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154 557 A
200702
Processes
MIG (GMAW) Welding
Guidelines ForGas Metal Arc
Welding (GMAW)
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4-1. E!essi"e #$atter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1%
4-2. &orosit' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1%
4-. In!o$lete *usion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1+
4-4. E!essi"e &enetration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1+
4-%. ,a! / &enetration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1+
4-+. urn roug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17
4-7. Wa"iness / ead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17
4-3. istortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
TAB! "F #"$T!$T%
%!#T&"$ 1 %AF!T' P!#AT&"$% * !A+ B!F"! %&$G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1-1. #'bol 5sage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1-2. Ar! Welding 6aards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1-. Additional #'bols *or Installation8 $eration8 AndMaintenan!e
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-4. 9ali/ornia &ro$osition +% Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-%. &rin!i$al #a/et'#tandards
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
1-+. EM* In/oration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
%!#T&"$ , GA% M!TA A# W!+&$G (GMAW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2-1. '$i!al GMAW #eiautoati! #etu$ Wit 9onstant #$eed*eeder
2-2. '$i!al GMAW #eiautoati! #etu$ Wit Voltage-#ensing*eeder
. . . . . . . . . . . . . . . . . . . . . . . . . . .+
. . . . . . . . . . . . . . . . . . . . . . . . . . .7
2-. '$i!al GMAW &ro!ess 9ontrol #ettings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2-4. 6olding And &ositioning Welding
Gun. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
:
2-%. 9onditions at A//e!t Weld ead#a$e
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2-+. Gun Mo"eent uringWelding
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2-7. &oor Weld ead 9ara!teristi!s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2-3. Good Weld ead 9ara!teristi!s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
2-:. 9oon GMAW #ielding Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
%!#T&"$ - M"+!% "F GMAW TA$%F! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-
-1. #ort 9ir!uit rans/er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
-2. Globular rans/er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
-. #$ra' Ar! rans/er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
%!#T&"$ 4 GMAW W!+&$G T"B!%""T&$G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
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%!#T&"$ 1 %AF!T' P!#AT&"$% * !A+ B!F"! %&$G
A Warning/ Protect 0oursel and ot2ers rom in3ur0 read and ollow t2eserecautions.
so ;oining s'bols.
A Mars a secial saet0message.
o Means Note; not safety
related.
1*,. Arc Welding a8ards
A T2e s0m6ols s2own 6elow are used t2roug2out t2is manualto call attention to and identi0 ossi6le 2a8ards. W2en 0ousee t2e s0m6ol9 watc2 out9 and ollow t2e relatedinstructions to a:oid t2e 2a8ard. T2e saet0 inormationgi:en 6elow is onl0 a summar0 o t2e more comlete saet0inormation ound in t2e %aet0 %tandards listed in %ection
1*5. ead and ollow all %aet0 %tandards.A "nl0 ;ualiied ersons s2ould install9 oerate9 maintain9
and reair t2is unit.
A +uring oeration9 ee e:er06od09 eseciall0 c2ildren9awa0.
!!#T %"#< can ill.
ou!ing li"e ele!tri!al $arts !an !ause /atalso!s or se"ere burns. e ele!trode and wor!ir!uit is ele!tri!all' li"e wene"er te out$ut is on.e in$ut $ower !ir!uit and a!ine internal!ir!uits are also
li"e wen $ower is on. In seiautoati! or autoati! wire welding8te wire8 wire reel8 dri"e roll ousing8 and all etal $arts tou!ingte welding wire are ele!tri!all' li"e. In!orre!tl' installed ori$ro$erl'
grounded e?ui$ent is aaard.
o not tou! li"e ele!tri!al$arts.
Wear dr'8 ole-/ree insulating glo"es and bod'$rote!tion.
Insulate 'oursel/ /ro wor and ground using dr' insulatingats or !o"ers big enoug to $re"ent an' $'si!al !onta!t witte wor or ground.
o not use A9 out$ut in da$ areas8 i/ o"eent is !on/ined8or i/ tere is a danger o/ /alling.
5se A9 out$ut @, i/ re?uired /or te welding $ro!ess.
I/ A9 out$ut is re?uired8 use reote out$ut !ontrol i/ $resenton unit.
Additional sa/et' $re!autions are re?uired wen an' o/te /ollow- ing ele!tri!all' aardous !onditions are$resentB in da$ lo!ations or wile wearing wet !lotingC onetal stru!tures su! as /loors8 gratings8 or s!a//oldsC wen in!ra$ed $ositions su! as sitting8 neeling8 or l'ingC or wentere is a ig ris o/ una"oid- able or a!!idental !onta!t witte wor$ie!e or ground. *or tese !onditions8 use te /ollowinge?ui$ent in order $resentedB 1) a seiautoati! 9 !onstant"oltage (wire) welder8 2) a 9 anual (sti!) welder8 or ) an
A9 welder wit redu!ed o$en-!ir!uit "olt- age. In ostsituations8 use o/ a 98 !onstant "oltage wire welder isre!oended. And8 do not wor alone=
is!onne!t in$ut $ower or sto$ engine be/ore installing orser"i!ing tis e?ui$ent. ,o!out
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is grou$ o/ s'bols eans Warning= Wat! ut=$ossible E,E9DI9 #69F8 MVI@G &AD#8 and 6&AD# aards. 9onsult s'bols and related instru!tions below/or ne!essar' a!tions to a"oid te aards.
urn o// all e?ui$ent wen not in use.
o not use worn8 daaged8 undersied8 or $oorl' s$li!ed !ables.
o not dra$e !ables o"er 'our bod'.
I/ eart grounding o/ te wor$ie!e is re?uired8 ground it
dire!tl' wit a se$arate !able. o not tou! ele!trode i/ 'ou are in !onta!t wit te wor8
ground8 or anoter ele!trode /ro a di//erent a!ine.
o not tou! ele!trode olders !onne!ted to two welding a-!ines at te sae tie sin!e double o$en-!ir!uit "oltage willbe $resent.
5se onl' well-aintained e?ui$ent. De$air or re$la!edaaged $arts at on!e. Maintain unit a!!ording to anual.
Wear a sa/et' arness i/ woring abo"e /loor le"el.
Fee$ all $anels and !o"ers se!urel' in $la!e.
9la$ wor !able wit good etal-to-etal !onta!t towor$ie!e or wortable as near te weld as $ra!ti!al.
Insulate wor !la$ wen not !onne!ted to wor$ie!e to$re"ent !onta!t wit an' etal ob>e!t.
o not !onne!t ore tan one ele!trode or wor !able to an'
single weld out$ut terinal.
%&G$&FA$T +# ="TAG! e>ists in in:erter*t0e welding ower sources ater remo:al o
inut ower. urn // in"erter8 dis!onne!t in$ut $ower8 and dis!arge in$ut
!a$a!itors a!!ording to instru!tions in Maintenan!e#e!tion be/ore tou!ing an' $arts.
FM!% A$+ GA%!% can 6e2a8ardous.
Welding $rodu!es /ues and gases. reatingtese /ues and gases !an be aardous to 'ourealt.
Fee$ 'our ead out o/ te /ues. o not breate te /ues.
I/ inside8 "entilate te area and
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A# A'% can 6urn e0es and sin.
Ar! ra's /ro te welding $ro!ess $rodu!eintense "isible and in"isible (ultra"iolet andin/rared) ra's tat !an burn e'es and sin. #$ars/l o// /ro te
B&+P "F GA% can in3ure or ill.
#ut o// sielding gas su$$l' wen not in use.
Alwa's "entilate !on/ined s$a!es oruse a$$ro"ed air-su$$lied res$irator.
&a!eaer wearers ee$ awa'.
Wearers sould !onsult teir do!torbe/ore going near ar! welding8 gouging8
F'&$G M!TA can in3ure e0es.
Welding8 !i$$ing8 wire brusing8 andgrinding !ause s$ars and /l'ing etal. Aswelds !ool8 te' !an trow o// slag.
weld.
Wear an a$$ro"ed welding elet /itted wit a $ro$er sade o//il- ter lenses to $rote!t 'our /a!e and e'es wen welding orwat!ing (see A@#I 4:.1 and 37.1 listed in #a/et'#tandards).
Wear a$$ro"ed sa/et' glasses wit side sields under
'our elet. 5se $rote!ti"e s!reens or barriers to $rote!t oters /ro
/las8 glare and s$arsC warn oters not to wat! te ar!.
Wear $rote!ti"e !loting ade /ro durable8 /lae-resistantate- rial (leater8 ea"' !otton8 or wool) and /oot $rote!tion.
"T PAT% can cause se:ere 6urns.
o not tou! ot $arts bare anded.
Allow !ooling $eriod be/ore woring on gunor tor!.
o andle ot $arts8 use $ro$er toolsandlode i damaged.
#ielding gas !'linders !ontain gas underig $ressure. I/ daaged8 a !'linder !an e$lode.#in!e gas !'linders are norall' $art o/ tewelding $ro!ess8 be sure to treat te !are/ull'.
&rote!t !o$ressed gas !'linders /ro e!essi"e eat8
e!ani- !al so!s8 $'si!al daage8 slag8 o$en /laes8s$ars8 and ar!s.
Install !'linders in an u$rigt $osition b' se!uring to astationar' su$$ort or !'linder ra! to $re"ent /alling or ti$$ing.
Fee$ !'linders awa' /ro an' welding or oter ele!tri!al !ir!uits.
@e"er dra$e a welding tor! o"er a gas !'linder.
@e"er allow a welding ele!trode to tou! an' !'linder.
@e"er weld on a $ressuried !'linder e$losion will result.
5se onl' !orre!t sielding gas !'linders8 regulators8 oses8 and/it- tings designed /or te s$e!i/i! a$$li!ationC aintain teand asso!iated $arts in good !ondition.
urn /a!e awa' /ro "al"e outlet wen o$ening !'linder "al"e.
Fee$ $rote!ti"e !a$ in $la!e o"er "al"e e!e$t wen !'linder isin use or !onne!ted /or use.
5se te rigt e?ui$ent8 !orre!t $ro!edures8 and su//i!ientnu- ber o/ $ersons to li/t and o"e !'linders.
Dead and /ollow instru!tions on !o$ressed gas!'linders8 asso!iated e?ui$ent8 and 9o$ressed Gas
Asso!iation (9GA) $ubli!ation &-1 listed in #a/et' #tandards.
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1*-. Additional %0m6ols For &nstallation9 "eration9 And Maintenance
F&! " !?P"%&"$ 2a8ard.
o not install or $la!e unit on8 o"er8 ornear !obustible sur/a!es.
o not install unit near /laables.
o not o"erload building wiring be sure $ower su$$l' s'steis $ro$erl' sied8 rated8 and $rote!ted to andle tis unit.
FA&$G $&T can cause in3ur0.
5se li/ting e'e to li/t unit onl'8 @running gear8 gas !'linders8 or an' otera!!essories.
5se e?ui$ent o/ ade?uate !a$a!it' to li/tand su$$ort unit.
I/ using li/t /ors to o"e unit8 be sure /orsare long enoug to etend be'ond o$$ositeside o/ unit.
M"=&$G PAT% can cause in3ur0.
Fee$ awa' /ro o"ing $arts su! as /ans.
Fee$ all doors8 $anels8 !o"ers8 andguards !losed and se!urel' in $la!e.
6a"e onl' ?uali/ied $ersons reo"edoors8 $anels8 !o"ers8 or guards /oraintenan!e as ne!essar'.
Deinstall doors8 $anels8 !o"ers8 orguards wen aintenan!e is /inised andbe/ore re- !onne!ting in$ut $ower.
!A+ &$%T#T&"$%.
Dead wners Manual be/ore using orser"i!- ing unit.
5se onl' genuine Miller
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1%4 %%7 &age
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1*5. Princial %aet0 %tandards
Safety in Welding, Cutting, and Allied Processes, A@#I #tandard4:.18 /ro Global Engineering o!uents ($oneB 1-377-41-%1348websiteBww w .global.is.!o).
Recommended Safe Practices for the Prearation for Welding andCut! ting of Containers and Piing8 Aeri!an Welding #o!iet'#tandard AW# *4.1 /ro Global Engineering o!uents($oneB1-377-41-%1348 websiteBww w .global. is.!o).
National "lectrical Code8 @*&A #tandard 708 /ro @ational *ire&rote!- tion Asso!iation8 &.. o :1018 1 atter' Mar! &ar8Huin!'8 MA022+::101 ($oneB +177700008 websiteBww w .n/$a.org).
Safe #andling of Comressed $ases in Cylinders8 9GA &a$let &-18 /ro 9o$ressed Gas Asso!iation8 17% e//erson a"is6igwa'8 #uite 10048 Arlington8 VA 222024102 ($oneB 704120:008 web- siteBww w .!ganet.!o).
Code for Safety in Welding and Cutting8 9#A #tandard W117.28/ro9anadian #tandards Asso!iation8 #tandards #ales8 173Dedale
oule"ard8 Dedale8 ntario8 9anada M:W 1D($oneB3004++727 or in oronto 41+74740448 websiteB ww w .!sain- ternational.org).
Practice %or &ccuational And "ducational "ye And %aceProtection,
A@#I #tandard 37.18 /ro Aeri!an @ational #tandards Institute811West 42nd #treet8 @ew or8 @ 100+3002 ($oneB 212+42
4:008 websiteBww w .ansi.org).
Standard for %ire Pre'ention (uring Welding, Cutting, and &ther#ot Wor)8 @*&A #tandard %18 /ro @ational *ire &rote!tion
Asso!iation8 &.. o :1018 1 atter' Mar! &ar8 Huin!'8 MA022+::101 ($oneB+177700008websiteBww w .n/$a.org).
#6A8 !!u$ational #a/et' and 6ealt #tandards /or GeneralIndus- tr'8 itle 2:8 9ode o/ *ederal Degulations (9*D)8 &art 1:108#ub$art H8 and &art 1:2+8 #ub$art 8 /ro 5.#. Go"ernent &rinting//i!e8 #u$er- intendent o/ o!uents8 &.. o 71:%48 &ittsburg8&A 1%2%0 (tere are 10 Degional //i!es$one /or Degion%8 9i!ago8 is12%22208websiteBww w .osa.go").
1*@. !MF &normation9onsiderations About Welding And e E//e!ts / ,ow *re?uen!'Ele!tri! And Magneti! *ields
Welding !urrent8 as it /lows troug welding !ables8 will !auseele!tro- agneti! /ields. ere as been and still is soe !on!ernabout su! /ields. 6owe"er8 a/ter eaining ore tan %00 studiess$anning 17 'ears o/ resear!8 a s$e!ial blue ribbon !oittee o/te @ational Desear! 9oun!il !on!luded tatB Je bod' o/e"iden!e8 in te !oittees >udgent8 as not deonstrated tate$osure to $ower- /re?uen!' ele!tri! and agneti! /ields is auan-ealt aard.K 6owe"er8 studies are still going /ort ande"iden!e !ontinues to be eained. 5ntil te /inal !on!lusions o/te resear! are rea!ed8 'ou a' wis to iniie 'our e$osureto ele!troagneti! /ields wen welding or !utting.
o redu!e agneti! /ields in te wor$la!e8 use te /ollowing$ro!eduresB
1. Fee$ !ables !lose togeter b' twisting or ta$ingte.
2. Arrange !ables to one side and awa' /ro teo$erator.
. o not !oil or dra$e !ables around 'ourbod'.
4. Fee$ welding $ower sour!e and !ables as /ar awa' /ro
o$era- tor as $ra!ti!al.
%. 9onne!t wor !la$ to wor$ie!e as !lose to te weld as
$ossi- ble.
A6out Pacemaers/
&a!eaer wearers !onsult 'our do!tor be/ore welding or goingnear welding o$erations. I/ !leared b' 'our do!tor8 ten /ollowing teabo"e $ro!edures is re!oended.
http://www.global.ihs.com/http://www.global.ihs.com/http://www.global.ihs.com/http://www.nfpa.org/http://www.cganet.com/http://www.cganet.com/http://www.csa/http://www.ansi.org/http://www.ansi.org/http://www.nfpa.org/http://www.nfpa.org/http://www.osha.gov/http://www.osha.gov/http://www.global.ihs.com/http://www.global.ihs.com/http://www.nfpa.org/http://www.cganet.com/http://www.csa/http://www.ansi.org/http://www.nfpa.org/http://www.osha.gov/8/10/2019 Miller Guide for Gmaw New
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1%4 %%7 &age 4
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%!#T&"$ , GA% M!TA A# W!+&$G (GMAW)
Gas Metal Ar! Welding (GMAW) is a welding $ro!ess wi! >oins etals b' eating te etals to teir elting$oint wit an ele!tri! ar!. e ar! is between a !ontinuous8 !onsuable ele!trode wire and te etal beingwelded. e ar! is sielded /ro !ontainants in te atos$ere b' a sielding gas.
GMAW !an be done in tree di//erent wa'sB
#eiautoati! Welding - e?ui$ent !ontrols onl' te ele!trode wire /eeding. Mo"eent o/ welding gun is
!ontrolled b' and. is a' be !alled and-eld welding.
Ma!ine Welding - uses a gun tat is !onne!ted to a ani$ulator o/ soe ind (not and-eld). An o$erator asto !onstantl' set and ad>ust !ontrols tat o"e te ani$ulator.
Autoati! Welding - uses e?ui$ent wi! welds witout te !onstant ad>usting o/ !ontrols b' a welder oro$erator. n soe e?ui$ent8 autoati! sensing de"i!es !ontrol te !orre!t gun alignent in a weld >oint.
asi! e?ui$ent /or a t'$i!al GMAW seiautoati! setu$B
Welding &ower #our!e - $ro"ides welding $ower.
Wire *eeders (9onstant #$eed And Voltage-#ensing) - !ontrols su$$l' o/ wire to welding gun.
9onstant #$eed *eeder - 5sed onl' wit a !onstant "oltage (9V) $ower sour!e. is t'$e o/ /eeder as a
!ontrol !able tat will !onne!t to te $ower sour!e. e !ontrol !able su$$lies $ower to te /eeder and allows te!a$abilit' o/ reote "oltage !ontrol wit !ertain $ower sour!e
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,*1. T0ical GMAW %emiautomatic %etu Wit2 #onstant %eed Feeder
1 9onstant Voltage(9V) Welding &ower#our!e
2 9onta!tor 9ontrol
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,*,. T0ical GMAW %emiautomatic %etu Wit2 =oltage*%ensing Feeder
1 9onstant 9urrent (99-9)r 9ontstant Voltage (9V)Welding &ower #our!e
2 Weld 9able o *eeder
Ground 9able o Wor$ie!e
4 Wor$ie!e
% Voltage-#ensing 9la$
+ Welding Gun
7 Gun rigger De!e$ta!le
3 Voltage-#ensing Wire *eeder
: Gas 6ose
10 #ielding Gas 9'linder
1
10
2
:
3
7
4%
+
De/. 304 000-9
1%4 %%7 &age 7
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,*-. T0ical GMAW Process #ontrol %ettings
11
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,*4. olding And Positioning Welding Gun
o Welding +ire is energi2ed+hen gun trigger is ressed.3efore lo+ering helmet and
ressing trigger, -e sure +ireis no more than 456 in 47 mm/
ast end of
1no22le, and ti of +ire is osi!tioned correctly on seam.
1 6old Gun And 9ontrol Gunrigger
2 Wor$ie!e
2
Wor 9la$
4 Ele!trode Etension (#ti!out)1
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,*5. #onditions T2at Aect Weld Bead %2ae
1
10
2
10
+
o Weld -ead shae deendson gun angle, direction oftra'el, electrode e8tensionstic)out/, tra'el seed,thic)ness of -ase metal, +irefeed seed +eld current/,and 'oltage.
Gun Angles And Weld Bead
Proiles
1 &us
2 &er$endi!ular
rag
!lectrode !>tensions (%ticout)
4 #ort
% @oral
+ ,ong
Fillet Weld !lectrode !>tension(%ticout)
7 #ort
3 @oral
: ,ong4 % Gun Tra:el %eed
10 #low
11 @oral
12 *ast
7 3 :
10 11 12
#-0+4-A
1%4 %%7 &age 10
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,*@. Gun Mo:ement +uring Welding
o Normally, a single stringer-ead is satisfactory for mostnarro+ groo'e +eld oints.#o+e'er, for +ide groo'e +eld
oints or -ridg! ing across gas,a +ea'e -ead or multilestringer -eads +or)s
1 2-etter.
1 #tringer ead #tead' Mo"e-ent Along #ea
2 Wea"e ead #ide o #ideMo"eent Along #ea
Wea"e &atterns
5se wea"e $atterns to !o"er awide area in one $ass o/ teele!trode.
#-00%4-A
,*7. Poor Weld Bead #2aracteristics
1 ,arge #$atter e$osits2 Doug8 5ne"en ead
#ligt 9rater uring Welding
4 ad "erla$
% &oor &enetration
1
2 4
%
#-00%-A
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1%4 %%7 &age 11
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,*C. Good Weld Bead #2aracteristics
1
2 4%
1 *ine #$atter
2 5ni/or ead
Moderate 9rateruring
Welding
Weld a new bead or la'er /or ea!1
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%!#T&"$ - M"+!% "F GMAW TA$%F!
$"T! $MAW transfer mode is determined -y 'aria-les such as shielding gas tye, arc'oltage, arc current, diameter of electrode and +ire feed seed.
-*1. %2ort #ircuit Transer
1 #ort 9ir!uit rans/er
#ort !ir!uit trans/er re/ers tote welding wire a!tuall' Jsort!ir!uit- ingK (tou!ing) te baseetal be- tween :0 - 200 ties $erse!ond.
1Wit sort !ir!uit trans/er8 wire /eeds$eeds8 "oltages8 and de$ositionrates are usuall' lower tan witot- er t'$es o/ etal trans/er su!as s$ra' trans/er. is aes sort!ir- !uit trans/er "er' "ersatileallowing te welder to weld on tinor ti! etals in an' $osition.
,iitations o/ sort !ir!uit trans/erB
A relati"el' low de$osition rate
,a! o/ /usion on ti!er etals
More s$atter
o Short circuit transfer usuallyhas a crac)ling -acon frying/sound +hen a good conditione8ists.
2 #ort 9ir!uit 9'!le
A - Ele!trode is sort !ir!uited tobase etal. @o ar!8 and !urrentis /lowing troug ele!trodewire and base etal.
2 - Desistan!e in!reases in ele!-trode wire !ausing it to eat8
elt and Jne! downK.9 - Ele!trode wire se$arates /ro
weld $uddle8 !reating an ar!.#all $ortion o/ ele!trode wireis de$osited wi! /ors aweld $uddle.
- Ar! lengt and load "oltage areat aiu. 6eat o/ ar! is/lat- tening te $uddle andin!reas- ing te diaeter ti$ o/ele!- trode.
E - Wire /eed s$eed o"er!oeseat o/ ar! and wirea$$roa!es base etal again.
* - Ar! is o// and te sort!ir!uit !'!le starts again.
De/. 304 37:-A
1%4 %%7 &age 1
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-*,. Glo6ular Transer
1 Globular rans/er
Globular trans/er re/ers to te stateo/ trans/er between sort-!ir!uitingand s$ra' ar! trans/er. ,argeglobs o/ wire are e$elled o// teend o/ te
1 ele!trode wire and enter teweld $uddle.
Globular trans/er !an resultwen welding $araeters su! as"oltage8 a$erage and wire /eeds$eed are soewat iger tante settings /or sort !ir!uittrans/er.
,iitations o/ globular trans/erB
&resen!e o/ s$atter
,ess desirable weld a$$earan!etan s$ra' ar! trans/er
Welding is liited to /lat$ositions and oriontall' /illetwelds
Welding is liited to etal 1
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1%4 %%7 &age 14
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%!#T&"$ 4 GMAW W!+&$G T"B!%""T&$G
4*1. !>cessi:e %atter
E!essi"e #$atter s!atteringo/ olten etal $arti!les tat !oolto solid /or near weld bead.
Possi6le #auses #orrecti:e Actions
Wire /eed s$eed too ig. #ele!t lower wire /eed s$eed.
Voltage too ig. #ele!t lower "oltage range.
Ele!trode etension (sti!out) too long. 5se sorter ele!trode etension (sti!out).
Wor$ie!e dirt'. Deo"e all grease8 oil8 oisture8 rust8 $aint8 under!oating8 and dirt /ro wor sur/a!e be/ore welding.
Insu//i!ient sielding gas at welding
ar!.
In!rease /low o/ sielding gas at regulator
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4*-. &ncomlete Fusion
In!o$lete *usion /ailure o/weld etal to /use !o$letel' witbase etal or a $re!eeding weldbead.
Possi6le #auses #orrecti:e Actions
Wor$ie!e dirt'. Deo"e all grease8 oil8 oisture8 rust8 $aint8 !oatings8 and dirt /ro wor sur/a!e be/ore welding.
Insu//i!ient eat in$ut. #ele!t iger "oltage range andust wire /eed s$eed.
I$ro$er welding te!ni?ue. &la!e stringer bead in $ro$er lo!ation(s) at >oint during welding.
Ad>ust wor angle or widen groo"e to a!!ess botto during welding.
Moentaril' old ar! on groo"e side walls wen using wea"ing te!ni?ue.
Fee$ ar! on leading edge o/ weld $uddle.
5se !orre!t gun angle o/ 0 to 1% degrees.
4*4. !>cessi:e Penetration
E!essi"e &enetration weldetal elting troug baseetal and anging underneatweld.
Possi6le #auses #orrecti:e Actions
E!essi"e eat in$ut. #ele!t lower "oltage range and redu!e wire /eed s$eed.
In!rease tra"el s$eed.
4*5. ac " Penetration
,a! / &enetration sallow/usion between weld etal andbase etal.
,a! o/ &enetration Good &enetrationPossi6le #auses #orrecti:e Actions
I$ro$er >oint $re$aration. Material too ti!. oint $re$aration and design ust $ro"ide a!!ess to botto o/ groo"e wile
ain- taining $ro$er welding wire etension and ar! !ara!teristi!s.
I$ro$er weld te!ni?ue. Maintain noral gun angle o/ 0 to 1% degrees to a!ie"e aiu $enetration.
Fee$ ar! on leading edge o/ weld $uddle.
e sure welding wire etends not ore tan 1
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4*@. Burn T2roug2
urn-roug weld etalelting !o$letel' troug baseetal resulting in oles were noetal re- ains.
Possi6le #auses #orrecti:e Actions
E!essi"e eat in$ut. #ele!t lower "oltage range and redu!e wire /eed s$eed.
In!rease and
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Miller !lectric Mg. #o.An Illinois ool Wors 9o$an'
1+% West #$en!er #treet
A$$leton8 WI %4:14 5#A
&nternational ead;uarters%A
5#A &oneB :20-7%-4%0% Auto-Atten
5#A 9anada *APB :20-7%-414
International *APB :20-7%-412%
!uroean ead;uarters nited