GBT 699-1999

GB/T 699—1999 ————————————————————————————————————————

Where steel material with size larger than 80mm to 120mm is re-forged to test piece sized between 70mm and 80mm, the result of the sampling test should comply with the stipulation in Table 3. Where steel material with size larger than 120mm to 250mm is re-forged to test piece sized between 90mm and 100mm, the result of the sampling test should comply with the stipulation in Table 3. 6.4.3 The hardness of steel material for cutting work or for cold drawn material in the delivery

state should comply with the stipulation in Table 3. For the hardness of non-annealed steel, if the supplier can guarantee the conformance, the test may be omitted. The hardness indexes after high temperature tempering and normalization shall be determined by agreement between the supplier and the buyer. Table 3 Proposed heat

No.

n o i t a n g i s e D

Mechanical Properties

treatment, ℃

Hardness of steel material in delivery state

Specimen blank size mm

n o i t a z i l a m r o N

g n i h c n e u Q

g n i r e p m e T

σ b

σs

δ5

ψ

AKU2

MPa

MPa

%

%

J

HBS10/3 Non-heat

Not less than

treated steel

000

Annealed steel

1

08F

25

930

295

175

35

60

131

2

10F

25

930

315

185

33

55

137

3

15F

25

920

355

205

29

55

143

4

08

25

930

325

195

33

60

131

5

10

25

930

335

205

31

55

137

6

15

25

920

375

225

27

55

143

7

20

25

910

410

245

25

55

156

8

25

25

900

870

600

450

275

23

50

71

170

9

30

25

880

860

600

490

295

21

50

63

179

10

35

25

870

850

600

530

315

20

45

55

197

11

40

25

860

840

600

570

335

19

45

47

217

187

12

45

25

850

840

600

600

355

16

40

39

229

197

13

50

25

830

830

600

630

375

14

40

31

241

207

14

55

25

820

820

600

645

380

13

35

255

217

7

GB/T 699—1999 ————————————————————————————————————————

Table 3 Proposed heat n o i t a n g i s e D

No.


treatment, ℃




g n i h c n e u Q

g n i r e p m e T

σ b

σs

δ5

ψ

AKU2

MPa

MPa

%

%

J

HBS10/3 Non-heat

Not less than

treated steel

000

Annealed steel

15

60

25

810

675

400

12

35

255

229

16

65

25

810

695

410

10

30

255

229

17

70

25

790

715

420

9

30

269

229

18

75

specimen

820

480

1 080

880

7

30

285

241

19

80

specimen

820

480

1 080

930

6

30

285

241

20

85

specimen

820

480

1 130

980

6

30

302

255

21

15Mn

25

920

410

245

26

55

163

22

20Mn

25

910

450

275

24

50

197

23

25Mn

25

900

870

600

490

295

22

50

71

207

24

30Mn

25

880

860

600

540

315

20

45

63

217

187

25

35Mn

25

870

850

600

560

335

18

45

55

229

197

26

40Mn

25

860

840

600

590

355

17

45

47

229

207

27

45Mn

25

850

840

600

620

375

15

40

39

241

217

28

50Mn

25

830

830

600

645

390

13

40

31

255

217

29

60Mn

25

810

695

410

11

35

269

229

30

65Mn

25

830

735

430

9

30

285

229

31

70Mn

25

790

785

450

8

30

285

229

Notes: 1. For steel material with diameter or thickness less than 25mm, heat treatment is conducted on the specimen blank with the same cross-section size as that of finished products. 2. The proposed temperature holding time for normalization as listed in the table is not less than 30 minutes with air cooling; that for quenching is not less than 30 minutes with oil cooling for 75, 80 and 85 steels and water cooling for other steels; that for tempering is not less than 1 hour.

8

GB/T 699—1999 ————————————————————————————————————————

6.5 Upsetting 6.5.1 Steels for upsetting work shall be subject to upsetting test and either hot upsetting or cold

upsetting should be clearly stated in the contract. The height of specimen after hot upsetting shall be as much as 1/3 of that of the original specimen; the height of specimen after cold upsetting shall be as much as 1/2 of that of the original specimen. No fissure or fracture shall exist on the specimen after the upsetting. 6.5.2 For steel material with size larger than 80mm that requires hot upsetting, or that with size

larger than 30mm that requires cold upsetting, if the supplier can guarantee the conformance, the test may be omitted. 6.6 Macroscopic Structure 6.6.1 There should be no shrinkage cavity, blister, crack, inclusion, skull patch or fish eye

visible to the naked eyes on the cross-sectional pickled macroscopic structure specimen of killed steel material. Such imperfections as subsurface inclusion not exceeding the allowable depth for surface imperfection are allowed on the steel material for cutting work. 6.6.2 Pickled macroscopic structure should comply with the stipulation in Table 4.

Table 4

Quality grade

General poriness

Central poriness

Ingot mold aliquation

Level (not greater than) Quality steel

3.0

3.0

3.0

Premium-grade quality steel

2.5

2.5

2.5

Special-grade quality steel

2.0

2.0

2.0

6.6.3 If the supplier can guarantee the conformance of macroscopic test, it is allowable to

substitute ultrasonic test or other nondestructive tests specified in standard GB/T 7736 for the macroscopic test. 6.7 Non-metallic Inclusion

As required by the buyer, non-metallic inclusions may be tested with the acceptable levels to be defined by agreement between the buyer and the supplier. 6.8 Decarburized Layer

When testing the decarburized layer of steels with nominal carbon content higher than 0.30%, as required by the buyer, the total depth of decarburized layer on each side (ferrite + transition layer) should comply with the stipulation in Table 5. The buyer should indicate the group in the contract.

9

GB/T 699—1999 ————————————————————————————————————————

Table 5

mm

Group

Allowable total depth of decarburized layer (not higher than)

Group I

1.0%D

Group II

1.5%D

Note: D is the nominal diameter or thickness of steel material

6.9 Surface Quality 6.9.1 There should be no crack, rolling skin, folding or inclusion visible to the naked eyes on

the surface of steel material for pressed work. Any of the above imperfections should be removed to such extent that the removed depth as calculated from the surface of steel material is in compliance with the stipulation in Table 6. The width for removal should not be less than 5 times the depth. For steel material with diameter or side length larger than 140mm, no more than 2 places with maximum removal depth are allowed on the same cross section. It is allowable to have very few fine scratches, impression marks and pork marks with size not exceeding half of the size allowance as calculated from the actual size and fine crackles with depth within 0.2mm in existence. 6.9.2 Local imperfections with depth not exceeding the stipulation in Table 7 as calculated

from the nominal size of steel material are allowable on the surface of steel material for cutting work. mm

Table 6

Nominal size of steel material (diameter or depth) < 80 80~140

Allowable depth of imperfection removal 1/2 of nominal size allowance of steel material Nominal size allowance of steel material

>140 ~ 200

5% of nominal size of steel material

> 200

6% of nominal size of steel material

mm

Table 7

Nominal size of steel material

Allowable depth of local imperfection

(diameter or thickness)

(not greater than)

< 100 ≥ 100

Negative allowance of nominal size of steel material Allowance of nominal size of steel material

10

GB/T 699—1999 ————————————————————————————————————————

6.10 Special Requirements

As required by the buyer and so agreed between the buyer and the supplier, steel material meeting the following special requirements maybe supplied: a) To narrow or modify the range of chemical composition specified in Table 1; b) Steel bars with diameter or thickness larger than 250mm; c) To test the grain fineness of steel; d) To test the microstructure of steel; e) To test the hair line seams with telescoping (tower) specimen; f) To make the mechanical properties indexes stricter; g) To make V-notched impact test (the indexes to be agreed between the buyer and the supplier); h) Other. 7 Test Methods

Test methods for each and every batch of steel material should comply with the stipulation in Table 8. Table 8. No. 1

Test item Chemical

Quantity of

Location for sampling

samples 1

GB/T 222

composition 2

Tensile test

Test method GB/T 223 GB/T 4336

2

Different pieces of steel material

GB/T 228 GB/T 2975 GB/T 6397

3

Hardness test

3


GB/T 231

4

Impact test

2


GB/T 229

5

Upsetting test

2


GB/T 233

6

Macroscopic

2

Different pieces of steel billet or steel

GB/T 226

material equivalent to the end of steel

GB/T 1979

structure

ingot 7

Telescoping

2


GB/T 15711

2


GB/T 224

(tower) hair line seams 8

Decarburization

(Metallo-graphic) 11

GB/T 699—1999 ————————————————————————————————————————

Table 8.

No.

Test item

Quantity of

Location for sampling

samples

Test method

9

Grain fineness

1

Any piece of steel material

YB/T 5148

10

Non-metallic

2


GB/T 10561

inclusion 11

Microstructure

2


GB/T 13299

12

Ultrasonic test

2

On the whole of steel material

GB/T 7736

13

Size,

Piece by

On the whole of steel material

Caliper,

dimensions 14

Visual aspects

piece Piece by

micrometer On the whole of steel material

Visual inspection

piece 8 Test Rules 8.1 Inspections and Acceptance 8.1.1 The quality of steel material shall be inspected and accepted by the quality technical

supervision department of the supplier. 8.1.2 The supplier must ensure that the steel material delivered complies with the stipulations

of this standard or of the contract. The buyer is entitled to make inspection or acceptance to any of the test items defined in this standard or the contract if necessary. 8.2 Batch Forming Rules

Steel material should be inspected and accepted batchwise. Each batch consists of steel material with the same heat (furnace) number, the same working method, the same size, the same delivery state (or the same heat treatment system/furnace lot) and the same surface state. 8.3 Quantity and Location for Sampling

The quantity and location for sampling of steel material should comply with the stipulation in Table 8. 8.4 Re-inspection and Judging Rules 8.4.1

The re-inspection and judging rules shall be in compliance with relevant stipulations in

8.3.4.3 of standard GB/T 17505-1998. 8.4.2

If the supplier can guarantee the conformance of the steel material, it is allowable to

substitute billet for material or large pieces for small ones with respect to the test results of macroscopic test, mechanical properties and non-metallic inclusion for the steel material or ingots with the same heat (furnace) number. 12

GB/T 699—1999 ————————————————————————————————————————

9 Packaging, Marking and Quality Certificate

Packaging, marking and quality certificates of the steel material should comply with the stipulations of GB/T 2101. Annex A

Annex to the Standard

Normative References - Methods for Chemical Analysis

GB/T 223.3 – 1988

Methods for chemical analysis of iron, steel and alloy ― The

diantipyryl-methane phosphomolybdic acid gravimetric

method for the determination of phosphorus content GB/T 223.5 – 1997

Methods for chemical analysis of iron, steel and alloy ―

The reduced molybdosilicate spectrophotometric method for the determination of acid-soluble silicon content

GB/T 223.10 - 1991


The determination of aluminum content by chrome azurol S photometric method after separation with cupferron

GB/T 223.11 - 1991


The determination of chromium content by persulfate oxdation volumetric method

GB/T 223.12 - 1991


The determination of chromium content by diphenyl carbazide photometric method after separation with sodium carbonate

GB/T 223.18 - 1994


The sodium thiosulfate separation iodimetric method for the determination of copper content

GB/T 223.19 - 1989


The determination of copper content by neocuprone-photometric method

GB/T 223.23 - 1994


The

dimethylglyoxime

spectrophotometric

method

for

the

determination of nickel content GB/T 223.24 - 1994


The extraction separation - The dimethylglyoxime spectrophoto method for the determination of nickel content

GB/T 223.36 - 1994


The neutral titration method for the determination of nitrogen content after distillation separation 13

GB/T 699—1999 ————————————————————————————————————————

GB/T 223.37 - 1989


The indigo photometric method for the determination of nitrogen content after distillation separation

GB/T 223.53 - 1987


The determination of copper content by flame atomic absorption spectrophotometry

GB/T 223.54 - 1987


The determination of nickel content by flame atomic absorption spectrophotometry

GB/T 223.58 - 1987


The determination of manganese content by sodium arsenite – sodium nitrite titration method

GB/T 223.59 - 1987


The

determination

of

phospgorus

content

by

antimonium-Phosphorus-Molybdium-blue photometric method GB/T 223.60 - 1997


The perchloric acid dehydration gravimetric method for the determination of silicon content

GB/T 223.61 - 1988


The

determination

of

phosphorus

content

by

ammonium

molybdo-phosphate volumetric method GB/T 223.62 - 1988


The determination of phosphorus content by butyl acetate extraction photometric method

GB/T 223.63 - 1988


The determination of manganese content by sodium (potassium) permanganate photometric method

GB/T 223.64 - 1988


The determination of manganese content by flame atomic absorption spectrometric method

GB/T 223.67 - 1989


The determination of sulfur content methyl dyne blue photometric method after reduced distillation

GB/T 223.68 - 1997


The potassium iodated titration method after combustion in the pipe furnace for the determination of sulfur content

GB/T 223.69 - 1997


The gas-volumetric method after combustion in the pipe furnace for the determination of carbon content 14

GB/T 699—1999 ————————————————————————————————————————

GB/T 223.71 - 1997


The volumetric method after combustion in the pipe furnace for the determination of carbon content

GB/T 223.72 - 1991


Aluminum oxide stratography - barium sulfate gravimetric method for the determination of sulfur content

—————————

15

GB/T 699—1999 ————————————————————————————————————————

GB/T 908-1987

Size, dimensions, weight and allowance of forged round and square steels

GB/T 1979-1980

Grading

diagrams

for

evaluation

of

macroscopic

structural

imperfections of structural steels GB/T 2101-1989

General stipulations on acceptance, packaging, markings and quality certificates of profile steels

GB/T 2975-1998

Steel and steel products - Location and preparation of test specimens for mechanical testing

GB/T 4336-1984

Method for photoelectric emission spectroscopic analysis of carbon steel, medium and low alloy steel

GB/T 6397-1986

Specimens for tensile test of metals

GB/T 7736-1987

Ultrasonic inspecting method for macro-structure and imperfection of steel

GB/T 10561-1989

Steel - Determination of content of non-metallic inclusion Micrographic method using standard diagrams

GB/T 17616-1998

Unified numbering system for designations of iron, steel and alloy

GB/T 13299-1991

Steel - Determination of microstructure

GB/T 15711-1995

Steel products - Methods for acid etch test of tower sample

GB/T 17505-1998

Steel and steel products - General technical delivery requirements

YB/T 5148-1993

Method for the test of mean grain fineness of metals

See Annex A (Annex to the Standard) for normative references for chemical analysis methods of various elements in steel. 3 Order Information

Contracts concluded or purchase orders placed in compliance with this standard should contain the following information ： a）Standard code number ； b）Description of product ； c）Designations or unified numerical code ； d）Weight (quantity) of delivery ； e）Class of accuracy for specification and size ； f ）Processing method used ； g）State of delivery； h）Impact test (where required, as per 6.4.1) ； i）Upsetting test (where required, as per 6.5) ； j） Non-metallic inclusion (where required, as per 6.7)； k ）Decarburized layer (where required, as per 6.8) ； l）Special requirements (where required, as per 6.10) ； 3

GB/T 699—1999 ————————————————————————————————————————

4 Classifications and Code 4.1 Steel material is classified according to its metallurgical quality as follows:

Quality Steel Premium-grade Quality Steel

A

Special-grade Quality Steel

E

4.2 Steel material is classified into two categories according to the processing method used:

a) Steel for pressed work

UP

Steel for hot pressed work

UHP

Steel for upsetting work

UF

Steel for cold drawn billet

UCD

b) Steel for cutting work

UC

5 Size, Dimensions, Weight and Allowance 5.1 The size, dimensions and allowance of hot rolled round steels and square steels should

comply with relevant stipulations in GB/T 702. Specific requirements should be clearly stated in the contract. 5.2 The size, dimensions and allowance of forged round and square steels should comply with

relevant stipulations in GB/T 908. Specific requirements should be clearly stated in the contract. 5.3 The size, dimensions and allowance of steels with other cross-sections should comply with

relevant stipulations in corresponding standards. 6 Technical Requirements 6.1 Designations, Code and Chemical Composition 6.1.1 Designations unified numerical code and chemical composition (smelting analysis) of

steels should comply with Table 1. 6.1.1.1 Sulfur and phosphorus contents of steels should comply with Table 2. 6.1.1.2 The allowable copper content of steels smelted with steel scrap should not be higher

than 0.30%. 6.1.1.3 The copper content of steels for hot pressed work should not be higher than 0.20%. 6.1.1.4 The manganese content of 35~38 steels for lead-bath quenched steel wires should be

0.30%~0.60%; the chromium content should not be higher than 0.10%, the nickel content should not be higher than 0.15%, the copper content should not be higher than 0.20%; the sulfur and phosphorus contents should comply with the requirements of steel wire standards. 6.1.1.5 For aluminum deoxidization smelted killed steel for 08 steels, the lower limit of

manganese content is 0.25%, the silicon content should not be higher than 0.03% and the aluminum content should be 0.02%~0.07%. In this case the designation of the steel is 08Al.

4

GB/T 699—1999 ————————————————————————————————————————

Table 1 No.

Unified numerical code

Chemical composition ，% Designation

C

Si

Mn

Cr

Ni

Cu

Not higher than

1

U20080

08F

0.05~0.11

≤0.03

0.25~0.50

0.10

0.30

0.25

2

U20100

10F

0.07~0.13

≤0.07

0.25~0.50

0.15

0.30

0.25

3

U20150

15F

0.12~0.18

≤0.07

0.25~0.50

0.25

0.30

0.25

4

U20082

08

0.05~0.11

0.17~0.37

0.35~0.65

0.10

0.30

0.25

5

U20102

10

0.07~0.13

0.17~0.37

0.35~0.65

0.15

0.30

0.25

6

U20152

15

0.12~0.18

0.17~0.37

0.35~0.65

0.25

0.30

0.25

7

U20202

20

0.17~0.23

0.17~0.37

0.35~0.65

0.25

0.30

0.25

8

U20252

25

0.22~0.29

0.17~0.37

0.50~0.80

0.25

0.30

0.25

9

U20302

30

0.27~0.34

0.17~0.37

0.50~0.80

0.25

0.30

0.25

10

U20352

35

0.32~0.39

0.17~0.37

0.50~0.80

0.25

0.30

0.25

11

U20402

40

0.37~0.44

0.17~0.37

0.50~0.80

0.25

0.30

0.25

12

U20452

45

0.42~0.50

0.17~0.37

0.50~0.80

0.25

0.30

0.25

13

U20502

50

0.47~0.55

0.17~0.37

0.50~0.80

0.25

0.30

0.25

14

U20552

55

0.52~0.60

0.17~0.37

0.50~0.80

0.25

0.30

0.25

15

U20602

60

0.57~0.65

0.17~0.37

0.50~0.80

0.25

0.30

0.25

16

U20652

65

0.62~0.70

0.17~0.37

0.50~0.80

0.25

0.30

0.25

17

U20702

70

0.67~0.75

0.17~0.37

0.50~0.80

0.25

0.30

0.25

18

U20752

75

0.72~0.80

0.17~0.37

0.50~0.80

0.25

0.30

0.25

19

U20802

80

0.77~0.85

0.17~0.37

0.50~0.80

0.25

0.30

0.25

20

U20852

85

0.82~0.90

0.17~0.37

0.50~0.80

0.25

0.30

0.25

21

U21152

15Mn

0.12~0.18

0.17~0.37

0.70~1.00

0.25

0.30

0.25

22

U21202

20Mn

0.17~0.23

0.17~0.37

0.70~1.00

0.25

0.30

0.25

23

U21252

25Mn

0.22~0.29

0.17~0.37

0.70~1.00

0.25

0.30

0.25

24

U21302

30Mn

0.27~0.34

0.17~0.37

0.70~1.00

0.25

0.30

0.25

25

U21352

35Mn

0.32~0.39

0.17~0.37

0.70~1.00

0.25

0.30

0.25

26

U21402

40Mn

0.37~0.44

0.17~0.37

0.70~1.00

0.25

0.30

0.25

27

U21452

45Mn

0.42~0.50

0.17~0.37

0.70~1.00

0.25

0.30

0.25

28

U21502

50Mn

0.48~0.56

0.17~0.37

0.70~1.00

0.25

0.30

0.25

29

U21602

60Mn

0.57~0.65

0.17~0.37

0.70~1.00

0.25

0.30

0.25

30

U21652

65Mn

0.62~0.70

0.17~0.37

0.90~1.20

0.25

0.30

0.25

31

U21702

70Mn

0.67~0.75

0.17~0.37

0.90~1.20

0.25

0.30

0.25

Note: Those listed in Table 1 are quality steels. In case of premium-grade quality steel, letter "A" shall be added to the end of the designation number (the last digit of the unified numerical code to be changed to "3"); in case of special-grade quality steel, letter "E" shall be added to the end of the designation number (the last digit of the unified numerical code to be changed to "6"); for rimming steel, the end of the designation number is "F" (the last digit of the unified numerical code being "0"); for semi-killed steel, the end of the designation number is "b" (the last digit of the unified numerical code being "1"). 5

GB/T 699—1999 ————————————————————————————————————————

6.1.1.6 The silicon content of rimming steel for cold punch pressing should not be higher than

0.03%. 6.1.1.7 The nitrogen content of steels smelted in oxygen-blown converters should not be higher

than 0.008%. If the supplier can guarantee the conformance, the analysis may be omitted. 6.1.1.8 As agreed between the buyer and the supplier, for 08~25 steels, semi-killed steels with

silicon content not higher than 0.17% may be supplied, with grade numbers of 08b~25b. 6.1.2 The allowance for chemical composition of steel material (or billets) should comply with

the stipulation in Table 2 of GB/T 222-1984. Table 2 P

Group

S Not higher than, %

Quality steel

0.035

0.035


0.030

0.030


0.025

0.020

6.2 Smelting Method

Unless otherwise specified in the contract, the smelting method shall be chosen by the manufacturer of its own accord. 6.3 State of Delivery

Steel material is normally delivered in the hot rolled or hot forged state. It may also be delivered in the heat treated (annealed, normalized or high temperature tempered) if the buyer so requests and if so stated in the contract. 6.4 Mechanical Properties 6.4.1 The longitudinal mechanical properties of steel material obtained by testing the specimen

made with heat-treated (normalized) work blank (excluding impact absorbed work) should comply with the stipulation in Table 3. For steel material delivered in the hot rolled or hot forged state, if the supplier can guarantee the conformance, the tests may be omitted. As required by the buyer, the impact absorbed work of 25~50 and 25Mn~50Mn steels obtained by testing the specimen made with heat treated (quenched + tempered) work blank should comply with the stipulation in Table 3 Round steels with diameter smaller than 16mm and square or flat steels with thickness not greater than 12mm shall not be subject to the impact test. 6.4.2 The mechanical properties shown in Table 3 are only applicable to steel material with

cross-section size not greater than 80mm. For that with cross-section greater than 80mm, the after-breaking elongation and percentage reduction of section are allowed to be lower than those specified in Table 3 by 2% (absolute) and 5% (absolute) respectively. 6

GB/T 699—1999 ————————————————————————————————————————

Where steel material with size larger than 80mm to 120mm is re-forged to test piece sized between 70mm and 80mm, the result of the sampling test should comply with the stipulation in Table 3. Where steel material with size larger than 120mm to 250mm is re-forged to test piece sized between 90mm and 100mm, the result of the sampling test should comply with the stipulation in Table 3. 6.4.3 The hardness of steel material for cutting work or for cold drawn material in the delivery

state should comply with the stipulation in Table 3. For the hardness of non-annealed steel, if the supplier can guarantee the conformance, the test may be omitted. The hardness indexes after high temperature tempering and normalization shall be determined by agreement between the supplier and the buyer. Table 3 Proposed heat

No.

n o i t a n g i s e D


treatment, ℃




g n i h c n e u Q

g n i r e p m e T

σ b

σs

δ5

ψ

AKU2

MPa

MPa

%

%

J

HBS10/3 Non-heat

Not less than

treated steel

000

Annealed steel

1

08F

25

930

295

175

35

60

131

2

10F

25

930

315

185

33

55

137

3

15F

25

920

355

205

29

55

143

4

08

25

930

325

195

33

60

131

5

10

25

930

335

205

31

55

137

6

15

25

920

375

225

27

55

143

7

20

25

910

410

245

25

55

156

8

25

25

900

870

600

450

275

23

50

71

170

9

30

25

880

860

600

490

295

21

50

63

179

10

35

25

870

850

600

530

315

20

45

55

197

11

40

25

860

840

600

570

335

19

45

47

217

187

12

45

25

850

840

600

600

355

16

40

39

229

197

13

50

25

830

830

600

630

375

14

40

31

241

207

14

55

25

820

820

600

645

380

13

35

255

217

7

GB/T 699—1999 ————————————————————————————————————————

Table 3 Proposed heat n o i t a n g i s e D

No.


treatment, ℃




g n i h c n e u Q

g n i r e p m e T

σ b

σs

δ5

ψ

AKU2

MPa

MPa

%

%

J

HBS10/3 Non-heat

Not less than

treated steel

000

Annealed steel

15

60

25

810

675

400

12

35

255

229

16

65

25

810

695

410

10

30

255

229

17

70

25

790

715

420

9

30

269

229

18

75

specimen

820

480

1 080

880

7

30

285

241

19

80

specimen

820

480

1 080

930

6

30

285

241

20

85

specimen

820

480

1 130

980

6

30

302

255

21

15Mn

25

920

410

245

26

55

163

22

20Mn

25

910

450

275

24

50

197

23

25Mn

25

900

870

600

490

295

22

50

71

207

24

30Mn

25

880

860

600

540

315

20

45

63

217

187

25

35Mn

25

870

850

600

560

335

18

45

55

229

197

26

40Mn

25

860

840

600

590

355

17

45

47

229

207

27

45Mn

25

850

840

600

620

375

15

40

39

241

217

28

50Mn

25

830

830

600

645

390

13

40

31

255

217

29

60Mn

25

810

695

410

11

35

269

229

30

65Mn

25

830

735

430

9

30

285

229

31

70Mn

25

790

785

450

8

30

285

229

Notes: 1. For steel material with diameter or thickness less than 25mm, heat treatment is conducted on the specimen blank with the same cross-section size as that of finished products. 2. The proposed temperature holding time for normalization as listed in the table is not less than 30 minutes with air cooling; that for quenching is not less than 30 minutes with oil cooling for 75, 80 and 85 steels and water cooling for other steels; that for tempering is not less than 1 hour.

8

GB/T 699—1999 ————————————————————————————————————————

6.5 Upsetting 6.5.1 Steels for upsetting work shall be subject to upsetting test and either hot upsetting or cold

upsetting should be clearly stated in the contract. The height of specimen after hot upsetting shall be as much as 1/3 of that of the original specimen; the height of specimen after cold upsetting shall be as much as 1/2 of that of the original specimen. No fissure or fracture shall exist on the specimen after the upsetting. 6.5.2 For steel material with size larger than 80mm that requires hot upsetting, or that with size

larger than 30mm that requires cold upsetting, if the supplier can guarantee the conformance, the test may be omitted. 6.6 Macroscopic Structure 6.6.1 There should be no shrinkage cavity, blister, crack, inclusion, skull patch or fish eye

visible to the naked eyes on the cross-sectional pickled macroscopic structure specimen of killed steel material. Such imperfections as subsurface inclusion not exceeding the allowable depth for surface imperfection are allowed on the steel material for cutting work. 6.6.2 Pickled macroscopic structure should comply with the stipulation in Table 4.

Table 4

Quality grade

General poriness

Central poriness

Ingot mold aliquation

Level (not greater than) Quality steel

3.0

3.0

3.0


2.5

2.5

2.5


2.0

2.0

2.0

6.6.3 If the supplier can guarantee the conformance of macroscopic test, it is allowable to

substitute ultrasonic test or other nondestructive tests specified in standard GB/T 7736 for the macroscopic test. 6.7 Non-metallic Inclusion

As required by the buyer, non-metallic inclusions may be tested with the acceptable levels to be defined by agreement between the buyer and the supplier. 6.8 Decarburized Layer

When testing the decarburized layer of steels with nominal carbon content higher than 0.30%, as required by the buyer, the total depth of decarburized layer on each side (ferrite + transition layer) should comply with the stipulation in Table 5. The buyer should indicate the group in the contract.

9

GBT 699-1999

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