arc welding notes - reed high metalworking弧焊笔记-里德高金属加工

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1、ARCWELDINGNOTESARCWELDING–ShieldedMetalArcWelding(SMAW).Electricity,asitjumpsagaseousgapbetweentwoconductors.Producesanarcasintenseas9000°F.TYPEsOFWELDERSRectifierD.C.(DirectCurrent)–ElectricityisconvertedfromA.C.(AlternatingCurrent)throughtransformers

2、andrectifiers.A.C./D.C.–DualpurposeELECTRODESUsually14”long-1-Classification–BrandnamesdifferbuttheA.W.S.numbersystemisthestandard:Example=E6013=EXXXXE=Electrode60=TensilestrengthX1000psi1=Rodposition(1=all,2=horizontalorflat,3=flatonly)3=Dealercharact

3、eristics–polarity,application,flux,composition,etc.A.FIVEFUNCTIONSOFFLUX/SLAG1.Cleansmetalofoxides2.Stabilizesthearc3.Keepsoxygenaway4.Formstheweld5.LetstheweldcoolslowlyPOLARITIES1.Directcurrentstraightpolarity–(D.C.S.P.)2.DirectCurrentReversePolarity

4、–(D.C.R.P.)DCRPflowsinonedirectionalso(-to+)buttheleadsarereversed.1/3heatatthebaseand2/3heatattherod.Characteristics1.Deeppenetration–goodforthickmetals2.Pronetoarcblow3.AlternatingCurrent-(A.C.)STRIKINGANARC–Likestrikingamatch–touchtheelectrodetothem

5、etal,thencircleupandbackdowntothedia.oftherodawayfromthebasemetal.Motion-(Avoidexcessivemovement)A.Straight-Feedin&dragthepuddleRODPOSITIONFlat–Rodperpendiculartobasemetal.Inclineabout20°fromperpendiculartowarddirectionoftravel.Dragtheweld.(Backhand)La

6、pporInsideCorner–Anglerod30°to45°tobasemetal.Incline20°towarddirectionoftravel.Dragweld.WELDJOINTSButtjoint–preparejoint.Metalmustbeclean.Alwaystack&veethickpiecesforpenetration.Useaslightmotionback&forth.Flange(edgejoint)–Alwaystack.Easiestweld.Thickp

7、iecesshouldbeveed.Lappjoint–Verycommon.Plug,rosette,slotweldsareallvariationsofthelapweld.Concentrateheatonbottomplate.Useaslightweavemotion.Alwaystack.InsideCorner(Teejoint)–Equalweldoneachplate.Finishedjointshouldbeconcavetoflat.Useaclosearc.Concentr

8、ateheatonbottomplate.Alwaystack.Outsidejoint–Allowfornaturalvee.Alwaystack.Useaslightweave.WELDINGPOSITIONSFlatHorizontal(onaverticalplane).VerticalOverheadPROBLEMSArcBlow–Amagneticforcedeflectstheweldintosplitting.Cure–Reestablishgroun