IntroductionofSAWweldingPrincipleofSAWmethodThefluxshouldcompletelycoverthearc.Thestickoutisapproximately30mm,butcaninsomecasesbeconsiderablymore.Stick-outSubmergedArcWelding(SAW)HighProductivity -Highamperageispossible -DeslaggingiseasyHighQuality -Deeppenetration -ExcellentmechanicalpropertiesGoodEnvironment -Verylittlefume -EasyoperationRangeofapplicationPlatethicknessandedgepreparationUseI-jointsforplatethicknessabout2-12mmUseY-jointsordoubleY-jointsabove12mmThejointmustbeaccuratelycut.Gaps,ifany,mustnotexceed1mm.Thejointshouldhaveaproperbottomsection,consistingeitherofparentmaterial,abackingbarorhandweldedrootbeadtowithstandthedeeppenetrationwhichistypicalforSubmergedArcWeldingExamplesofSAWmachinesImportantwhenweldingSAWTheplateshavetobestraight.Theplateshavetobeclean,preferablygroundorshotblasted.Thepositioningofthewireisofgreatestimportance.Thefluxshouldcoverthearccompletely

(notnecessarilycoverthewirecompletely)Thefluxshouldbedry.ProductivitycomparisonThereareseveralwaystoincreaseproductivityfurther,relativetosinglewireonly:Twin-arc:Weldingwithtwowiresandone powersource.Tandem: Weldingwithtwowiresandtwo powersources.Grain: Weldingwiththeadditionof metalpowder.Coldwire:Weldingwiththeadditionof

coldwire.Twin-arcwelding

DCpowersource+

-Twin-arcweldingParallelpower-50%greaterdepositionrateTandemButts&FilletsSidebysideSkewedCladdingAvoidsburnthroughA6TwinarcA6SW/TwinArcKitTandemarcWelding

ACpowersource

DCpowersource+-

Directionofwelding~30mmTandemarcWeldingSinglepool-HighestdepositionrateTwinpool-TravelspeedlimitedbyundercutVeryresistanttoporosityandcracks

A6TandemSubarcIronPowderfeedunitHighlyincreasedweldingspeedanddepositionrateReductionofdilutionfromparentmetalgivinghigherimpactstrengthEasilyfittedtostandardA2/A6weldingequipmentIronPowderFeedUnitSynergiccoldwirekit(SCW)ProductivitycomparisonISOjointwithOK10.71fluxandOK12.22wire(3.0mmhotand2.0mmcold)500A,32-33Vand33m/h.3mm DC+ 20beads3+2mmDC+ 13beads3mm AC 18beads3+2mm AC 12beadsProductivitycomparisonWeldingmethod Speedincm/minfora 9mmbuttjointManualMetalArc(MMA) 10-11Semi-AutomaticFCW 25SinglewireSAW 45TwinwireSAW 53DepositionratewithSAWThedepositionrateisshownasafunctionofwirediameterandamperage.2004006008001000AmpKg/h161412108642abefgcdWirediametera=1,6mmb=2,0mmc=2,4mmd=3,2mme=4,0mmf=5,0mmg=6,0mmDepositionratewithSAW

Recommendedcurrentrangeanddepositionrates(Kg/h)fordifferentwirediametersFluxconsumptionkg/mWeldingspeedinm/h

0,40,300,10,2408060100160140120InfluenceofAmperageandVoltageHigheramperagegivesdeeperpenetrationHighervoltagegiveswiderpenetration.Thearclengthgetsextended.Influenceofelectricalstick-out

Longerstick-outgiveshigherdepositionrate,butalsomoreshallowpenetration.Above:Penetrationatdifferentstick-outRight:Depositionrateatdifferentstick-outs.A:25mmB:57mmC:83mmInfluenceofpolarityandwirediameterDeepestpenetrationwithpositiveelectrode.Normally,theweldingmachineisequippedwithDCpositiveelectrode.Atconstantamperage,thepenetrationgetsdeeperwithsmallerwirediameter,duetothehighercurrentdensity.Influenceofwireangle

Thewireangleinfluencesbothpenetration,theweldconvexity,andthetendencytoundercutting. Backhandgiveshighpenetration,narrowandhighweldconvexity,andrelativelyhighriskforundercutting.Verticalweldinggivesnormal values.Forehandgiveslowpenetration,

wideandlowweldconvexity, andrelativelyslightriskfor undercutting.BackhandVerticalForehandExamplesofincorrectweldjoints

Weldingwithtoohi