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Welding Faults

INDEX OF WELDING FAULTS

WELDS ........................................................................ 2-3 WELDING FAULTS ......................................................... 2-3

....................................................................... CRACKS 2-4 CRATER PIPES ....................................................... 2-5 EXCESS PENETRATION BEAD ......................................... 2-6 ROOT CONCAVITY ......................................................... 2-8 SPATTER ..................................................................... 2-9 STRAY ARCING ........................................................... 2-10 SURFACE POROSITY .............................................. 2-11 UNDERCUT ................................................................. 2-12

f

Welding Faults

WELDS

of a well brushed-~n sir.pe coat to the prepared surfate .s strongiy reammendedtoenunddquatepratctt~nandtop~e.entbndg~ng by the coatingsystem Inaddit~on,any wehlmngfaults ofthetyperdwnbed below should beappmpriately recufied M a n y coaurq isapplied

WELDING FAULTS

mefollowirqrettiond~ribervariousfaulninfurion wldsinc~~tIU(tMn steek.Thii is not a tomorehersive amoilatin of all llhiv wldina fauiu

2 only~ewhi~~an&ntpmblems~thtkappi~ananhmati~unlm d r the faulu a n wtified orior to the awropnate surface vreoaratlon and

Phorogmphr within this mim ore~our~p~y oflhe WeMing l m r h in Furion Wefds'by W e a d hbhhing, Cambridge

CRATER PIPES

Welding Faults

M p t i a n : (rater rnuliing hum shrinkage at theend ofaweld run.

kpk All wth poront,n m ~ s t be appoprateiy filled pr~cr to awlrat~on ofa proteitm toat ng lystrm.

Comncc loaungs lalfiy bl age porn m a metal %bnlas an0 i thqdo.tho

Welding Faults

L EXCESS PENETRATION BEAD

Dewiption: Weld metal n~lmally enends below the parent metal surface but th~s IS only a problem when exceniw and

L exceedrthespeuficarlan

Repair: L

Where rharp changes in corncur occur there need to k smoothed to p m n t bridping of the protective coatmg system.

romef~moffiilin~maybe&mrytopreventbridging of the coalinq. Anv undercuts must be appropriately treatedto k t bridging byhecoating system.

Welding Faults

SPATTER

PmbabkCama: Inconect weldinqconditimns,such as t w hiqha weidinq cmmtand/~c&tamm~~ed~onwm~eso~pegaral oni qhlnq ~ loeap lmmns wnhmn tnearc an0 welo poo

Repaim Grind or needk gun off all globules to leave a smooth surface,prior to full surface preparatmon.

Comment: Weld spatter can rarely be ruccessluliy coated and can resulr in prematurecoating breakdown.

Welding Faults

SURFACE POROSITY

kuipth: Pores visibleat the surfaceofaweld.

RobaMeCau~~: Excessive conramination fmm grease. dampness or atmospheric entrainment. Occasionally caused by excessiwrulphur in comumablesor parent metal.

Repair: All wch pororities must h appmprbrely filled pnor to application ofa pmtectiwcoatinq syrtem.

Comment Coating rareb bddge porer in a metal substrate and if theydo,hiscan lead to prematurecoating failure