射线检测中焊接缺陷图片.doc

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1、GeneralWeldingDiscontinuitiesThefollowingdiscontinuitiesaretypicalofalltypesofwelding.Coldlapisaconditionwheretheweldfillermetaldoesnotproperlyfusewiththebasemetalorthepreviousweldpassmaterial(interpasscoldlap).Thearcdoesnotmeltthebasemetalsufficientlyandcausestheslightlymoltenpuddletoflowintob

2、asematerialwithoutbonding.Porosity（气孔）istheresultofgasentrapmentinthesolidifyingmetal.Porositycantakemanyshapesonaradiographbutoftenappearsasdarkroundorirregularspotsorspecksappearingsingularly,inclustersorrows.SometimesporosityiselongatedandmayhavetheappearanceofhavingatailThisistheresultofgas

3、attemptingtoescapewhilethemetalisstillinaliquidstateandiscalledwormholeporosity.Allporosityisavoidinthematerialitwillhavearadiographicdensitymorethanthesurroundingarea.Clusterporosity（密集气孔）iscausedwhenfluxcoatedelectrodesarecontaminatedwithmoisture.Themoistureturnsintogaseswhenheatedandbecomest

4、rappedintheweldduringtheweldingprocess.Clusterporosityappearjustlikeregularporosityintheradiographbuttheindicationswillbegroupedclosetogether.Slaginclusions（夹渣）arenonmetallicsolidmaterialentrappedinweldmetalorbetweenweldandbasemetal.Inaradiograph,dark,jaggedasymmetricalshapeswithintheweldoralon

5、gtheweldjointareasareindicativeofslaginclusions.Incompletepenetration(IP)orlackofpenetration(LOP)（未焊透）occurswhentheweldmetalfailstopenetratethejoint.Itisoneofthemostobjectionablewelddiscontinuities.Lackofpenetrationallowsanaturalstressriserfromwhichacrackmaypropagate.Theappearanceonaradiographi

6、sadarkareawithwell-defined,straightedgesthatfollowsthelandorrootfacedownthecenteroftheweldment.Incompletefusion（未融合）isaconditionwheretheweldfillermetaldoesnotproperlyfusewiththebasemetal.Appearanceonradiograph:usuallyappearsasadarklineorlinesorientedinthedirectionoftheweldseamalongtheweldprepar

7、ationorjoiningarea.Internalconcavityorsuckback（内凹）isconditionwheretheweldmetalhascontractedasitcoolsandhasbeendrawnupintotherootoftheweld.Onaradiographitlookssimilartolackofpenetrationbutthelinehasirregularedgesanditisoftenquitewi