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Introduction
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Shielded Metal Arc Welding
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Gas Metal Arc Welding
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Gas Tungsten Arc Welding
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Resistance Welding
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Brazing
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Soldering
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Dissimilar Metal Joining and We Weld ld Overlaying
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utting
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Welding We lding u!"i lad Steel #lates # lates
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Sheet $ining
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#i%e Welding
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Re&erences
Introduction u!"i alloys &ind many a%%lications in marine' %o(er' electrical and chemical industries) Ty%ical Ty%ical hard(are &a*ricated *y (elding are condenser and heat e+changer com%onents' sea(ater %i%ing' distillation a%%aratus and' demonstrating the e+cellent anti&ouling ,ualities o& Alloy -"S ./0//' the hull o& an ocean going commercial &ishing vessel' the o%%er Mariner) The com%osition o& common u!"i alloys and &iller metals is sho(n in Table 1. Table 1) om%osition o& u!"is Composition, % maximum unless shown as a range or minimum UNS Allo !re"ious Trade &ther Named Cu Ni !b #e $n n No. Names 'lements 6)7 ! u!"i' 12 Rem) 3) 3 )4 ! 0)5 )/1 6)/ 6)/ )7 ! )4 )4 C()*)) 6). 6)/ ! C()+)) u!"i' 6/2 Rem) 8)/ ! 66)/ )/ )/1 6)/ 6)/ 6)/ 6)/ 6)4 68)/ ! u!"i' 5/2 Rem) )/1 6) 6 )/ 6)/ 6) 6 )/ C(1))) 57)/ 58)/ ! C(1)) u!"i' 7/2 Rem) )/1 )3 ! ). 6)/ 6)/ 77)/ u!"i' Tin Rem) 4) 4)1 ! 6/)1 )/1 )0 )0 )1 ) 5 6)4 ! 5)4 Sn C(-)) /a0 'CuNi Rem) 58)/ ! )/5 )3 ! ).1 9c: 6)/ )51 Si
Table 1) om%osition o& u!"is Composition, % maximum unless shown as a range or minimum UNS Allo !re"ious Trade &ther Named Cu Ni !b #e $n n No. Names 'lements )/5 # /C(1)0 75)/ )5 ! )1 Ti )1 Si 58)/ ! 6)/ ! 'CuNi/b0 Rem) )/5 )3 ! ).1 9c: )/5 # /2+)(10 77)/ 5)1 )1 Ti 9a: A"SI;AWS 1).!43 9*: A"SI;AWS A1)0!43 9c: Total o& lead' zinc' tin and all other elements not named shall not e+ceed /)1/2)
Most alloys o& u!"i are solid solutions as sho(n in #igure 1) They may *e (or
While co%%er and nic
A?: or (eld metal) $ead' sul&ur and %hos%horus are %articularly detrimental and may cause intergranular hot crac
ommon sources o& the contaminating elements sul&ur and %h os%horus are mar
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remove e+cess contamination *y (i%ing (ith clean cloth s(a* the (eld area 9at least 5 in) C1 cm each side o& the (eld: (ith an organic solvent such as ali%hatic %etroleums' chlorinated hydrocar*ons or *lends o& the t(o) -se only clean solvents 9uncontaminated (ith acid' al
All the commonly used (elding %rocesses are a%%lica*le to the u!"i alloys) A nominal ./!7/ u!"i &iller metal (ith titanium as a deo+idizer is almost invaria*ly used to (eld all o& the u! "i alloys) A 8/!6/ u!"i *are &iller metal and a covered electrode is availa*le in Euro%e and occasionally used' *ut the *are (ire is generally limited to gas tungsten arc (elding 9GTAW: gages u% to /)651!in) 97!mm: thic<) Welds made (ith 8/!6/ u!"i &illers should *e limited to non!(etting sur&aces since the (eld may *e ano dic to the *ase metal) Guides &or the various (elding %rocesses &ollo() Bac< to To%
Shielded etal Arc 2elding For shielded metal arc (elding 9SMAW:' the &lu+ covered electrode Eu"i is used (ith direct current electrode %ositive 9reverse %olarity:) I& the arc length is
A s,uare!groove %re%aration &or %late u% to 6;3 in) 90)3 mm: has *een used &or &lat %osition (elding as sho(n in Table -. The more common %ractice is to limit the s,uare!groove to 6;4 in) 97)5mm: (ith a root o%ening at least hal& the sheet thic
7;75 ! 6;4 5
#iller si6e, in.
6;4
7;75
Current amps
661 ! 65/
41 ! 8/
6;60 ! 6;4 7;75 ! 6;4 5 5 7;75 96st %ass: 6;4 96st %ass: 6;4 95nd %ass: 7;75 95nd %ass: 6// 96st %ass: 6//!661 6// 95nd %ass: 81!6//95nd %ass:
7;75 6 or 5 9d: 7;75 41
9a: Eu"i electrode 9*: Welding u%hill 9c: Baco(ever' (eaving is usually necessary &or vertical u%hill and overhead %osition (elding) Weaving should *e limited to no more than three times the core (ire diameter) Bet(een %asses' sur&aces should *e cleaned o& &lu+ *y chi%%ing and;or grinding) When *ac
8as9etal Arc 2elding u!"i alloys are (elded (ith the GMAW %rocess using deo+idized &iller metal and direct current reverse %olarity) Argon or mi+tures o& argon and helium at &lo( rates o& 51!1/ &t)7;h 9/).1 ! 6)1 m7;h: are usually used) S%ray trans&er is generally used &or 6;3!in) 90)3!mm: thic< and heavier sections' *ut the %rocess is limited to the &lat %osition) For (elding sheet and %late &rom one side' grooved co%%er or u!"i *ac
Re%resentative %arameters used in @oining u!"i alloys *y GMAW s%ray arc are sho(n in Table :) urrents on the high side o& the range are &avored &or the higher conductivity' lo(er nic
Argon #low /c7h0 5/ ! 7/ 5/ ! 7/ 5/ ! 7/
5/ ! 7/ 7/ ! 1/ 7/ ! 1/ 7/ ! 1/
The ERu"i &iller com%osition %rovides (elds e,uivalent in strength to .61 // *ase metal and greater in strength than ./0//) ERu"i con tains /)5/2 to /)1/2 Ti' (hich serves as a deo+idizer to %revent %orosity and o+ygen em*rittlement) Short circuit 9GMAW!S: is a relatively lo( heat in%ut %rocess using /)/71! or /)/31!in) 9/)4! or 6)5!mm diameter: &iller metal and is (ell suited to (eld gages u nder 6;3 in) 90)3mm:) Argon shielding may *e used' *ut argon!helium mi+ture gives *etter (etting an d *etter *ead contour) The lo( heat in%ut allo(s (elding in all %ositions) #ulsed arc 9GMAW!#: incor%orates many advantages o& *oth s%ray arc and short circuit trans&er and is (ell suited &or (elding ./0// and .61// alloys) The electrode diameter is usually /)/31 in) 96)5mm: and an argon!helium mi+ture shielding gas gives good (etting and arc action) GMAW!# is ada%ta*le to (elding in all %ositions) A more recent advancement in %ulsed (elding is synergic or varia*le %ulsed (elding) With synergic (elding' the (elder has &e(er (elding varia*les to set and there is an im%rovement in (eld ,uality) One o*servation o&ten made (hen &irst GMA (elding (ith ERu"i &iller metal is that the (ire tem%er is noticea*ly lo(er than that o& iron! or n ic
8as Tungsten Arc 2elding The GTAW %rocess is the %re&erred %rocess &or (elding thin gage material' 6;60 in) 96)0mm: and less' *ut can *e a good choice &or gages u% to a*out 6;4 in) 97)5mm:) The all!%osition o%era*ility characteristic ma
com%leted *y GMAW or SMAW) Automatic GTAW e,ui%ment is availa*le &or a%%lications such as tu*e to tu*e sheet (elds' or*ital %i%e (elding and @oining sheet gages) u!"i (elds made (ithout the addition o& the deo+idized &iller material very o&ten have e+cessive %orosity that is not a%%arent on the (eld sur&ace) For this reason autogenous GTA (elds should *e avoided) Other good (elding %ractices to avoid %orosity include a short arc' a*out /)/7 inches 9/)4mm: and am%le (eld metal shielding to e+clude air &rom the molten (eld metal) Argon is the usual shielding gas and %re&erred &or %urging the inside o& %i%es during root %ass (elding) Re%resentative %arameters &or GTAW u!"is are sho(n in Table *. As (ith the other arc (elding %rocesses' the high conductivity' lo(er nic
Bac< to To%
esistance 2elding u!"i alloys (ith 6/2 ore more nic
=ra6ing u!"i alloys are most o&ten *razed (ith silver!*ase *razing alloys) Fillers o& AWS A1)4 lassi&ications BAg!6a' BAg!5' BAg!64 and BAg!1 are ordinarily used) Alloys Bu#!1 and Bu#!7 are acce%ta*le &or use (ith u!"is o& 6/2 or less nic
Flu+es o& the AWS ty%es FB7!A' ' E are satis&actory &or most a%%lications) For &urnace *razing' inert gases' e+ogas' endogas or disassociated ammonia are suita*le) The de( %oint should not e+ceed 5/F 9!.:) For torch *razing' a neutral &lame is used) Brazing clearances o& /)//6 in) to /)//1 in) 9/)/7 mm to /)67 mm: %roduces ma+imum @oint strength and soun dness) Molten *raze alloys may %enetrate and crac< u!"i alloys that are not stress relieved %rior to *razing) Also sur&aces should *e mechanically or chemically cleaned *e&ore *razing) Emery %a%er is usually satis&actory on %i%e and tu*e) Solvents or al
Soldering #re%aration &or soldering is the same as &or *razing) u!"i alloys have good soldera*ility (hen an active chloride ty%e &lu+ is used) It may *e o& the mildly corrosive glutamic acid! hydrochloride ty%e or stronger mi+tures o& zinc' sodium and ammonium chlorides) $ead!tin and tin!antimony solders are used &or u!"i alloys) u!"i alloys are classed as some(hat less soldera*le than *rasses) Bac< to To%
3issimilar etal >oining and 2eld &"erlaing Suggested &iller metal &or @oining u!"i alloys to some o& the commonly com*ined other alloys is sho(n in Table +. The listing is not intended to *e e+clusive in that (elding %rocedures could *e develo%ed using &iller metals not listed) Table +a Filler Metals &or Dissimilar Metal Welds 96885:K (*Note: This is the original 1992 table. See table below for revisions made in 2014) etal to be ?oined to 8A2 and 8TA2 SA2 /UNS0 Comments Cu9Ni /UNS0
Copper !hosphor bron6es All bron6es Carbon steel
ANS2;A2S A.+ ANSI;A2S .( Eu"i 9W0/.61: ERuA6!A5 9.614/: or or EuA6!A5 ERuA6!A5 9064//: 9W0/063: EuSn!A 9W0/164: ERuSn!A 9164//: EuA6!A5 ERu"l 9064//: 9W0/063: ANSI;A2S a.11 ANSI;A2S A.1* E"iu!0 9W4368/: ER"iu!. 9"/3/0/:
#reheat to 6///F 913/: ! ! Steel side may *e
Table +a Filler Metals &or Dissimilar Metal Welds 96885:K (*Note: This is the original 1992 table. See table below for revisions made in 2014) etal to be ?oined to 8A2 and 8TA2 SA2 /UNS0 Comments Cu9Ni /UNS0 overlayed &irst (ith ER"i!6 or ER"iu!. E"i!6 9W45636: ER"i!6 9"/5606: Stainless side may *e Austinetic stainless or or overlayed &irst (ith steels E"irFe!5 ER"ir!7 9"/0/45: ER"i!6 9W40677: Table +b Filler Metals &or Dissimilar Metal Welds (Note: This is the 2014 revised table resented to !"# b$ "avid %ordan& !ons'ltant to the Niel nstit'te) etal to be ?oined to 8A2 and 8TA2 SA2 /UNS0 Cu9Ni /UNS0 A2S A.+ ; A2S .( ; (BS EN ISO 17777 is under =S 'N IS& -*:(: development) ERu"i or ERuAl!A5 ; Eu"i or EuAl!A5 Copper S u .614 or S u 064/ ERuSn!A ; !hosphor bron6es EuSn!A S u 164/A ERuAl!A5 ; Aluminum bron6es EuAl!A5 S u 064/ A2S A.11 ; =S 'N IS& 1*1(-
Carbon steel
E"iu!. ; E "i3/0/
Austinetic stainless E"i!6 or E"irFe!5 ; steels E "i5/06 or E "i0/85
Comments
#reheat to 6///F 913/: ! !
A2S A.1* ; =S 'N IS& 1-(*
ER"iu!. ; S "i3/0/
Steel side may *e overlayed &irst (ith ER"i!6 or ER"iu! .
ER"i!6 or ER"ir! Stainless side may *e 7; overlayed &irst (ith E "i5/06 or S ER"i!6 "i0/45
The ./!7/ u!"i (elds have a limited tolerance &or dilution *y iron) Welds (ith more than a*out 6/2 iron tend to have e+cessive &issures and develo% hot craco(ever' they are not a good choice in (elding to stainless steels *ecause o& limited tolerance &or dilution *y chromium)
O&ten a very use&ul ste% in ma
Cutting u!"i alloys are not amena*le to &lame cutting' *ut %lasma arc cutting and car*on arc cutting (or< (ell) Band sa(s and shears may *e used &or cutting' *ut allo(ances must *e made &or the &act that the alloys are relatively so&t and ductile) >igh!s%eed a*rasive (heels (or< (ell &or *eveling edges and trimming material) Bac< to To%
2elding Cu9Ni Clad Steel !lates The use o& u!"i clad steel %lates o&&ers considera*le material savings in many de signs and a%%lications) An e+am%le is the .0!&oot 951!m: &ishing tra(ler' !oer +ariner ' (ith the hull constructed o& 1;60!in) 94!mm:' 512 ./0// clad) An e+tensive (elding develo%ment %rogram (as underta
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E"i!6' ER"i!6' E"iu!. or ER"iu!. &or the &irst or *arrier %ass &rom the alloy side on to the *ac
#igure -. Ty%ical (eld @oint and *ead se,uence &or u!"i
clad steel %late 96;5! to 7;4!inch or 0)3 to 4)7 mm thic<: •
!ass 1 ! use E"i!6' ER"i!6' "Iiu!.' or ER"iu!. &iller the to% o& the (eld may re,uire grinding to allo( room &or %ass 5
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!ass - ! -se Eu"i or ERu"i
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Bac
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!asses :,*, or as needed ER"i!6' E"iu!.' or ER"iu!. #igure :. Ty%ical (eld @oint and *ead se,uence &or u!"i
clad steel %late' 6;5 inch 965). mm: and thic
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!ass 1, - and : or as needed ! car*on steel &illers such as E./64 or com%ara*le &iller &or GMAW or SAW
Bac
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!ass -A ! Eu"i or ERu"i
A (ide range o& (eld @oint designs and (eld %ass se,uences ha ve *een used &or clad steel (elding) Factors that in&luence the choice include total %late thic
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never let the car*on steel (eld %enetrate the alloy cladding or alloy (eld) Steel (elds (ith co%%er %ic
Bac< to To%
Sheet @ining An alternate to the use o& solid u!"i alloy or clad steel is a%%lying relatively thin sheets to a car*on steel *ac
Other arc s%ot (eld &eatures and controls include •
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The %rocess can *e used on sheet thic
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-sing %ro%er (elding %arameters' (elds have less than a* out 02 iron on the to% sur&ace)
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All sur&aces should *e &ree o& oil' grease' d irt and o+ide scale %rior to arc s%ot (elding)
When arc s%ot GMAW is not %ractical' &or e+am%le *ecause o& (elding %osition or a heavy gage' mid!sheet attachments can *e made *y %lug (elding using %recut holes) The holes may *e circles or slots' e.g.' 6;5!in) 965)3!mm: diameter or 6 in) *y 7;4 in) 951 mm *y 8)1 mm: slots) Round holes in over a*out 7;75!in) 95)3!mm: thic< sheet should have a ta%ered side to avoid side (all lac< o& &usion de&ects) Slot (elds are o&ten easier to (eld' %articularly (hen the (elding is done on vertical sur&aces) In many a%%lications it is also necessary to &illet (eld the edges o& the sheet to the steel *ac
!ipe 2elding u!"i alloy %i%e is (idely used in %i%ing systems &or shi%*oard services' coastal installations' desalination %lants and o&&shore oil %roduction) Small diameter %i%es' 5)/ in) 91/ mm: and under are o&ten soc
#igure *. Automatic or*ital (eld head
(elding u!"i &ire(ater %i%ing Bac< to To%
'#''NC'S 6)
Boundary rac
5) A!./0 u!"i Alloy >ulls the o%%er Mariners E+%erience and Economics Manzolillo' J)$)' Thiele' E)W) and Tuthill' A)>)' Trans S"AME' 6843 968.0:' %3/4) 9Availa*le &rom DA and "iDI): 7)
A Technical #u*lication *y Inco Alloys International' Inc)' "e(ton' ")
3)
o%%er and u!"i lad #lates' #rager' M)' =eay' $)=)' Thiele' Jr)' E)W) Welding Journal' Se%tem*er 68.4)
1)
to the Welding o& u!"i Alloys International "ic
0)
$ining Mild Steel om%onents (ith 8/!6/ u!"i Alloy Sheet Ridge(ay' W)F) and >eath' D)J)' Welding and Metal Fa*rication' Octo*er 6808)
.)
Or*ital #i%e Welding -sed on >ondos Fire(ater System Guilsardo' A)' Dumas' E)' and >enon' B)=)' OFFS>ORE' A%ril 6887)
Bac< to To%
