X

— X

—

X — — —

—

X

X — X

X

—

— X —

—

— — —

—

— —

—

—

—

— — — — — X — — — —

—

— — — — —

HV

— — — — — X

X — — —

—

— — — — —

X

VD

— — — — — — — X — —

—

— — — — —

—

—

VU

— — — — — X

—

— — — — —

X

X —

F

0°

HV VD VU (3)

X — — X

HV

VD

F

— — — —

X

(2) Fixed

— — — X

VD

6G—VU X

Fillet welds


F

45° 6G—VD — — X — — — — X — — Rotating

90°

F

VU 90°

0°

H VD VU OH F HV VD VU OH

F 0°

45°

F

F

Rotating

90°

Fixed

6G 6G VD VU H - VU VD

OH

Fillet welds

Rotat ing (2)

Fixed 0°

Butt welds

Fillet welds

X — X —

X

LEGEND:

= welding position for which the welder is approved in the approval list. X = welding positions for which the welder is also approved. = welding positions for which the welder is not approved.

—

NOTES TO TABLE 4.12.2(A): 1 2

The letters in the Table refer to welding positions as defined in Appendix D, except that for vertical welding directions D = down and U = up. Horizontal for pipes may be welded in two versions: (a) Pipe: rotating, axis: horizontal, welds: vertical. (b) Pipe: fixed, axis: vertical, weld: horizontal vertical.

3

OH is an approved position, which is covered by the other related tests.

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TABLE 4.12.2 (B) RANGE OF QUALIFICATION FOR WELDING CONSUMABLES (see Notes) Welding process

Consumable used in the test

Range of qualification Solid wire

Metal core

Flux core

GMAW FCAWgs GTAW

Solid wire

X

X

—

Metal core

X

X

—

FCAW

Flux core

—

—

X

SAW

All (see Note 2)

X

X

X

LEGEND: X = welding consumables for which the welder is qualified — = welding consumables for which the welder is not qualified FCAWgs = flux cored arc welding—gas shielded NOTES: Solid wire consumables for the GMAW and GTAW processes include welding consumables classified and complying with AS/NZS 1167.2 and AS/NZS ISO 14343.

2

The welder is only qualified for flux cored wires specified by the manufacturer as being suitable for the SAW process.


1

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S E C T I O N

5

W O R K M A N S H I P

5.1 GENERAL Stainless steel material should be kept clean, both prior to and after welding. The surfaces shall be free from iron and carbon contamination and the final welds and parent metal shall be free from weld oxides, scale, slag and heat tint, unless otherwise permitted by Section 6. 5.2 TRANSPORT, STORAGE AND HANDLING Packaging shall ensure that mild steel or galvanized truck trays, strapping, chains, slings and fork types do not come into direct contact with the stainless steel. Acceptable packaging and support materials include timber, plastics, cardboard and stainless steel. It is also important to avoid gouges and scratches, which can impair corrosion resistance and surface finish.


Storage shall be in a manner that avoids damage, contamination from chlorides, and maintains a clean surface at all times. Stainless steels shall be stored in a separate area from mild steel. Unlined and unprotected carbon steel racking shall not be used. Lifting grabs, slings, hooks and crowbars shall be used in such manner as to prevent iron and copper contamination and should be lined with non-contaminating material. 5.3 MARKING The performance of stainless steel welded structures can be impaired by certain practices during fabrication. Care shall be taken to ensure the following: (a)

Carbon containing residues are removed prior to welding—these could be included in marking pens or pencils.

(b)

Chlorides are not introduced from marking pens. Any such residues shall be removed.

(c)

Free iron is not left on the surface; residues of iron are possible from vibrating markers or hard stamps that have previously been used on carbon steel or other nonstainless materials. Freedom from steel contamination may be assessed by tests specified in ASTM A380. NOTE: Crevices should not be created by identification markers or labels, tags or beneath marking lines.

5.4 CUTTING Material may be cut to size by shearing, machining, sawing, grinding, laser, water jet or plasma arc. All burrs and ragged edges shall be removed prior to any welding operation. Any cut edge that will be left in the cut condition shall be dressed to remove sharp edges. Machined, sawn, ground and water jet cut edges may be used without further treatment. Sheared, laser, plasma cut and plasma gouge surfaces shall be lightly ground to remove oxides and micro cracks. Edges which have been thermally cut (plasma or laser) will exhibit reduced corrosion resistance. For these edges to achieve their optimum corrosion resistance they must have the damaged material removed by grinding, ideally followed by pickling. Plasma and laser cutting should be carried out on a stainless steel bed. Where this is not possible, iron contamination shall be removed from surfaces adjacent to the cut edge. Carbon arc gouging is not recommended. If it has been used, carbon arc gouged surfaces require a heat affected layer of 1.0 mm minimum to be dressed from the cut edge. COPYRIGHT

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5.5 FABRICATION Stainless steel fabrication should be carried out in dedicated areas separated from carbon steel fabrication. Special care shall be taken to avoid contamination of the job with grinding debris. Tools and equipment, such as chipping hammers, wire brushes or work return clamps, shall be made from or faced with stainless steel. Grinding and polishing wheels, disc belts and tools shall be dedicated for use on stainless steel only. Stainless steel shall not come into direct contact with mild steel manipulators, rotators, trestles, clamps or other handling aids. All practical measures shall be taken to prevent iron contamination by forming and handling equipment. 5.6 PREPARATION OF EDGES FOR WELDING


Surfaces and edges to be welded shall be uniform and free from fins, tears, cracks and other defects which would adversely affect the quality or strength of the weld. Surfaces to be welded and surfaces adjacent to a weld shall also be free from scale, slag, rust, grease, marking crayons, paint, grinding debris or other foreign matter, particularly compounds containing carbon and low melting point metals such as copper and zinc. 5.7 ASSEMBLY 5.7.1 General The alignment of parts to be welded shall be made as carefully as possible having regard to the normal tolerances associated with the fabrication and erection procedures specified in the application Standard. 5.7.2 Alignment and dimensional tolerances of butt-welded joints Ends of parts to be joined by butt welds shall be carefully aligned, having regard to the procedure being employed. The surfaces of plates shall not be out of alignment by more than the permissible levels given in Table 6.3.2. The dimensions of butt-welded joints which differ from those shown on the detailed drawings or other documents by more than the tolerances shown in Table 5.7.2 shall be referred to the inspector for approval. Root openings wider than those permitted in Table 5.7.2, but not greater than twice the thickness of the thinner part or 19 mm, whichever is the lesser, may be corrected by welding to acceptable dimensions prior to joining of the parts by welding. Root openings wider than twice the thickness of the thinner part, or 19 mm, shall be corrected by welding only with the approval of the principal.

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TABLE 5.7.2 ALLOWABLE JOINT TOLERANCES Dimension

Tolerance

Root face (root not gouged)

±1.0 mm

Root gap without backing (root not gouged)

±1.5 mm

Root radius (root not gouged)

+3, −0 mm

Root gap with backing

+4, −1.5 mm

Angle of preparation

+10, −5°

5.7.3 Alignment of fillet welds and incomplete penetration butt welds


Except for full contact joints, parts to be joined by fillet welds or by incomplete penetration butt welds parallel to the length of the member shall be brought into as close contact as practicable. The gap between parts shall normally not exceed 5 mm except in cases involving rolled shapes and plates 75 mm or greater in thickness if, after straightening and on assembly, the gap cannot be closed sufficiently to comply with the requirement. In such cases, a maximum gap of 8 mm is acceptable provided that a sealing weld or suitable backing material is used to prevent burn through. If the separation is 1.5 mm or greater, the size of the fillet weld shall be increased by the amount of the separation or the fabricator shall demonstrate that the required design throat thickness has been obtained. 5.7.4 Separation of a backing material The separation between the faying surfaces of butt welds and permanent backing material shall not exceed 1.5 mm. 5.8 BACKING MATERIAL The selection of backing material should be agreed with the principal. Temporary backing bars, especially those made of copper shall contain an appropriate groove and weld parameters shall be modified to avoid copper pickup in the weld. Permanent backing material shall be of the same grade as the structure unless otherwise agreed with the principal. Where permanent backing is exposed to corrosive media it should be seal welded to the structure. Backing bars shall be free from grease, moisture and oxide.

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5.9 ARC ENERGY INPUT Arc energy input from the welding process shall be carefully controlled and should be calculated using the following equation: Arc energy input (kJ/mm) =

60 EI 1000 V

where E

= arc voltage, in volts

I

= welding current, in amperes

V

= welding travel speed, in millimetres per minute.


To calculate the total arc energy input for multi-arc processes, the arc energy input for each individual arc shall be calculated using the above equation. The total arc energy input for the process is the sum of all arc energy inputs for each individual arc. NOTES: 1 For pulsed mode welding, use E = average voltage and I = average current to calculate the minimum arc energy. Recommended arc energy input ranges are given in Table 5.10. For waveform controlled welding (including pulsed spray and controlled short circuiting metal transfer modes) advice should be sought from the welding machine supplier on the calculation of arc energy. ASME Section IX also provides for the determination of arc energy of waveform controlled welding. 2 The permitted heat input range (see Clause 5.10) should be shown on WPS documents and be calculated using low-low-high (amps-volts-welding speed) parameters for the minimum arc energy and high-high-low (amps-volts-welding speed) parameters for the maximum arc energy.

5.10 PREHEATING AND INTERRUN CONTROL If preheating is required before each weld run is started, the surface of all areas within 75 mm of the joint should be heated to the temperature recommended in Table 5.10. Embrittlement may be experienced with martensitic stainless steels if the interrun temperature is allowed to fall below the temperature recommended in Table 5.10. Therefore, maintaining the preheat temperature between runs is recommended, or heating the joint to the postweld heat treatment temperature before allowing it to cool to ambient temperature. Further tempering may also be required in accordance with the steel manufacturer’s recommendations. Heating may be carried out by any suitable method provided it is uniform and causes no contamination of the metal surface. The heat of welding may assist in maintaining preheat temperatures. The temperature of the metal surfaces adjacent to the weld should be checked by the use of chloride free temperature-indicating crayons, thermocouple pyrometers or other suitable methods. Temperature should not be checked within 2 min. of cessation of preheating and welding. The measurement of preheat and interrun temperatures shall comply with AS ISO 13916. 5.11 WELDING UNDER ADVERSE WEATHER CONDITIONS Welding shall not be carried out when the welding surfaces are wet. Welding during periods of high wind is only permitted if the welder and their work are properly protected. Welding processes requiring an external gas shield shall not be carried out in a draught or wind greater than 3 km/h unless the welding area is suitably protected so as to reduce the wind to below 3 km/h or unless a satisfactory welding procedure is established in accordance with Section 4.

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TABLE 5.10 RECOMMENDED PREHEAT AND INTERRUN TEMPERATURE AND ARC ENERGY INPUT Material Typical specifications or nominal compositions


Type

Minimum preheat temperature °C (see Notes 1, 4 and 6)

Maximum interrun temperature °C (see Note 2)

Arc energy input kJ/mm

Martensitic chromium steel

Types 410, 420

200

300

1.0 to 2.5

Ferritic chromium steel

Types 430, 444

10

100 (see Note 5)

1.0 max.

12%Cr Ferritic chromium steel

Types 1.4003

10

150 (see Note 5)

0.5 to 1.5

Austenitic Cr-Ni steel

Types 302, 304, 304L 310S, 316, 316L, 321, 347

5

150

1.5 max.

Fully austenitic Cr-Ni steel

Types 310, 904L, 6% Mo

5

100

1.0 max.

Ferritic—austenitic (Duplex) Cr-Ni steel

S32304, S32205, S31803

10

150 (see Note 4)

0.5 to 2.5

Super duplex (see Notes 3 and 4)

S32520, S32750, S32760

10

150 (see Note 4)

0.5 to 1.5

NOTES: 1

Higher temperatures may be required to achieve the qualified welding procedure, and lower temperatures may be adopted with some high heat input processes. The maximum preheat temperature shall not exceed the maximum interrun temperature.

2

The minimum interrun temperature shall not be less than the minimum preheat temperature.

3

Super duplex as defined by pitting resistance equivalent number ≥40.

4

Exceeding heat input or interpass temperatures or multiple welding in one location will promote weld defects such as deleterious phase formation, loss of ductility or hot cracking.

5

Exceeding heat input or interrun temperatures may cause grain growth and loss of ductility.

6

For ferritic and duplex stainless steels higher preheat may be required if the dewpoint is within 3°C of the metal temperature.

5.12 TACK WELDS Tack welds which are to be incorporated in the final weld or those which are to remain on the structure shall comply with the following requirements: (a)

Be subject to the same composition, quality and workmanship requirements as the final welds including gas shielding and/or post weld cleaning.

(b)

Have cascaded ends if multi-run and— (i)

for other than martensitic stainless steels, a length of not less than two times the thickness of the thinner part or 40 mm, whichever is the lesser; or

(ii)

for martensitic stainless steels, a length of not less than two times the thickness of the thicker part or 40 mm, whichever is the lesser. NOTE: Tack welds not incorporated in the final weld can act as sites for corrosion. Approval of the principal should be sought. Further guidance on tack weld recommendations can be found in ISO/TR 17671-3. (c)

Have a length of not less than two times the thickness of the thinner part or 40 mm, whichever is the lesser.

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5.13 INTERRUN CLEANING Interrun cleaning, where required, shall be carried out using a stainless steel wire brush or iron-free and sulphur-free grinding media suitable for stainless steel. 5.14 WELD DEPTH-TO-WIDTH RATIO Neither the depth nor the maximum width in the cross-section of weld metal deposited in each weld run shall exceed the width at the surface of the weld run (see Figure 5.14). This requirement may be waived only if the testing of a welding procedure which strictly replicates the work regarding thickness, restraint and welding preparation has demonstrated that such welds are free from cracks. 5.15 CONTROL OF DISTORTION AND RESIDUAL STRESS 5.15.1 General


In the assembly and joining of parts of a structure or of built-up members, and in the welding of reinforcing parts to members, the clamping, jigging, tacking and welding procedures and sequence shall be such as will maintain distortion and shrinkage within the limits specified by the principal. If heat sinks are used, care shall be taken to avoid contamination of the weldment.

W i d t h of f a c e

D e pth Width

W i d t h of f a c e

Width

D e pth

FIGURE 5.14 UNACCEPTABLE WELD RUN IN WHICH DEPTH OR WIDTH, OR BOTH EXCEED THE WIDTH OF THE WELD FACE

5.15.2 Welding and cutting under applied stress Parts that are stressed shall not be cut or welded except where— (a)

the effect of such actions on the flexural tensile and compressive capacity of the member is considered;

(b)

the matter is discussed between the fabricator and the principal in accordance with Appendix G; and

(c)

appropriate safety precautions are taken to prevent damage to or failure of the structure.

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5.15.3 Correction of distortion Distortion resulting from welding and fabrication may be corrected by mechanical means, or by the controlled application of weld runs. Spot or line heating may also be used for low carbon and stabilized austenitic stainless steels as well as lean duplex stainless steel. Spot or line heating may not be suitable for standard and high alloyed austenitic and duplex grades, nor for ferritic or martensitic grades with greater than 13% Cr. When heating of these grades is unavoidable, the approval of the principal is required. 5.16 BACKGOUGING AND REPAIR OF DEFECTS IN WELDS 5.16.1 General


Where welds are found to have defects as classified by Clause 6.7, either the defects shall be repaired, or the entire weld shall be removed and replaced. Repairing or rewelding shall be carried out in accordance with this Standard, and the principal shall be advised of all such repairs. A repair weld procedure may be required in such instances. NOTE: The principal may require that a welding procedure for repairs be qualified and approved. 5.16.2 Removal of weld metal Removal of the weld metal or portions of the base metal by machining, grinding, chipping, or plasma gouging, shall not nick or undercut the remaining weld metal or base metal. Unacceptable portions of the weld shall be removed, without substantial removal of the base metal. The surfaces shall be cleaned thoroughly before welding. Gouged areas requiring rewelding shall have a root radius of not less than 5 mm and sufficient width to allow the welder reasonable access to reinstate the weld. Unacceptable undercutting shall be made good by the deposition of additional weld metal in accordance with this Standard or by the removal of the undercut by grinding in accordance with Clause 5.16.3. 5.16.3 Grinding Grinding shall comply with the following requirements: (a)

Grinding shall not overheat the metal as heavy pressure or too rapid removal of metal may lead to heat tint.

(b)

The area ground shall blend smoothly into the surrounding surface without abrupt changes in contour.

(c)

The grinding shall not extend below the surface of the parent material by more than— (i)

for material less than 10 mm thick, 0.5 mm; or

(ii)

for material not less than 10 mm thick, the lesser of 0.07 times the nominal thickness and 3 mm.

(d) Grinding wheels shall be dedicated for stainless steel work only. NOTES: 1 Ceramic bonded ulphur-free grinding wheels are recommended. 2 Where resin bonded grinding wheels are used, care should be taken to prevent smearing of resin on the material surface.

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5.16.4 Stop/Starts Where stop/starts occur in the length of a continuous automatic longitudinal fillet or butt weld designated for fatigue applications, they shall be repaired by the following procedure: (a)

Grind the stopped end of the weld so that it tapers to the root of the joint with a slope of at least 4:1.

(b)

Restart the weld from the top of the taper slope.

(c)

Grind the repaired weld to a smooth surface.

The site of the repair shall be subjected to 100% liquid penetrant examination in accordance with Section 6. NOTE: In rectangular hollow section joints, weld stops and starts should be avoided at corners.


5.17 TEMPORARY ATTACHMENTS Welds joining temporary attachments to the structure shall be made to the same standards as final welds. Temporary attachments shall be constructed from the same material as the structure; alternatively a temporary compensating pad of the same material shall be used. All temporary attachments shall be removed unless otherwise specified on the drawings or other documents. Temporary welds and attachments shall not be allowed on the tension flanges of beams, girders and similar members. When temporary welds or attachments are removed, the surface shall be— (a)

reinstated to a reasonably smooth condition by grinding or by a combination of welding and grinding;

(b)

checked by liquid penetrant examination or other suitable method to ensure soundness; and

(c)

finished to the requirements of Clause 5.16.2.

5.18 ARC STRIKES Arc strikes outside the area of permanent welds should be avoided on any material. The consequences of stray-arc strikes can be serious as localized overheating can cause micro cracks which may result in crevice corrosion in service. Cracks, blemishes or heat tint resulting from arc strikes on members shall be ground to a smooth contour in accordance with Clause 5.16.3 and checked by liquid penetrant examination or another suitable method to ensure soundness. 5.19 CLEANING OF FINISHED WELDS Slag shall be removed from completed welds. The weld and adjacent base metal shall be cleaned by brushing or other suitable means in accordance with the requirements of the specified surface finish. NOTE: Stainless steel wire brushing will burnish the surface and will not remove the less corrosion resistant, chromium depleted layer. It is most effective if the weld is warm while brushed.

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5.20 DRESSING OF BUTT WELDS Where, for any reason, it is required that butt welds be dressed flush, the surfaces shall be finished, without— (a)

reducing the thickness of the thinner base metal or weld metal by more than 0.8 mm or 5% of the thickness, whichever is the lesser; or

(b)

leaving reinforcement that exceeds 0.8 mm.

All reinforcement shall be removed where the weld forms part of a faying or contact surface. Any dressing of reinforcement shall blend smoothly into the plate surfaces. 5.21 LEAK TEST WATER Water for testing stainless steel fabrications shall be potable with chloride levels agreed between fabricator and purchaser and preferably below 50 ppm.


Test temperatures shall be agreed and preferably below 30°C. Untreated river or natural waters shall not be used. The fabrication shall be drained (with care to avoid ponding) and dried promptly after testing and certainly within 24 hours. Re-used test water shall be clean and biologically inactive.

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S E C T I O N

6

Q U A L I T Y

O F

W E L D S

6.1 CATEGORIES OF WELDS According to the intended application, welds shall be Category 1A, 1B, 1C, 2A, 2B, 2C or FA in accordance with Table 6.1. Guidance on selection of weld category and surface finish is given in Appendix B. The compliance of the completed welds with these categories shall be determined in accordance with the different inspection requirements and different acceptance levels of imperfections for the categories, as given in Clause 6.3. TABLE 6.1 CATEGORIES OF WELD


Category designation

Level of internal imperfections

Class of surface imperfections (See Table 6.3.2)

1A

1 See Table 6.3.1 (A)

A

1B


B

1C


C

2A

2 Not subject to examination

A

2B


B

2C


C

FA

F See Section 1.6.3 and Table 6.3.1 (B)

A

6.2 SURFACE FINISHES OF WELDS 6.2.1 General The condition of weld seams shall be dependent on the intended application or function of the equipment or structure of which they are a part. The surface condition of the weld shall be designated as conditions I, II or III in accordance with Table 6.2.1, and Clauses 6.2.2 to 6.2.6, and Table 6.3.3 as appropriate. Guidance on selection of weld category and surface finish is given in Appendix B.

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TABLE 6.2.1 SURFACE CONDITION OF WELDS (see Notes 1, 2) Surface condition (Note 3) I (see Clause 6.2.2)

II (see Clause 6.2.3)

III (see Clause 6.2.4)

Surface treatment Mechanically polished, Electropolished, Chemically treated, As-welded (see Note 4) Mechanically treated, Electropolished, Electrocleaned, Chemically treated, As-welded Slag removed or wire brushed or both As-welded

Chemical treatment (see Clause 6.2.6)

Acceptance criteria

Optional

Optional

See Table 6.3.3

No

NOTES:


1

Finishes may be mixed, e.g. Grade II or III finish one side and Grade I finish the other side. Also see Clause 6.2.3.

2

Cleaning, descaling and passivation procedures should generally follow ASTM A380.

3

Guidance to choice of surface finish is given in Appendix B.

4

For high quality automatically produced welds by welding processes PAW and TIG.

6.2.2 Surface Condition I—Polished For Surface Condition I, the weld reinforcement shall be removed by grinding or linishing if the welded zone is to be polished to a specified finish (see Clause 6.2.5). Automatically produced welds by welding processes PAW and Gas Tungsten Arc Welding (TIG) shall not be subjected to grinding and polishing if they meet the Ra value specified (see Clause 6.2.5). As the final operation, chemical cleaning or electropolishing according to ASTM B912 and/or ISO 15730 may be used to improve corrosion resistance of the surface. 6.2.3 Surface condition II—Cleaned For Surface Condition II, the weld and heat affected area shall be protected from oxidation during welding or cleaned by any of the following processes as specified by the principal: (a)

Acid pickling and passivation (refer to ASTM A380) Welds shall be cleaned of all slag and flux residues. The structure shall then be acid pickled (usually with nitric/hydrofluoric acid mixtures) by placing it in a bath, or by swabbing the area or by application of a pickling paste, until all traces of the heat tint and oxides are removed. This process may be assisted by mechanical agitation or brushing. Pickling acids should be chloride free (refer to WTIA Technical Note 16). Passivation, usually by nitric acid, shall be included in this treatment, with the aim of restoring the chromium oxide surface layer. Commercial pickling pastes and baths include nitric acid. A subsequent passivation by nitric acid alone will further increase the corrosion resistance against aggressive environments and should be specified in these circumstances. The surface shall then be washed clean of all residues using fresh clean water. Care should be taken to conform with health and safety instructions.

(b)

Electropolishing (refer to ASTM B912 and/or ISO 15730) may be used as an alternative to pickling to remove imperfections from the surface of stainless steel. It may be used as a final operation after wire brushing (see item (d)) and buffing or linishing (see item (e)) in order to improve corrosion resistance of mechanically treated surfaces. The treatment should be carried out such as to ensure complete removal of both the dark oxide and underlying chromium-depleted layer, if full COPYRIGHT

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corrosion resistance is to be achieved. Because electropolishing cannot penetrate insulating slag and scale, it is common to acid pickle weld zones prior to electropolishing the entire surface. This provides a luster and slightly reduces the surface roughness by removing sharp edges and peaks of polishing lines. (c)

Electrocleaning is performed using portable machines, locally applying the same process as electropolishing with either acidic or neutral solutions. This technique effectively removes weld oxidation and passivates the surfaces without the need for aggressive pickling acids. The surface may not be highly polished, but is effectively cleaned by this process. The chromium depleted layer may not be fully removed on thick weldments with high heat input, if low current density and short dwell times are employed.

(d)

Stainless steel wire brushing The straw-coloured oxide (AWS D18.2 Class 3) of GTAW welds may be removed immediately after welding by brushing with a stainless steel wire brush.

(e)

Abrasive polishing of weld and adjacent areas The weld and heat affected zone shall be buffed or linished to remove all oxides. The final finish is to be specified by the principal. Passivation may be required to restore corrosion resistance in aggressive environments.

(f)

Abrasive blasting Abrasive grit blasting of the weldment may be used, provided that the grit is iron free. Typically alumina, garnet and silicon carbide are used. Steel grit shall not be used as the surface will be roughened and more difficult to clean. It will also require passivation if used in aggressive conditions as sulphide inclusions will be exposed.

(g)

Gas purging Inert gas purging of the weld penetration and any heat affected areas is used where the welds cannot be accessed for mechanical cleaning or pickling (see Clause 6.2.6).

(h)

Gas shielding The welded zone can be left as-welded where the weld and heat affected zone have a low degree of oxidation (see Clause 6.2.6). NOTE: Care is needed when using mechanical methods of cleaning (Items (d), (e) and (f)). Overheating of material when using rotary buffing equipment and cross contamination should be avoided. Pickling and/or passivation, or electropolishing may be used as a final operation to improve corrosion resistance of the steel surface.

6.2.4 Surface condition III—As-welded Surface Condition III does not impose heat tint limits and is only suitable if appearance and corrosion resistance are not important. (See Clause 5.19). 6.2.5 Surface roughness The finish shall be specified by the principal (see Appendix G) by one of the following methods: (a)

Surface roughness (Ra) value as defined in AS 2382 or ASME B46.1.

(b)

Sample comparison.

Maximum roughness R max value may be specified by the principal in addition to Ra (see Appendix B). The principal and the fabricator should agree upon the finishing procedure used. If surface roughness is defined according to Item (b), the principal and the fabricator shall retain corresponding samples or photographs of them.

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6.2.6 Surface discoloration The weld and heat-affected zone surface may be permitted to have light straw colour oxide (for example, AWS D18.2 Samples 1 through 3, as shown in Figure 6.2.6, can be used as a guide). For product contact surface, blue, brown or black oxide heats (Sample 4 and above) shall not be acceptable. Any discoloration shall be so tightly adhering to the surface that normal operations will not remove it. Post-weld conditioning may be specified by the principal to meet discoloration requirements.


The principal and the fabricator should agree upon the acceptable degree of weld discoloration either using the weld discoloration levels of AWS D18.2:2009 in Figure 6.2.6 or by sample comparison (see Table 6.3.3).

(Reproduced with permission from the American Welding Society (AWS), Miami, FL.)

FIGURE 6.2.6 WELD DISCOLORATION LEVELS ON INSIDE OF AUSTENITIC STAINLESS STEEL TUBE ACCORDING TO AWS D18.2:2009

6.3 METHODS OF IMPERFECTIONS

INSPECTION

AND

PERMISSIBLE

LEVELS

OF

6.3.1 Methods of inspection of completed welds All welds shall be inspected in accordance with Clause 7.3 and, where appropriate, with Clause 7.4. In addition, where radiographic or ultrasonic examination is required by the principal and is specified on the drawings or other documents, examination for the relevant types of imperfections shown in Tables 6.3.1(A) and (B) shall be carried out in accordance with Clause 6.4 or Clause 6.5, as applicable. NOTE: Table 7.4 contains guidance on the suggested extent of non-destructive examination, which is consistent with the principles on which this Standard is based. 6.3.2 Permissible levels of imperfection The size, number and spacing of imperfections permitted for the weld categories shall not exceed the relevant levels given in Tables 6.3.1(A) and (B) and Table 6.3.2.

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TABLE 6.3.1(A) PERMISSIBLE LEVEL OF INTERNAL IMPERFECTIONS AS DETERMINED BY RADIOGRAPHIC OR ULTRASONIC EXAMINATION FOR WELDS OF CATEGORY 1A, 1B and 1C (see notes 1 and 2) Weighting factor Type of imperfection

Thickness of thinner parent metal (t) mm

Cracks Inclusions, lack of penetration or lack of fusion

Height of imperfection (h), mm (see Note 3)* ≤2

>2 ≤4

>4 ≤10

All

Porosity

>20

Not permitted ≤10 ≤20 ≤40

>10 >20 >40

>10 ≤20

Maximum permissible level (see Notes 4, 5 and 6)*

2 2 1 1

X 4 2 2

X X 5 5

All

X X X 10

X X X X

L/5 L/4 L/2 L

see Note 8*


TABLE 6.3.1(B) PERMISSIBLE LEVEL OF INTERNAL IMPERFECTIONS AS DETERMINED BY RADIOGRAPHIC OR ULTRASONIC EXAMINATION FOR WELDS OF CATEGORY FA (see note 2) Weighting factor Type of imperfection

Thickness of thinner parent metal (t) mm

Height of imperfection (h), mm (see Note 3)* ≤2

Cracks Inclusions, lack of penetration or lack of fusion Porosity

>2 ≤4

All

>4 ≤10

>10 ≤20

>20

Not permitted ≤10 ≤20 ≤40

>10 >20 >40

Maximum permissible level (see Notes 4, 5 and 6)*

X 4 2 2

X 8 4 4

All

X X 10 10 see Note 8*

LEGEND X = Not permitted L = Weld length under consideration

* Notes appear on following page. COPYRIGHT

X X X 20

X X X X

X L/8 L/4 L/2

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NOTES TO TABLES 6.3.1(A) and 6.3.1(B): 1

Welds in Categories 2A, 2B and 2C are not subject to radiographic or ultrasonic examination.

2

For adjacent imperfections, see Clause 6.3.3.

3

For the purpose of radiographic examination or routine ultrasonic examination, h is to be taken as 2 mm. If the ultrasonic or radiographic examination indicates that h may be greater than 2 mm, h is to be determined by sectioning or vertical ultrasonic sizing.

4

For any weld length under consideration, the imperfection level is calculated by multiplying the length of each imperfection by its weighting factor and adding these weighted lengths to determine a total imperfection level. The total imperfection level shall be less than the maximum permissible imperfection level.

5

No imperfection exceeding a height of t/20 or 2 mm (whichever is the greater) shall be permitted within a distance of t of the end of a weld.

6

Where the length of a continuous weld exceeds 1 m, the maximum permissible imperfection level shall not be exceeded in any continuous weld length of 1 m.

7

Where continuous or adjacent imperfections cross the division between the examination lengths, the examination length shall be relocated to include the most severe combination of imperfections.

8

Internal porosity is not considered to be a particularly serious imperfection in terms of this Standard and is cause for rejection of a weld only where it is present in sufficient quantity to render inspection difficult for the other imperfections listed in Table 6.3.1(A) and 6.3.1(B). Where such a level of porosity is present, it shall be recorded and referred to the principal for consideration. For radiographic inspection, porosity levels representing a loss of projected area not exceeding 2% are permitted. If required, reference may be made to porosity charts in AS 4037, to assist in assessing the appearance of this level of porosity on a radiograph.

6.3.3 Adjacent imperfections 6.3.3.1 Aligned Where adjacent imperfections are aligned, they shall be assessed as shown in Item (a) of Figure 6.3.3. 6.3.3.2 Overlapping Where there is a horizontal displacement between adjacent imperfections, the effective length (L) shall be as shown in Item (b) of Figure 6.3.3. 6.3.3.3 Overlapping vertical displacement Where imperfections occur one above the other in the vertical plane of the weld, they shall be assessed as shown in Item (c) of Figure 6.3.3.

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TABLE 6.3.2 PERMISSIBLE LEVELS OF SURFACE IMPERFECTIONS REVEALED BY VISUAL AND LIQUID PENETRANT EXAMINATION (see Notes and Figure 6.3.2) Imperfection Type


Cracks

Maximum allowable dimension or number of imperfections for butt welds Parameter

Class A (See Note 5)

Class B

Class C

Length (L)

Nil

Nil

Crater cracks only

Cumulative length (Σ)

6 mm in 1000 mm of weld (crater cracks only) For For For For

Reinforcement

Height (h)

0.8 mm (see Note 4)

Excess penetration

Height (h)

As for reinforcement

Length (L)

Nil

t< 6 mm: 1.5 mm 625 mm: 6 mm

Nil

Overlap

30 mm in 300 mm, but proportionately less for shorter lengths

Length (L)

Where located more than 3t from the end of a weld, 2t/3, but not greater than 20 mm. Where located within 3t from the end of a weld, 3 mm.

Nil

Nil

t in 6t length, but proportionately less for shorter lengths


Surface porosity

t, but not greater than 10 mm


Lack of fusion

Undercut

Not specified

Depth (h)

Nil

t/10 but not greater than 0.5 mm

t/10 but not greater than 0.5 mm

Size of pore (d)

Nil

Nil

t/3 but not greater than 2 mm

Number of pores

Shrinkage groove or root cavity

2 pores per 12t length

Nil

Nil

As for undercut

5% but not greater than 1.5 mm

10% but not greater than 3 mm

10% but not greater than 3 mm

Crater, solid inclusion, poor restart, spatter, torn surface, grinding mark, chipping mark

Nil

Nil

Not specified

Weld bead width

Straight and uniform

Not specified

Not specified

Linear misalignment

Depth (h)

(continued)

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TABLE 6.3.2 (continued) Imperfection Type

Maximum allowable dimension or number of imperfections for butt welds Parameter

Class A (See Note 5)

Imperfection

Reinforcement

Undersize— Intermittent (See Note 3) Other Imperfections

Class B

Class C

Imperfections for fillet welds

Height (h)

Flat or concave, smoothly blended at toes (See Note 6)

For S<12 mm:1 mm For S≥12 mm: 2 mm

Not Specified

S/10 but not greater than 2 mm



As for butt welds


NOTES: 1

For adjacent imperfections, see Clause 6.3.3.

2

For a welding procedure qualification, the assessment of the test piece for compliance with the permissible levels of imperfections should be done with the aid of the macro test specimen. For calculation of the loss of cross-sectional area, internal imperfections are estimated from the macro test specimen.

3

The cumulative length of intermittent undersize fillet welds shall not exceed 10% of the length of the weld.

4

All reinforcement is to be removed according to Clause 5.20, and the surface to be finished as specified. High quality automatically produced welds by welding processes PAW and TIG need not be dressed provided they meet requirements of this standard.

5

For hygienic applications, where the process-contact surface of the weld is to be used as is, welding process shall be limited to the automatic PAW and TIG. Autogenous welds and welds with filler wire are acceptable provided they meet requirements of this standard.

6

For FA fillet welds, the angle β between the plane tangential to the weld bead surface at the toe and the plane through the line PQ shall be less than or equal to 15°. Slightly concave welds shall be acceptable provided the design throat thickness requirement is fulfilled. This requirement also applies for the angle between the tangential planes between multi-runs.

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h

L t h h (a) B u t t we l d

t d L


h

h

L

S ( b) F i l l e t we l d

FIGURE 6.3.2 DIMENSION OF SURFACE IMPERFECTIONS SPECIFIED IN TABLE 6.3.2

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TABLE 6.3.3 ACCEPTANCE CRITERIA FOR SURFACE CONDITION I, II AND III REVEALED BY VISUAL EXAMINATION Imperfection Type Discoloration (see Clause 6.2.6)

Roughness (see Note 3) (See Clause 6.2.5) Maximum Roughness R max (see Note 4)

Acceptance criteria Parameter

Condition I

Condition II

Condition III

Colour of oxide on the weld and HAZ surface

Nil (AWS D18.2 samples 1)

AWS D18.2 samples 1 through 3 or as specified by the principal

Not specified

(a) R a (see Note 1) (b) Sample comparison

As specified by the principal (see Note 2)

As specified by the principal

Not specified

R max



Not specified


NOTES: 1

R a values for surface roughness shall be determined according to the AS 2382 or ASME B46.1 and Clause 6.2.5.

2

R a value shall be specified by the principal for welds left in an as welded condition.

3

R a of an abraded finish in corrosive service should have a transverse R a <0.5 µm with a clean cut surface finish.

4

R max may be specified for cleanability in hygienic service.

6.3.4 Qualifications of welding procedure by macro test and side-bend test (also see Clause 4.7) Where qualification by macro test and side-bend test is required (see Table 4.7.1), the bend test shall be used solely to reveal imperfections not observed in the macro-section. Tearing at the ends of imperfections shall not be considered for the purposes of assessing the depth or height of imperfections. Any imperfections observed may be assumed to extend the total length of the weld unless additional sections are taken to show the extent of the imperfections. 6.4 RADIOGRAPHY 6.4.1 Method When required, radiography shall be carried out in accordance with AS 2177.1, using method XR2/-, GR1/- or GR2/- as follows: (a)

For thicknesses ≤12 mm: XR2/-, GR1/- or GR2/-.

(b)

For thicknesses >12 mm: XR2/- or GR2/-.

Where materials of different thicknesses are examined, the technique shall be selected according to the thicker plate. NOTE: For thickness <6 mm, method XR1/- may be used by agreement between the principal and the fabricator, and the use of gamma radiography should be avoided.

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L1 d L2

W h e r e d i s l e s s th a n L1 th e s m a ll e r i m p e r fe c t i o n, L = L1 + L 2 + d W h e r e d i s n ot l e s s th a n L1 t h e s m a ll e r i m p e r fe c ti o n, L = L1 + L 2

(a) A li g n e d i m p e r fe c ti o n s

L1


L L2

( b) O ve r l a p p i n g i m p e r fe c ti o n s L1 h1 d h2

L2 N OT E : Tr e a t a s s e p a r a t e d e f e c t s .

( i ) C r o s s - s e c ti o n

( ii ) Lo n g i tu di n a l s e c ti o n, w h e r e d > 5 m m h1 d

h

h2

L

N OT E : Tr e a t a s a s i n g l e d e f e c t w i t h d i m e n s i o n s h a n d L a s s h ow n . ( iii ) Lo n g i tu di n a l s e c ti o n, w h e r e d < 5 m m (c) O ve r l a p p i n g ve r ti c a l d i s p l a c e m e n t

FIGURE 6.3.3 ASSESSMENT OF ADJACENT IMPERFECTIONS

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6.4.2 Image quality indicator (IQI) sensitivity The minimum IQI sensitivity for each technique shall be as required by Table 6.4.2. The IQI sensitivity shall be measured through the weld using wire type IQI in accordance with AS 2177.2. At least one IQI should be used with each radiograph. 6.4.3 Acceptance limits The maximum permissible levels of imperfections shall be as given in Table 6.3.1(A) and 6.3.1(B). Where imperfections are detected in excess of the limits of Table 6.3.1(A) and 6.3.1(B), the unacceptable areas may be repaired and re-radiographed in accordance with this Clause (6.4.3). TABLE 6.4.2 MINIMUM DISCERNIBLE WIRE Wire number (see AS 2177.2)


Method

Weld metal thickness, mm ≤6

>6 ≤10

>10 ≤12

>12 ≤18

>18 ≤25

>25 ≤35

>35 ≤50

XR2/- and GR1/-

13

12

11

10

9

8

7

GR2/-

12

11

11

10

9

8

7

NOTE: Above 50 mm thickness, the minimum IQI sensitivity shall be 2.0%.

6.5 ULTRASONIC EXAMINATION 6.5.1 Method When required, ultrasonic examination shall be carried out in accordance with ISO 22825 or by an approved method agreed between the principal and fabricator. 6.5.2 Acceptance limits The maximum permissible levels of imperfections shall be as given in Table 6.3.1(A) and 6.3.1(B). Where welds fail to meet the criteria of Table 6.3.1(A) and 6.3.1(B), they shall either be repaired and retested, or considered defective and dealt with in accordance with Clause 6.7. NOTE: Where non-complying welds are detected during a spot examination, two additional spots, each of the same length as the original spot, should be examined. They should comply with the following requirements, as appropriate: (a) Where the two additional spots pass, only the original spot should be repaired and re-examined. (b) Where either of the two additional spots fail, the entire weld should be examined, and repaired as appropriate. (c) Refer to AS 4037 for guidance on minimum spot size. 6.6 LIQUID PENETRANT EXAMINATION 6.6.1 Method Where required, penetrant examination shall be carried out in accordance with one of the techniques of AS 2062. 6.6.2 Acceptance limits The maximum permissible levels of imperfections shall be as given in Table 6.3.2.

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6.7 WELD DEFECTS Weld imperfections that exceed the levels given in Tables 6.3.1(A), 6.3.1(B) and 6.3.2 shall be classed as defects. However, where it can be demonstrated, by the use of fracture mechanics or other suitable methods of assessment, that the defects will not be injurious to the performance of the structure, such defects need not be repaired or rewelded, provided that, for any such defect, such methods of assessment are acceptable to both the principal and the fabricator. Repaired welds shall be reinspected to the same level as that originally specified. NOTES: 1 WTIA Technical Note 10 gives guidance on the use of fracture mechanics analyses in the assessment of the effects of imperfections. 2 Imperfections of plate origin are not normally considered to be a cause for rejection of the weld. 6.8 REPORTING


Test reports for non-destructive examination shall comply with the appropriate Standard and shall include the following additional information: (a)

Identity and qualification of testing personnel.

(b)

A statement whether the weld complies with the requirements of this Section. If the weld does not comply, the location, type and extent of imperfections.

(c)

The type and method of examination carried out.

(d)

Results of re-examinations.

All reports, including calculations for fracture mechanics assessments of defective welds, shall be retained and made available for information purposes. NOTE:Test reports that may be used for revalidation or prolongation of welder qualification should include WPS number, date welded and welder ID.

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S E C T I O N

7

I N S P E C T I ON

7.1 GENERAL This Section shall apply only to inspection by the inspecting authority or the principal. The inspector shall have access at all reasonable times to all relevant phases of the work, and shall be given reasonable notice in advance of the start of welding operations. The inspector shall have the opportunity to witness all testing of welding procedures and welder qualification tests that are required. 7.2 QUALIFICATIONS OF INSPECTORS


The inspector shall have had suitable training and experience in the fabrication and inspection of welded structures. The holding of one of the following shall be accepted as evidence of these qualifications: (a)

International Institute of Welding diploma as an IIW Welding Inspector, at the appropriate level.

(b)

A Welding Technology Institute of Australia Certificate as a Welding Inspector, at the appropriate level.

(c)

A Certification Board of Inspection Personnel (CBIP) New Zealand Welding Inspector.

(d)

A certificate as a structural welding supervisor in accordance with AS 2214.

(e) Have other qualifications and experience acceptable to the principal. NOTES: 1 The inspector should have at least the qualifications required for a welding supervisor. 2 The inspector should be certified as competent to inspect at the level required by the principal or inspecting authority. 3 The inspector should not be involved in the supervision of the welded fabrication. 7.3 VISUAL INSPECTION OF WORK Prior to and during welding, the inspector should inspect the set-up of the work and be satisfied that— (a)

welds are in accordance with the drawings;

(b)

the welding is carried out on the specified material with suitable equipment;

(c)

correct procedures are maintained; and

(d)

the work is performed in accordance with the requirements of this Standard.

The inspector shall make a careful and systematic check to ensure that no welds called for in the drawings are omitted. All welds shall receive a full visual inspection in accordance with Section 6 and AS 3978. Aids to visual examination may be used wherever necessary to facilitate the assessment of an imperfection. Inspection aids and measuring devices shall be sufficient to enable the inspector to detect imperfections that could occur on welds.

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7.4 NON-DESTRUCTIVE EXAMINATION OTHER THAN VISUAL Personnel responsible for the interpretation, evaluation and reporting of non-destructive examination shall have qualifications and experience acceptable to the inspecting authority and the principal. Personnel holding appropriate certification in accordance with AS 3998 to level 2 or the CBIP-NZ shall be deemed to be qualified. Where non-destructive examination is specified, the drawings or other documents shall clearly state the methods to be used, and the extent of testing to be carried out (also see Clause 3.1.2). NOTE: Further guidance as to the extent of non-destructive examination is given in Table 7.4. TABLE 7.4 SUGGESTED EXTENT OF NON-DESTRUCTIVE EXAMINATION Extent of NDE, percent Visual means (see Note)


Weld category

Other means

Visual scanning (see Clause 7.3)

Visual examination to Table 6.3.2

Liquid penetrant

Radiography or ultrasonics to Table 6.3.1(A) and 6.3.1(B)

1A

100

100

100

0 to 25

1B

100

10 to 50

0 to 2

0 to 10

1C

100

0 to 25

0 to 2

Nil

2A

100

10 to 50

0 to 10

Nil

2B

100

10 to 50

0 to 5

Nil

2C

100

0 to 25

0 to 2

Nil

FA

100

100

0 to 2

0 to 10

NOTE: Visual means of NDE implies two levels of examination as follows: (a)

Visual scanning—to determine that no welds called for in the drawings are omitted and to detect gross defects.

(b)

Visual examination—to examine a percentage of the welds to determine whether the required weld quality (see Table 6.3.2) has been achieved.

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APPENDIX A

NORMATIVE REFERENCES (Normative)


AS 1470

Health and safety at work—Principles and practices

1674 1674.1 1674.2

Safety in welding and allied processes Part 1: Fire precautions Part 2: Electrical

1796

Certification of welders and welding supervisors

1966 1966.1 1966.2

Electric arc welding power sources Part 1: Transformer type Part 2: Rotary type

2062

Non-destructive testing—Penetrant testing of products and components

2177

Non-destructive testing—Radiography of welded butt joints in metal

2177.1

Part 1: Methods of test

2177.2

Part 2: Image quality indicators (IQI) and recommendations for their use

2205 2205.2.1 2205.3.1 2205.3.3. 2205.5.1

Methods of destructive testing of welds in metal Method 2.1: Transverse butt tensile test Method 3.1: Transverse guided bend test Method 3.3: Longitudinal guided bend test Method 5.1: Macro metallographic test for cross-section examination

2214

Certification of welding supervisors—Structural steel welding

2382

Surface roughness comparison specimens

2799

Resistance welding equipment—Single-phase a.c. transformer type

2812

Welding, brazing and cutting of metals—Glossary of terms

2865

Confined spaces

3978

Non-destructive testing—Visual inspection of metal products and components

3998

Non-destructive testing—Qualification and certification of personnel

4100

Steel Structures

4882

Shielding gases for welding

60974 60974.1

Arc welding equipment Part 1: Welding power sources (IEC 60974-1:2000, MOD)

AS/NZS 1167 1167.2

Welding and brazing—Filler metals Part 2: Filler metal for welding

1336

Recommended practices for occupational eye protection

1337

Personal eye protection

1337.1

Part 1: Eye and face protectors for occupational applications

1338

Filters for eye protectors

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1338.1

Part 1: Filters for protection against radiation generated in welding and allied operations

1995

Welding cables

2980

Qualification of welders for fusion welding of steels

3992

Pressure equipment—Welding and brazing qualification

4854

Welding consumables—Covered electrodes for manual metal arc welding of stainless and heat-resisting steels—Classification

ISO 8249


AS/NZS 1554.6:2012

Welding—Determination of Ferrite Number (FN) in austenitic and duplex ferritic-austenitic Cr-Ni stainless steel weld metals

9606

Approval testing of welders—Fusion welding

9606-1

Part 1: Steels

14174

Welding consumables—Fluxes for submerged arc welding—Classification

14731

Welding coordination—Tasks and responsibilities

15730

Metallic and other inorganic coatings—Electropolishing as a means of smoothing and passivating stainless steel

22825

Non-destructive testing of welds—Ultrasonic testing—Testing of welds in austenitic steels and nickel-based alloys

ANSI/AWS A4.2 Standard procedures for calibrating magnetic instruments to measure the delta ferrite content of austenitic and duplex austenitic-ferritic steel weld metal A5.22

Specification for flux cored corrosion-resisting chromium and chromium-nickel steel electrodes

A5.4

Specification for covered corrosion-resisting chromium and chromium-nickel steel welding electrodes

A5.9

Specification for corrosion-resisting chromium and chromium-nickel steel bare and composite metal cored and stranded welding electrodes and welding rods

D18.2

Guide to Weld Discoloration Levels on Inside of Austenitic Stainless Steel Tube

ASTM A380 B912

Standard practice for cleaning, descaling, and passivation of stainless steel parts, equipment, and systems Standard specification for passivation of stainless steels using electropolishing

AS/NZS ISO 3834 Quality requirements for fusion welding of metallic materials (all parts) 14343

Welding consumables—Wire electrodes, wires and rods for arc welding of stainless and heat-resisting steels—Classification

17633

Welding consumables—Tubular cored electrodes and rods for gas shielded and non-gas shielded metal arc welding of stainless and heat-resisting steels— Classification (ISO 17633:2004, MOD)

AS ISO 13916

Welding—Guide on the measurement of preheating temperature, interpass temperature and preheat maintenance temperature

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NZS 3404 3404.1 3404.2

Steel structures Standard Part 1 Materials, fabrication, and construction Part 2 Structural analysis

ASME B46.1

Surface Texture (Surface Roughness, Waviness, And Lay)

Section IX

ASME Boiler and Pressure Vessel Code


WRC Stainless Steel Weld Metal—Prediction of Ferrite Content Bulletin 519

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APPENDIX B

SELECTION OF WELD CATEGORY AND SURFACE FINISH (Informative) B1 GENERAL This Appendix gives guidance on the selection of the appropriate weld category and surface finish for obtaining structural integrity, corrosion resistance, hygiene and aesthetics suitable for the intended application. B2 SUB-SURFACE (INTERNAL) QUALITY Category 1 is generally selected for structural and load bearing joints, e.g. hoppers, tanks and pipework, and for welds subject to moderate level of dynamic (fatigue) loading.


Category 2 is intended where structural integrity is not paramount, e.g. architectural fascias, decorative handrails and benchtops. Category 2 is not subject to internal examination. Category F is selected for high level dynamic (fatigue) loading where detail categories greater than 112 of AS 4100 is applicable, e.g. machinery parts. B3 SURFACE (EXTERNAL) WELD QUALITY B3.1 General Three classes of external weldment imperfections are provided. Selection will depend primarily on the level of corrosion resistance, hygiene or fatigue resistance required of a particular application. Classes A and B normally require additional surface finishing (see Paragraph B4). B3.2 Class A Class A offers the highest level of surface quality and is normally only selected for the most demanding applications, such as structural parts exposed to severe fatigue loading, and the special hygiene requirements of serum laboratories and chemical reaction tanks where final surface finish is critical to ensure the product does not bind to surface irregularities. B3.3 Class B Class B is generally selected for most corrosion applications. Class B is also suitable for finishing as decorative handrails, benchtops and hygiene applications such as food and beverage processing equipment. Some aesthetically critical applications, may not permit crevices in drainage paths and may require tighter specification. B3.4 Class C Class C is provided for all non-critical surfaces. These surfaces are generally not exposed to corrosive media or food products, nor are they visually important, e.g. internal weld surfaces of handrails, and external welds of tanks, hoppers, ductwork and structural supports where low stresses and only mild corrosive media are present. B4 SURFACE CONDITION B4.1 General Three grades of surface finish are provided and should be specified in order to maintain corrosion integrity of the material, aesthetics, hygiene or fatigue performance.

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B4.2 Surface condition I—Polished Typically decorative applications, high stress fatigue applications and food processing equipment may require a specified finish, e.g. 0.2 – 0.4µm Ra. B4.3 Surface condition II—Cleaned This grade is intended to provide the best possible corrosion resistance of a welded joint that is not subsequently mechanically polished, by cleaning off the dark weld oxide and promoting formation of the protective chromium oxide (see Clause 6.2.6). The welded zone produced by automatic welding processes such as PAW and TIG can be left as-welded where the weld and heat affected zone have a low degree of oxidation complying with the Table 6.3.3. B4.4 Surface condition III—As-welded The as-welded condition should only be specified for non-critical surfaces that are not exposed to any corrosive media or food product, and for which appearance is unimportant, e.g. inside handrails, external welds on ductwork, and internal surfaces of structural parts.


B5 SURFACE ROUGHNESS The average roughness Ra is the most commonly used parameter in surface finish measurement. Graphically, the average roughness is the area between the roughness profile and its ulphur ne divided by the evaluation length. Ra is insensitive to extreme profile peaks and valleys. Therefore, the maximum roughness depth may be represented by the R max value. Rmax value can be specified by the principal in addition to Ra. The most universal technique is to measure surface roughness with a stylus contact-type instrument that provides a numerical value for surface roughness according to ASME B46.1. The average roughness Ra is determined by measurements across and along the weld. The measurements have to be performed at the worst section of the weld distinguished by the visual inspection. The surface roughness required in the applicable Standards, such as ASME BPE, ASME B31.3 or MAF NZCP 6, is normally achieved by grinding and polishing the welds. Traditionally mechanically polished surfaces have been described by the grit size of the final polishing belt, such as "120 grit" or "120#". This widespread convention can be very imprecise as it takes no account of factors such as the polishing pressure, the type of abrasive (silicon carbide, aluminium oxide etc), whether the polish was carried out with or without lubricant, whether the belt was new or nearing the end of its life. A quantified Ra value or agreement to visually match samples is preferable as these designate a polished finish that can be confirmed by subsequent inspection.

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B6 EXAMPLES In order to provide a guide as to how the weld categories and surface finishes combine to give a fully specified weld, the following examples are given: EXAMPLE 1: Chemical acid tank Internal External Surface quality quality condition Internal surface in contact with acid

1

B

II(a)

External surface in air at ambient conditions

1

C

II(d)

Recommended notation on specification or on drawing: (i)

Internal welds 1B, II(a)

(ii)

External welds 1C, II(d)

EXAMPLE 2: Rotating screen for water treatment applications (high level of fatigue) Internal External Surface quality quality condition Accessed by BUREAU VERITAS AUSTRALIA PTY LTD on 27 Mar 2013 (Document currency not guaranteed when printed)

Butt weld

F

A

II(a)

Recommended notation on specification or on drawing: FA, II(a) EXAMPLE 3: Decorative handrail; 120# grit polish Internal External Surface quality quality condition Internal surface

2

C

III

External surface

2

B

I 120#

Recommended notation on specification or on drawings: (i)

Internal welds 2C, III

(ii)

External welds 2B, I (0.2–0.5µm Ra)

NOTE: In fatigue applications other than FA welds, grade I surface finish should always be used in conjunction with external weld quality A to give the desired result

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AS/NZS 1554.6:2012

80

APPENDIX C

TYPICAL FORMS FOR WELDING PROCEDURES (Informative)


This Appendix provides typical forms for the procedure qualification record (PQR) and welding procedure specification (WPS).

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AS/NZS 1554.6:2012


81

PROCEDURE QUALIFICATION RECORD Material spec/grade To Weld category Surface finish Fabricator PQR No. Process Date qualified Welding Standard Welded by Edge preparation Page Specimen thickness Revision Date Qualified position Preheat temperature PWHT Inter-run temperature Hold Type and check method Other Run sequence Joint details Prequal. Joint No. To table Root gap G mm Root face Fr mm Incl. angle θ° Backing Flux Specification—Root Remainder Classification—Root Remainder Shielding gas Flow rate Purge gas Flow rate Weld run details Welding parameters No. Side Position φ mm Trade Welding Wire feed Arc Current Travel name current, speed, voltage, and speed (A) m/min (V) polarity mm/min

Technique Initial cleaning Inter-run clean Nozzle size Cleaning and passivation treatment Test Visual type Test by Report no. Result Material certificate number: Notes/revisions

Witnessed by

Macro

Heat input kJ/mm

Stringer/weave Electrical stick out Backgouge method Backgouge check

Tensile

Test results Bend

Charpy V

Consumable test certificate number:

Approved by

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Hardness

Other

AS/NZS 1554.6:2012

82

WELDING PROCEDURE SPECIFICATION Material specification/grade

to

Weld category

Surface finish

Fabricator

WPS No.

Standard

Date

Process

PQR No.

Edge preparation

Page

Welding direction

Revision

Range qualified

Positions

Preheat temperature

PWHT

Method and check method

Hold

Inter-run temperature (max.)

Other

Joint sketch

Run sequence

Date

Joint tolerance Pre-qualified joint No. To table


Root gap G mm Root face Fr mm Included angle θ° Backing Welding consumables Specification—Root

Remainder

Classification—Root

Remainder

Shielding gas

Flow rate

Purge gas

Flow rate

Flux

Weld run details Pass no.

Side

Position

φ mm

Welding parameters Trade name

Welding current range, (A)

Wire feed speed range m/min

Technique

Stringer/weave

Single-run or multi-run

Electrical stick out

Initial cleaning

Backgouge method

Inter-run clean

Backgouge check

Cleaning and passivation treatment Notes/revisions Approved by COPYRIGHT

Arc voltage range, (V)

Current and polarity

Travel speed range mm/min

Heat input range, kJ/mm

83

AS/NZS 1554.6:2012

APPENDIX D

WELDED JOINT AND PROCESS IDENTIFICATION (Normative) D1 NOTATION FOR JOINT IDENTIFICATION The notation used for joint identification in the first column of Tables D1 to D4 is the following:


W

X

Y

z

= joint type identification, as follows: B

= butt joint

C

= corner joint

F

= fillet joint

H

= joint for hollow sections to AS 1163 and AS 1450

T

= T joint

= penetration identification, as follows: C

= complete penetration

P

= part (incomplete) penetration

= preparation identification, as follows: 1

= square

2

= single-V

3

= double-V

4

= single-bevel

5

= double-bevel

6

= single-U

7

= double-U

8

= single-J

9

= double-J

= a, b, c or d, to distinguish between diagrams showing variations of the same prequalified joint.

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AS/NZS 1554.6:2012

84

D2 NOTATION FOR DIMENSIONS, POSITIONS AND BACKING MATERIAL The notation used for dimensions, positions and backing material in Tables D1 to D4 is the following: D

= depth of preparation, in millimetres


DTT = design throat thickness, in millimetres F

= flat position

Fr

= width of root face, in millimetres

G

= width of root gap, in millimetres

H

= horizontal position

OH

= overhead position

R

= root radius (the point from which the radius is generated lies on a line projected from the root face), in millimetres

S

= size of weld, in millimetres

S′

= apparent size of weld, in millimetres

t

= plate thickness, in millimetres

V

= vertical position

X

= depth of one preparation in a double-V butt weld, in millimetres

θ

= included angle of preparation, in degrees.

D3 NOTATION FOR PROCESSES The notation used for welding processes is the following: FCAW(C or M)

= flux cored arc welding with gas shielding, where C indicates shielding with carbon dioxide and M indicates shielding with mixed gases

FCAW(N)

= flux cored arc welding without gas shielding, where N indicates no gas shielding

GMAW

= gas metal arc welding, also known as MIG

GTAW

= gas tungsten arc welding, also known as TIG

MMAW

= manual metal-arc welding

SAW

= submerged arc welding

D4 EXAMPLE A square corner joint complete penetration butt weld, welded both sides using submerged arc welding, can be described as C-C 1c–SAW.

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TABLE D1 PREQUALIFIED COMPLETE PENETRATION BUTT WELD PREPARATIONS NOTES: 1

The notation used is given in Paragraphs D1 to D3.

2

For dimensional tolerances of weld preparations, see Table 5.7.2.

3

All linear dimensions are in millimetres.

4

For details of gouging the roots of the weld, see Clause 4.5.2.

5

These joints may not be suitable for some corrosion applications. The approval of the principal should therefore be sought.

6

Gas-shielded metal-arc spray transfer includes pulsed mode.

7

Gas-shielded metal-arc dip transfer includes controlled dip mode.

B-C 1a

Preparation detail

Joint type

Close-square butt weld, welded both sides

t

Manual metal-arc

3 max.

Submerged arc

Flux-cored arc self-shielded and gasshielded

Gas-shielded metal-arc spray transfer (see Note 6)

Gas-shielded metal-arc dip transfer (see Note 7)

Gastungsten arc

12 max.

6 max.

6 max.

—

3 max.

Position

All

F

F

F

—

All

G

0

0

0

0

—

0

t

6 max.

—

10 max.

—

6 max.

6 max.

Position

All

—

All

—

All

All

G

t/2

—

t/4

—

t/2

t/2

85

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Joint identification (see Note 4)

t G

B-C 1b

Open-square butt weld, welded both sides

(continued)

AS/NZS 1554.6:2012

t G


Joint type

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

Open-square butt weld and corner joint, welded one side with backing strip (see Note 5)

t

6 max.

12 max.

12 max.

12 max.

10 max.

—

Position

All

F

All

F

All

—

G

t

t/2

t

t/2

3t/2

—

t

6 max.

—

6 max.

—

6 max.

6 max.

Position

All

—

All

—

All

All

G

t/2

—

t/4

—

3

t/2

t

3

10 max.

6 max.

6 max.

—

3 max.

Position

All

F

F

F

—

All

G

0

0

0

0

—

0

Joint identification (see Note 4) B-C 1c C-C 1a

*

AS/NZS 1554.6:2012

TABLE D1 (continued)

t G

* M or MR

Open-square T and corner joint, welded both sides

t G

C-C 1c T-C 1b

Square-T and corner joint, butt welded both sides

t G

(continued)

86

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T-C 1a C-C 1b


TABLE D1 (continued) Joint identification (see Note 4) B-C 2a C-C 2a

Joint type

Single-V butt weld and corner joint, welded both sides

Fr

t

G

Single-V butt weld and corner joint, welded one side with backing strip (see Note 5) *

Manual metal-arc

Submerged arc




Gastungsten arc

t

All

All

All

All

All

20 max.

Position

All

F

See θ

F

See θ

All

G

3.5

0

3

0

3

3

Fr

1.5

6

3

4

0

1.5

θ

60

60

50 for F, H, OH 60 for V

50


60

t

All

All

All

All

All

—

Position

See θ

F

See θ

F

See θ

—

G

See θ

See θ

6

3

6

—

Fr

0

0

0

1.5

0

—

θ

20 for F, OH: G = 2 30 for F, OH: G = 9 45 for All: G = 6

30: G = 6 20: G = 15


30


—

87

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B-C 2b C-C 2b

Preparation detail

Fr t G

* M or MR

AS/NZS 1554.6:2012

(continued)


Joint identification (see Note 4) B-C 2c

Manual metal-arc

Submerged arc




Gastungsten arc

t

20 max.

—

20 max.

20 max.

20 max.

—

Position

H

—

H

H

H

—

G

5 to 8

—

5 to 8

5 to 8

5 to 8

—

Fr

0

—

0

0

0

—

θ1

45

—

45

45

45

—

θ2

15

—

15

15

15

—

Single-V butt weld, welded both sides (see Note 5)

t

32 max.

32 max.

32 max.

32 max.

32 max.

20 max.

Back gouge to sound metal before welding second side

Position

All

F

All

All

All

All

G

0

0

0

0

0

0

Fr

t/3 max.

≥ 6 ≤ t/3

t/3 max.

t/3 max.

t/3 max.

t/3 max.

θ1

60

60

60

60

60

60

Joint type

Single-V butt weld, welded one side with backing (see Note 5) t

*

G

Fr COPYRIGHT

* M or MR

B-C 2d

88

Preparation detail

Back gouge t G

Fr

B a c k g o u g e to s o u n d m e t a l b efo r e we l di n g second side

AS/NZS 1554.6:2012


(continued)


TABLE D1 (continued) Manual metal-arc

Submerged arc




Gastungsten arc

B-C 3

Double-V butt weld, welded both sides

t

All

All

All

All

All

20 max.

NOTE: Depth X may range from ⅔(t – F r ) to ⅓(t – F r )

Position

All

F

See θ

F

See θ

All

G

3.5

0

3

0

4

3

Fr

1.5

6

3

3

0

1.5

θ

60

60


50


60

t

All

All

All

All

All

20 max.

Position

All

F and H

See θ

F and H

See θ

All

G

3.5

0

3

1.5

4

3

Fr

1.5

6

1.5

4

0

1.5

θ

45

60


50


60

Fr

x

t COPYRIGHT

G

B-C 4a T-C 4a C-C 4a

Single-bevel butt weld, T and corner joint, butt welded both sides L owe r e d g e fo r h o r izo nt a l p o s i ti o n

*

t G

89

Joint type

Preparation detail


(a) * t G

(continued)

AS/NZS 1554.6:2012

* M o r M R ( b)


Joint identification (see Note 4) B-C 4b T-C 4b C-C 4b

Joint type

Single-bevel butt weld, T and corner joint, butt welded one side with backing strip (see Note 5)

L owe r e d g e fo r h o r izo nt a l p o s i ti o n

*

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

t

All

All

All

All

All

—

Position

See θ

F and H

See θ

F and H

See θ

—

G

See θ

See θ

See θ

5

See θ

—

Fr

0

0

0

0

0

—

θ

20 for F, G = 11 mm (B for C 4b only) 30 for F, G = 9 mm 45 for All; G = 6 mm

30: G = 10 45: G = 6

30 for F: G = 10 45 for V, H OH: G = 6

30 for F and H

30 for F 45 for V, H, OH

—

AS/NZS 1554.6:2012


t

(a)

90

COPYRIGHT

G

* t G

* M o r M R ( b)

(continued)


TABLE D1 (continued) Joint identification (see Note 4) B-C 5 T-C 5 C-C 5

Joint type

Double-bevel butt weld, T and corner joint

Fr

t

G

Single-U butt weld and corner joint, welded both sides

R G

t Fr

Manual metal-arc

Submerged arc




Gastungsten arc

t

All

All

All

All

All

20 max.

Position

All

F

See θ

F

See θ

All

G

3.5

0

1.5

0

4

3

Fr

1.5

6

1.5

3

0

1.5

θ

45

60


50

50 for F, H, OH, 60 for V

60

t

All

All

All

All

All

All

Position

See θ

F

All

F

All

All

G

1.5

0

1.5

0

4

1.5

Fr

1.5

6

1.5

3

0

1.5

R

6

8

8

8

8

6

θ

30 for F and OH 45 for All

20

30

30

30

45

91

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B-C 6a C-C 6a

Preparation detail

AS/NZS 1554.6:2012

(continued)


Joint identification (see Note 4) B-C 6b C-C 6b

Joint type

Single-U butt weld and corner joint, welded one side with backing strip (see Note 5) *

R

Submerged arc




Gastungsten arc

t

All

All

All

All

All

—

Position

See θ

F

All

F

All

—

G

7

2

6

3

6

—

Fr

1.5

1.5

0

1.5

0

—

R

6

8

8

8

8

—

θ


20

30

30

30

—

t

All

All

All

All

All

All

Position

See θ

F

All

F

All

All

G

1.5

0

1.5

0

4

1.5

Fr

1.5

6

3

3

0

1.5

R

6

8

8

8

8

6

θ

30 for F, and OH 45 for All

20

30

30

30

45

Fr

* M or MR

Double-U butt weld, welded both sides

R

92

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Manual metal-arc

t

G

B-C 7

Preparation detail

t R G

AS/NZS 1554.6:2012


Fr

(continued)


TABLE D1 (continued) Joint identification (see Note 4) B-C 8a T-C 8a C-C 8a

Joint type

Single-J butt weld and corner joint, welded both sides

R

t

Fr

G

Single-J butt weld and corner joint, welded one side with backing strip (see Note 5) *

Manual metal-arc

Submerged arc




Gastungsten arc

t

All

All

All

All

All

All

Position

See θ

F: MMAW or SAW weld on second side

All

F and H

All

All

G

1.5

0

3

1.5

4

1.5

Fr

1.5

6

3

4

0

1.5

R

6

See θ

See θ

8

8

6

θ


30: R = 12 45: R = 6

30: R = 10

45

45

45

t

All

—

All

All

20 max.

—

Position

See θ

—

All

F

All

—

G

7

—

6

3

6

—

Fr

1.5

—

0

3

0

—

R

6

—

6

6

6

—

θ


—

45

45

45

—

45: R = 6

93

COPYRIGHT

B-C 8b T-C 8b C-C 8b

Preparation detail

t Fr

G (a) *

t

* M o r M R ( b)

(continued)

AS/NZS 1554.6:2012

G


Joint identification (see Note 4) B-C 9 T-C 9 C-C 9

Joint type

Double-J butt weld, T and corner joint

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

t

All

All

All

All

All

All

Position

See θ

F: MMAW or SAW weld on second side

All

F and H

All

All

G

1.5

0

3

0

4

1.5

Fr

1.5

6

3

4

0

1.5

R

6

See θ

6

8

8

6

θ


30: R = 12 45: R = 6

45

45

45

45

AS/NZS 1554.6:2012


R t G

R

Fr

94

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TABLE D2 PREQUALIFIED INCOMPLETE PENETRATION BUTT WELD PREPARATIONS NOTES: 1


2

For dimensional tolerances of weld preparations, see Table 5.7.2.

3

For increased DTT for fully automatic process see Clause 3.2.2.

4


5


6


7


B-P 1a

Joint type

Close-square butt weld, welded one side (see Note 5)

t G

B-P 1b

Open-square butt weld, welded one side (see Note 5)

t

Manual metal-arc

Submerged arc




Gastungsten arc

t

3 max.

6 max.

4 max.

3 max.

3 max.

—

Position

All

F

F and H

F and H

All

—

G

0

0

0

0

0

—

DTT

0.75t

0.75t

0.75t

0.75t

t/2

—

t

6 max.

—

8 max.

6 max.

6 max.

—

Position

All

—

F and H

F and H

All

—

G

t/2

—

t/4

t/4

t/2

—

DTT

0.75t

—

0.75t

0.75t

t/2

— (continued)

AS/NZS 1554.6:2012

G

Preparation detail

95

COPYRIGHT



Joint identification (see Note 4) B-P 2a C-P 2

Manual metal-arc

Submerged arc




Gastungsten arc

Single-V butt weld and corner joint, welded one side (see Note 5)

t

All

All

All

All

All

—

Position

All

F

See θ

F

See θ

—

G

0

0

0

0

0

—

θ

45: DTT = D – 3 60: DTT = D

60


50


—

DDT

See θ

D

D−3

D−3

D−3

—

t

All

All

All

All

All

20 max.

Position

All

F

See θ

F

See θ

All

G

0

0

0

0

0

0

θ

45, 60

60


50


70

DTT

45: (D 1 + D 2 ) – 6 60: D 1 + D 2

D1 + D2

(D 1 + D 2 ) − 6

(D 1 + D 2 ) − 6

(D 1 + D 2 ) − 6

D1 + D2

t D

COPYRIGHT

B-P 3

Double-V butt weld, welded both sides

D1 t

D2 G

(continued)

96

Joint type

Preparation detail

AS/NZS 1554.6:2012



TABLE D2 (continued) Joint identification (see Note 4) B-P 4a C-P 4

Joint type

Single-bevel butt weld, T and corner joint, welded one side (see Note 5)

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

t

All

All

All

All

All

—

Position

All

F and H

All

F and H

All

—

G

0

0

0

0

0

—

θ

45

60

45

45

45

—

DDT

D−3

D

D−3

D−3

D−3

—

t

All

All

All

All

All

20 max.

Position

All

F

All

F and H

All

All

G

0

0

0

0

0

0

θ

45

60

45

45

45

60

DTT

(D 1 + D 2 ) − 6

D1 + D2

(D 1 + D 2 ) − 6

(D 1 + D 2 ) − 6

(D 1 + D 2 ) − 6

(D 1 + D 2 ) − 6

t

All

All

All

All

All

—

Position

All

F

All

F and H

All

—

G

1.5

0

0

0

0

—

R

6

6

6

6

6

—

θ

45

20

30

30

30

—

DTT

D

D

D

D

D

—

T-P 4 t G

B-P 5

C-P 5 D1

97

COPYRIGHT

T-P 5

Double-bevel butt weld, T and corner joint

t

D2

B-P 6 C-P 6

Single-U butt weld and corner joint, welded one side (see Note 5)

D

R

(continued)

AS/NZS 1554.6:2012

G

t


Joint identification (see Note 4) B-P 7

Joint type

Double-U butt weld, welded both sides

D1

R

t

D2

R

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

t

All

All

All

All

All

All

Position

All

F

All

F and H

All

All

G

1.5

0

0

0

0

0

R

6

6

6

6

6

6

θ

45

20

30

30

30

45

DTT

D1 + D2

D1 + D2

D1 + D2

D1 + D2

D1 + D2

D1 + D2

t

All

All

All

All

All

—

Position

All

F

All

F and H

All

—

G

1.5

0

0

0

0

—

R

10

12

10

10

10

—

θ

45

20: B and C joint 45: T joint

45

45

45

DTT

D

D

D

D

D

AS/NZS 1554.6:2012


G

T-P 8

Single-butt weld, T and C joint welded one side (see Note 5)

C-P 8

R G

98

COPYRIGHT

B-P 8

t D

— — (continued)


TABLE D2 (continued) Joint identification (see Note 4) B-P 9 C-P 9

Joint type

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

Double-J butt weld T and C joint, welded both sides

t

All

All

All

All

All

All

Position

All

F

All

F and H

All

All

G

1.5

0

0

0

0

0

R

10

12

10

10

10

10

θ

45

20: B and C joint

45

45

45

45

DTT

D1 + D2

D1 + D2

D1 + D2

D1 + D2

D1 + D2

D1 + D2

C-P 9

R

D1

R

D2

99

COPYRIGHT

G

t

AS/NZS 1554.6:2012


AS/NZS 1554.6:2012

TABLE D3 PREQUALIFIED PREPARATIONS FOR FILLET WELDS LEGEND:

t

=

plate thickness

S

=

Size of weld

θ

=

included angle of preparation, in degrees

G

=

root gap

DTT

=

design throat thickness

NOTES: 1


2

For increased DTT for fully automatic processes, see Clause 3.3.2.

3


4

These joints may not be suitable for corrosion applications. The approval of the principal should therefore be sought.

Joint type (see Note 4)

F1

Fu s i o n fa c e

TT

S

D

Leg

Joint description Fillet weld with equal leg size and no root gap; for gap tolerances, see Clause 5.7.3

90˚ S Leg

DTT 100

COPYRIGHT


S 2

θ = 90

(continued)


TABLE D3 (continued) F2

Fillet weld with root gap

S-G

S

θ = 90

DT T 90˚

G

(S − G ) 2

S

Fillet weld with unequal leg sizes 90˚

θ = 90

(S

2 1

S1S 2 + S 22

)

V2

101

COPYRIGHT

DT

S2

T

F3

S1

F4 1 mm see Clause 3. 3.6 t S

D

TT

Lap joint with unfused edge—applicable for t ≥ 6 mm

90˚

S 2

θ = 90

(continued) AS/NZS 1554.6:2012


AS/NZS 1554.6:2012

TABLE D3 (continued) F5 A p p a r e nt s ize

t

Pl ate e d g e b u r nt away

S

D

TT

Lap joint with unfused edge—applicable for t < 6 mm

90˚

S 2

θ = 90

F6 S t

D

TT

B u il t o u t h e r e to e n s u r e n o d e f i c i e n cy of s i ze a n d t h r o a t

Lap joint with built-up edge—applicable to all thickness

θ = 90

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90˚

S 2

(continued)


TABLE D3 (continued) F7 t

DT T1

Skewed T-joint with no root gap, welded both sides

DT T 2

S1

90˚

90˚ S1

= S1 cos S2

S2

θ = 60 to 90

F8 DT T2

S1 G

90˚

90˚ S2

S2

Skewed T-joint with root gap, welded both sides

θ = 60 to 90

=

S12 sin θ 2 ⎡⎛ ⎤ G ⎞ 2 + S1 cos θ ⎟ + (G + S1 sin θ ) ⎥ ⎢⎜ S 1+ tan θ ⎠ ⎣⎢⎝ ⎦⎥

+

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S1

180 − θ θ S 2 cos 2 2

DTT = DTT1 + DTT2

t

DT T1

DTT = DTT1 + DTT2

S 22 sin θ 2 ⎡⎛ ⎤ G ⎞ 2 S − − S cos θ ⎟ + (G + S 2 sin θ ) ⎥ ⎢⎜ 2 2 tan θ ⎠ ⎢⎣⎝ ⎥⎦

(continued)

AS/NZS 1554.6:2012


AS/NZS 1554.6:2012

TABLE D4 PREQUALIFIED COMPLETE PENETRATION BUTT WELD PREPARATIONS FOR HOLLOW SECTIONS WELDED FROM ONE SIDE NOTES: 1


2

For dimensional tolerances of weld preparations, see Table 5.7.2, except where different tolerances are given in this Table in which case the values given in this Table apply.

3

For increased DTT for fully automatic process is Clause 3.2.2.

4


5


6


7


Manual metal-arc

Submerged arc




Gastungsten arc

H-C 1a

Square butt weld, welded one side without backing

t

3 max.

—

—

—

3 max.

3 max

Position

All

—

—

—

All

All

G

1.5

—

—

—

1.5

1.5

t G

(continued)

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Joint type

Preparation detail



TABLE D4 (continued) Joint identification (see Note 4) H-C 1b

Joint type

Square butt weld, welded one side with backing (see Note 5)

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

t

6 max.

12 max.

12 max.

12 max.

10 max.

—

Position

All

F

All

F

All

—

G

t

t/2

t

t/2

1.5t

—

t

20 max.

—

—

—

20 max.

20 max.

Position

All

—

—

—

All

All

G

1 to 3

—

—

—

1 to 3

2 to 3

Fr

1 to 2.5

—

—

—

0

0

θ

60

—

—

—

60

60

* t G * M or MR

H-C 2a

Fr G

t

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Single-V butt weld, welded one side without sealing run and without backing

(continued)

AS/NZS 1554.6:2012


Joint identification (see Note 4) H-C 2b

Joint type

Single-V butt weld, welded one side with backing (see Note 5) * Fr

t

G

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

t

All

All

All

All

All

—

Position

All

F

All

F

All

—

G

5 to 8

See θ

5 to 8

5 to 8

5 to 8

—

Fr

0

0

0

0

0

—

θ

60

30: G = 6 20: G = 15

60

60

60

—

t

20 max.

—

20 max.

20 max.

20 max.

—

—

—

—

—

—

—

—

Position

H

—

H

H

H

—

G

5 to 8

—

5 to 8

5 to 8

5 to 8

—

Fr

0

—

0

0

0

—

θ1

45

—

45

45

45

—

θ2

15

—

15

15

15

—

AS/NZS 1554.6:2012


* M or MR

Single-V butt weld, welded one side with backing (see Note 5) t

* G

Fr * M or MR

(continued)

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H-C 2c


Joint identification (see Note 4) H-C 4a

Joint type

Single-bevel butt weld, welded one side without sealing run and without backing (see Note 5)

t G

Fr

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

t

20 max.

—

—

—

20 max.

—

Position

All

—

—

—

All

—

G

2 to 4

—

—

—

2 to 4

—

Fr

1 to 3

—

—

—

0

—

θ

45

—

—

—

45

—

DRAFT ONLY


(continued) 107 DRAFT ONLY


Joint type

Preparation detail

Manual metal-arc

Submerged arc




Gastungsten arc

Single-bevel butt weld, welded one side with backing (see Note 5)

t

All

—

All

All

All

—

Position

All

—

All

F and H

All

—

G

6

—

6

6

6

—

Fr

0

—

0

0

0

—

θ

45

—

45

45

45

—

t

20 max.

—

20 max.

20 max.

20 max.

—

Position

All

—

All

F

All

—

β

45 min.

—

45 min.

45 min.

45 min.

—

G

2 to 5

2 to 5

2 to 5

2 to 5

(at toe)

0 for β > 90

0 for β > 90

0 for β > 90

0 for β > 90

α = 15 to

α = 15 to

α = 15 to

20: G = 12

20: G = 12

25: G = 5

α = 20 to

α = 20 to

α = 25 to

25: G = 9

25: G = 9

40: G = 3

α = 25 to

α = 25 to

30: G = 6

30: G = 6

α = 30 to

α = 30 to

40: G = 3

40: G = 3

Joint identification (see Note 4) H-C 4b

*

AS/NZS 1554.6:2012


t

Fr G * M or MR

H-C 4c

t

G G1 Fr (a) Pr of il e fo r a to e

—

α = 15 to 25: G = 5

—

—

α = 25 to 40: G = 3

—

—

α > 40: G = 2

—

—

—

—

Fr

0 to 1

—

0 to 1

θ

30 min

—

30 min.

(at crotch)

t

G2

Fr ( b) Pr of il e fo r a c r otc h

—

—

—

α > 40: G = 1

—

—

—

0 to 1

0 to 1

—

30 min.

30 min.

—

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Single-bevel butt weld, welded one side without backing (see Note 5

109

AS/NZS 1554.6:2012

APPENDIX E

CORROSION TESTING (Informative) E1 GENERAL Corrosion testing is commonly used to ensure consistency of product from one heat to another and to ensure suitability for an application. Depending on the type of application and specific end use, it is most important to select an appropriate test. E2 PITTING CORROSION TESTS (See ASTM G48)


The pitting corrosion test is used as a rapid product screening test to ensure that any heat variations and weld parameters will give a desired minimum level of pitting resistance. The principal should specify the test period and temperature. A typical example for alloys suitable for seawater service is a 24 h test which should show no signs of pitting at 20°C. E3 INTERGRANULAR CORROSION TESTS Poor welding practice or heat treatment in some alloys can cause carbides or intermetallic phases to form which can lead to poor corrosion performance, e.g. intergranular corrosion. The most common location for these particles is on grain boundaries which causes intergranular corrosion and faceted corrosion surfaces. The oxalic acid etch, Huey and Strauss tests are regularly used for product and weld acceptance criteria. For austenitic materials the Standards are AS 2205.10.1, AS 2038 and ASTM A262. For ferritics it is ASTM A763. E4 OTHER CORROSION TESTS Several other tests may be specified such as stress-corrosion cracking, salt spray testing and environment exposure. Most of these are elaborate, expensive and time consuming and hence are not used for product or weld screening. They can be used at the design stage. The principal may also determine and specify particular corrosion tests. The test procedure and acceptance criteria should be clearly spelt out in any tender documents. For duplex and super duplex grades, ASTM A923 has a series of chemical and mechanical tests which are used to demonstrate that weldments and parent materials do not contain unacceptable phase structures.

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APPENDIX F

FERRITE CONTENT OF WELDS (Informative) F1 GENERAL Weldments of both austenitic and duplex stainless steel contain ferrite in proportions ranging from 0 to 70%. Ferrite can be both beneficial and detrimental depending on the welding characteristics of the alloy and its intended service. Ferrite content is primarily a function of alloy content but may be influenced by welding parameters such as heat input, shielding gas and cooling rates. Due to the difficulty of measuring ferrite content by metallographic methods quantitatively as percent ferrite, ferrite numbers (FN) are now the accepted unit to express ferrite content in the weld. FN values are based on magnetic measurements according to ISO 8249 or ANSI/AWS A4.2. FN numbers are not intended to relate directly to percent ferrite, although at value of 10 they are considered to be similar.


F2 SOLIDIFICATION CRACKING (HOT CRACKING) Austenitic stainless steels may suffer centre-line, weld or heat affected zone cracking if a fully austenitic weld metal is used. This is particularly so in steels with high levels of phosphorus and ulphur impurities and in highly constrained joints. Centre line cracking may be structural but the other forms are usually only significant for corrosion resistance. The introduction of the amount of ferrite of 5 to 15FN to the weld metal by correct selection of filler metal effectively prevents hot cracking while maintaining high strength and ductility of the joint. The region that is not susceptible to hot cracking is identified as FA on the WRC-1992 diagram below. It exists between two solidification lines for primarily austenitic (AF) and ferritic (F) solidification. However, a number of normally fully austenitic stainless steels like 310, 304L and 254SMo cannot be expected to provide delta ferrite in their welds. Such steels have some tendency to produce hot cracks in welds and heat affected zones. While this tendency towards hot cracking cannot be totally eliminated, it can be held in check by the following: (a)

Use base metal and filler metal that are low in residual elements, especially sulphur and phosphorus.

(b)

Use low heat input procedures that produce shallow penetration and convex weld beads.

(c)

Maintain a low interpass temperature of maximum 120°C.

(d)

Skip welding to avoid heat build-up in one area.

(e)

Design weld joints and the welding sequence to minimize restraint on the solidifying weld metal.

All ferritic and duplex stainless steels solidify as ferrite and therefore resistant to solidification cracking. F3 SCHAEFFLER, DE LONG AND WRC-1992 DIAGRAMS The Schaeffler diagram, developed in 1947 was one of the first diagrams to predict structure in stainless steel welds as a function of Cr and Ni equivalents. While the Schaffler diagram can be used to roughly estimate the structure of the stainless steel welds, it can lead to some errors as it includes the effect of manganese in the Ni equivalent and the effect of silicon in the Cr equivalent, and does not include the effect of nitrogen in the Ni equivalent. COPYRIGHT

111

18

20

22

AS/NZS 1554.6:2012

24

26

28

30 18

4

16

0

16

8

A

20

6

16

12

2

24

10

14

AF 14

28

22

18

Ni eq = Ni + 3 5 C + 2 0 N + 0. 2 5 Cu

18

26

14

35

45 30

55

65

40

50

12

FA

75

60

85

70

12 95

80 90

F

10

0

10


10

18

20

22

24

26

28

30

C r e q = C r + M o + 0 .7N b

FIGURE F3 WRC-1992 DIAGRAM WITH SOLIDIFICATION MODE LINES

The De Long diagram includes the effect of nitrogen. However, like the Schaeffler diagram, it also includes the effect of manganese and silicon, leading to some errors, particularly when estimating the structure of manganese bearing stainless steels. WRC-1992 diagram includes the effect of nitrogen and excludes that of manganese and silicon. It predicts delta ferrite in the weld metal expressed in ferrite numbers. The WRC1992 diagram has been recognized by the International Institute of Welding (IIW) as the most accurate and preferable constitution diagram for estimating or predicting ferrite in nominally austenitic stainless steel weld metals (refer to WRC Bulletin 519). F4 HIGH TEMPERATURES For austenitic steels exposed to continuous service in the range of 500 to 900°C, any ferrite in the weld metal may transform to sigma phase. This is an intermetallic compound which is both hard and brittle at room temperature. This can be deleterious to material toughness. In order to reduce the negative effects of sigma phase, it is common practice to restrict ferrite content in weld metal towards the bottom of the 3FN to 8FN range. This is beneficial as it promotes a discontinuous network of ferrite in the weld metal. Since elements Mo, Cr, T and Nb significantly accelerate the formation of sigma phase from ferrite, these elements should be restricted where possible to the minimum levels within the limitation of the grade specification. Typically the sum Ti + Nb + Mo < 0.4 is adopted as the limit for these elements. F5 CRYOGENIC TEMPERATURES At cryogenic temperatures, (−196°C) ferrite becomes brittle, thus reducing the notch toughness of austenitic stainless steels at these low temperatures. For this reason, ferrite contents may be restricted in the range 3FN to 7FN. COPYRIGHT

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F6 ZERO FERRITE—SPECIAL APPLICATIONS Certain specific applications may require restricted or zero ferrite contents. Corrosion in nitric acid, urea solutions and even molten zinc can actively attack ferrite. In this case, zero ferrite consumables, usually with high nickel contents, can be used. The magnetic nature of ferrite may also require its exclusion, e.g. in the manufacture of naval minesweeping vessels. Special care should be taken in welding to use low heat inputs and joint restraint, and avoid contamination by sulphur, phosphorous and carbon. F7 DUPLEX STAINLESS STEELS


Duplex stainless steels have microstructures with about 50% ferrite so respond strongly to a magnet. They are unsuitable for service at temperatures between 300°C and 900°C because they become brittle over time and they also have poor ductility at temperatures below about −40°C. In the remainder of applications, for which they give excellent service, it is common to have ferrite contents in the range 30FN to 60FN. The ultimate ferrite-austenite balance in the weld metal and heat affected zone is dependent on weld and base metal composition and cooling rate. Therefore accurate predictions of ferrite numbers in the weld metal using constitution diagrams are difficult. F8 FERRITE NUMBER DETERMINATION The ferrite number of the austenitic or duplex weldments should be determined by magnetic instruments in accordance with ISO 8249 or ANSI/AWS A4.2. Alternatively, for austenitic stainless steels, the ferrite number can be calculated based on the chemical composition of the base and filler material, and the level of dilution using Figure F3.

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APPENDIX G

MATTERS FOR RESOLUTION (Normative)


The following matters of a contractual nature shall be resolved: (a)

Nomination of alloy grade, weld categories, surface finish (grade and method) and nominal tensile strength of weld (see Clauses 1.6 and 3.1.2).

(b)

Filler metals manufacturer’s certificates (see Clause 2.4.1).

(c)

Where seal welds are required (see Clause 3.5).

(d)

Approval of welding procedures (see Clause 4.1).

(e)

Method of qualification of welding procedure and prequalification of consumables including gases (see Clauses 4.2 and 4.6).

(f)

Charpy V test (see Table 4.7.1).

(g)

Corrosion test (see Clause 4.7.7).

(h)

Ferrite content determination (see Clause 4.7.8).

(i)

Surface discolouration (see Clause 6.2.6)

(j)

Availability of records for perusal by the inspector (see Clause 4.10).

(k)

Qualifications of welding supervisor (see Clause 4.12.1).

(l)

Qualifications of welders (see Clause 4.12.2).

(m)

Welding and cutting under stress (see Clause 5.15.2).

(n)

Correction of distortion (see Clause 5.15.3).

(o)

Preheat and interrun temperatures (see Clause 5.10).

(p)

Leak test water (see Clause 5.21).

(q)

Type and extent of inspection including requirements for NDE, and the value of L as the basis for assessment under Table 6.3.1(A), and 6.3.1(B) (see Clauses 6.4, 6.5, 6.6, 7.3 and 7.4).

(r)

NDE technique (see Clauses 6.4.1, 6.5.1, and 6.6.1).

(s)

Correction of faulty (defective) weld and cost of weld repair and associated NDE (see Clause 6.4.3, 6.5.2, and 6.7).

(t)

Whether test report is required (see Clause 6.8).

(u)

Preheat and post-weld heat treatment (see Clause 1.8)

Where practicable, the principal should resolve any problems with the fabricator before work is commenced.

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APPENDIX H

WELDING DISSIMILAR METALS (Informative) H1 GENERAL In welded fabrications it is reasonably common to require a join between two different stainless steels or between a stainless steel and carbon steel. Where welding consumables are matched with the steel types in compliance with Table 4.6.1, they should be deemed prequalified. This informative appendix discusses factors that determine properties of dissimilar metal welds.


The three factors that determine weld metal properties are— (a)

physical properties such as thermal expansion, thermal conductivity, magnetic properties and melting point;

(b)

metallurgical microstructure and phases formed on solidification; and

(c)

differences in corrosion resistance across the weld.

Thermal property differences may cause post weld distortion or movement during welding unless the heat input is limited and the joint is adequately restrained. One technique to avoid movement during welding is to tack ends, centre, 1/4 points and possibly 1/8 points in that order. Welding magnetic materials to non-magnetic austenite will cause arc deflections. Melting point differences can cause hot tears in the lower melting point side of the weld (this is not the same as hot cracking in fully austenitic welds that are restrained). However, the major issue is the properties of the solidified weld and whether it will have adequate ductility during solidification and any phase changes that might occur. The diagrams used to predict the weld solidification properties were developed by Schaeffler and DeLong. Some of the included elements are incorrect but the diagrams are still widely used. The diagrams were corrected and extended to high levels of ferrite in the WRC-1992 diagram. Subsequent versions have included martensite formation as well as high ferrite levels (refer to WRC Bulletin 519). Following welding, the weld area must have slag and heat tint removed so weld integrity can be assessed and also to allow the metal to be painted. If possible blast the heat affected area with iron free grit but if that is not possible grind along the weld line to avoid dragging carbon steel contamination onto the stainless steel. A stainless steel wire brush will not adequately clean the surface for the required painting. If the weld is to be used in a corrosive environment, the surface roughness should be less than 0.5 µm Ra as specified in finish 2K of EN 10088-2. ASTM A380 provides two chemical treatments for ‘cleaning’ stainless/carbon steel welds but they are rarely used as they are slow, hot and may not remove the chromium depleted layer under the weld scale. When the carbon steel is painted, carry the paint onto the stainless for 50 mm beyond the weld line to cover the stainless area which has been heat affected. Do not use an inhibitive primer (such as a zinc-based formulation) on the stainless steel as any penetration of water through the topcoat will cause galvanic effects between the zinc and the underlying stainless steel. This reaction would blister the topcoat. If there is no organic coating applied, then the stainless steel nearest to the weld will probably suffer rust staining. The galvanizing near the weld will corrode by galvanic action and initially cause a white ring of zinc corrosion product as the galvanizing is consumed. COPYRIGHT

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Specialist advice is required to weld copper-base alloys as there is a possibility of liquid metal embrittlement. This cracking can also be an issue with remnants of galvanized carbon steel or galvanized strapping. H2 AUSTENITIC STAINLESS STEELS TO STRUCTURAL CARBON STEEL


309L is the most commonly used filler metal for such joints when the stainless steel is one of the common grades such as 304, 304L, 316 or 316L. Filler material with at least 10FN in the all-weld-metal is recommended as the ‘safe’ choice, or alternatively 18 8 Mn high manganese fully austenitic filler. The figure below illustrates the analysis leading to a prediction of ferrite in the root pass of a joint between 304 and carbon steel made with 309LSi filler metal, using the WRC-1992 diagram with the axes extended to zero and including the martensite boundary for 1% Mn composition (refer to WRC Bulletin 519). A tie-line is first drawn between the composition of the two base metals. The 50/50 mix of both weld metals is represented by the midpoint of this tie-line. Then a second tie-line is drawn from this point to the composition of the filler metal. If the expected dilution is 30%, the predicted root pass is found at a point 30% of the distance from the filler metal composition to the midpoint. The predicted ferrite content in this example is 5FN, and it lies in the ‘safe’ range of compositions between dotted lines labelled ‘FA’. The goal is to produce a weld metal that is in the FA region. Placing weld metal in the AF or A area will increase the likelihood of solidification (hot) cracking. Crossing the martensite boundary means that bend tests will fail. WRC Bulletin 519 gives diagrams with more martensite boundaries to cover a wide range of steels. In cases where higher nickel stainless steels, such as 310, 320, 330 or 904L are to be welded to structural steel, a filler metal of ferrite content higher than 10FN may be necessary in order to avoid solidification cracking (to place weld metal in the ‘safe’ FA region of Figure H2).

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18 2 A

16

10

4

20 30

AF FA

50 ER309LSi

Ni Equivalent = Ni + 35 C + 20 N + 0. 25 Cu

14 30

40

12

70

F

90

WELD

304

10

MIXTURE OF B A S E M E TA L S

8

A36

6

M A R T E N S I T E B O U N D A R Y @ 1% M n

4


2

0 0

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

C r E q u i v a l e n t = C R + M o + 0 .7 N b

(Reproduced with permission from American Welding Society, Miami, FL.)

FIGURE H2 WRC-1992 DIAGRAM SHOWING WELDING OF 304 STAINLESS TO CARBON STEEL USING 309LSI FILLER METAL

H3 FERRITIC STAINLESS STEELS TO STRUCTURAL CARBON STEEL The 12% Cr ferritic stainless steels such as 405 and 409 can be welded to structural steel with mild steel electrodes, although the austenitic stainless steel filler 309L is prequalified. Grade 1.4003 is prequalified for welding to carbon steel with 309Lmo but other austenitic fillers including 309L, 308L and 18 8 Mn have been successfully used. Higher alloy ferritic stainless steels are best welded to carbon steel with 309L filler metal. Alloy filler metals higher than 309L are generally unnecessary for such joints, though they can be used. H4 MARTENSITIC STAINLESS STEELS STRUCTURAL CARBON STEEL If postweld heat treatment is planned, then a 12% Cr martensitic stainless steel such as 410 or 410NiMo can be welded to structural steel with mild steel filler material and proper preheat. However, if PWHT is not in the plan, then the austenitic filler metals of at least 10FN become the best choices beginning with 309L. For higher alloy martensitic stainless steel such as 420, then only high ferrite austenitic stainless steel filler metals such as 309L, 309Lmo, 2209 or 312 are appropriate to obtaining a least 3FN in the deposit. H5 DUPLEX STAINLESS STEELS TO STRUCTURAL CARBON STEEL 309L is generally the best choice for filler metal, although there is no harm, other than filler metal cost, in using filler metals of still higher ferrite content such as 2209 duplex stainless steel.

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H6 ALTERNATIVE FILLER MATERIAL


For welding of stainless steel to carbon steel, 18 8 Mn (sometimes referred to as 307 “modified”) filler may be used in lieu of 309L filler. The 18 8 Mn composition differs from the 307 composition in that 307 contains Mo whereas 18 8 Mn does not, and 307 contains less Mn than does 18 8 Mn. The higher manganese content of 18 8 Mn shifts the martensite boundary in the Figure H2 anticlockwise, reducing martensite content of the weld metal. This increases resistance of the weld metal to cracking. The WRC-1992 diagram with different martensite boundaries is discussed in WRC Bulletin 519.

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BIBLIOGRAPHY AS 2038

Methods for detecting the susceptibility of austenitic stainless steels to intergranular corrosion

2205

Methods for destructive testing of welds in metal

2205.3.3

Method 3.3

Longitudinal guided bend test

2205.10.1 Method 10.1: Corrosion test for welded austenitic stainless steel 4037

Pressure equipment—Examination and testing

4100

Steel Structures

AS/NZS 4673

Cold-formed stainless steel structures

AS/NZS ISO 31000 Risk management—Principles and guidelines


ASTM A262

Practices for detecting susceptibility to intergranular attack in austenitic stainless steels

A763

Standard practices for detecting susceptibility to intergranular attack in ferritic stainless steels

A923

Standard test methods for detecting detrimental intermetallic phase in duplex austenitic/ferritic stainless steels

G48

Test method for pitting and crevice corrosion resistance of stainless steels and related alloys by the use of ferric chloride solution

ASME BPE

Bioprocessing equipment

B31.3

Process piping

B46.1

Surface texture (surface roughness, waviness, and lay)

IIW Doc. II-1159-91 The effect of the ratio between gauge length and diameter on elongation in tensile tests on duplex stainless steel or weld metals by shielded metal arc welding UNS

Metals and alloys in the unified numbering system

SEW 400 Stahl-Eisen-Werkstoffblatter EN 10088-2

Stainless steels—Part 2: Technical delivery conditions for sheet/plate and strip for general purposes

WRC Bulletin 519, Stainless Steel Weld Metal—Prediction of Ferrite Content Damian Kotecki AWS D1.6

Structural welding code—Stainless Steel

D18.1

Specification for welding of austenitic stainless steel tube and pipe systems in sanitary (hygienic) applications

D18.2

Guide to Weld Discoloration Levels on Inside of Austenitic Stainless Steel Tube.

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WTIA TN03

Care and conditioning of arc welding consumables

TN07

Health and safety in welding

TN10

Fracture mechanics

TN13

Stainless steels for corrosive environments

TN16

Welding stainless steels

TN22

Welding electrical safety

ASSDA Reference Manual


MAF NZCP 6 Design and Layout of Manufacturing Premises Code of Practice

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AS/NZS 1554.6:2012 120

NOTES

Standards Australia Standards Australia is an independent company, limited by guarantee, which prepares and publishes most of the voluntary technical and commercial standards used in Australia. These standards are developed through an open process of consultation and consensus, in which all interested parties are invited to participate. Through a Memorandum of Understanding with the Commonwealth


government, Standards Australia is recognized as Australia’s peak national standards body.

Standards New Zealand The first national Standards organization was created in New Zealand in 1932. The Standards Council of New Zealand is the national authority responsible for the production of Standards. Standards New Zealand is the trading arm of the Standards Council established under the Standards Act 1988.

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International Involvement Standards Australia and Standards New Zealand are responsible for ensuring that the Australian and New Zealand viewpoints are considered in the formulation of international Standards and that the latest international experience is incorporated in national and Joint Standards. This role is vital in assisting local industry to compete in international markets. Both organizations are the national members of ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission).

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1554.6-2012 Welding of Stainless Steels for Structural Purposes

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