RG1.043 低合金钢部件的不锈钢堆焊控制 1973

GeneralDesignCriterionI.QualityStandardsandRecords,ofAppendixAto10CFRPart50,GeneralDesignCriteriaforNuclearPowerPlants,requiresthatcomponentsimportanttosafetybedesigned,fabricated,andtestedtoqualitystandardscommensuratewiththeimportanceofthesafetyfunctiontobeperformed.AppendixBto10CFRPart50,QualityAssuranceCriteriaforNuclearPowerPlantsandFuelProcessingPlants,requiresthatmeasuresbeestablishedtoassurecontrolof'specialprocessessuchasweldingandthatpropertestingbeperformed.Thisguidedescribesacceptablemethodsofimplementingtheserequirementswithregardtotheselectionandcontrolofweldingprocessesusedforcladdingferriticsteelcomponentswithausteniticstainlesssteeltorestrictpracticesthatcouldresultinundercladcracking.Thisguideislimitedtoforgingsandplatematerialanddoesnotapplytootherproductformssuchascastingsandpipe.Adequateresistancetoundercladcrackingfortheselatteritemsshouldbeassuredonacase-by-casebasis.Thisguideappliestolight-water-cooledreactors.TheAdvisoryCommitteeonReactorSafeguardshasbeenconsultedconcerningthisguideandhasconcurredintheregulatoryposition.,B..DISCUSSIONThepresenceofintergranularcrackinginlow-alloysteelunderstainlesssteelweldcladdinghasbeenobserved''2inreactorvesselsandothercomponentsfor'WestinghouseNuclearEnergySystemsReportWCAP7733ReactorVesselsWeldCladding-BaseMetalInteraction,byT.R.Mager,et.al.,April1971.2OakRidgeNationalLaboratory,HeavySectionSteelTechnologyProgram,6thAnnualInformationMeeting,April25-26,1972,PaperNo.5,PVRCTaskGroupReportonUnder-CladCracking,byR.D.Wylie,SouthwestResearchInstitute.May1973UIDEnuclearsystemsinvaryingdegreesdependingonthematerialandthecladdingprocesses.Thisconditionhasbeenreproducedexperimentally3usingspecificmaterialsandweldingprocessescommontothereactorcomponents.Undercladcrackinghasbeen:reportedonlyinforgingsandplate:materialofSA-508Class2composition4madetocoarse-grainpracticewhencladusinghigh-deposition-rateweldingprocessesidentifiedashigh-heat-inputprocessessuchasthesubmerged-arcwide-stripandthesubmerged-arc6-wireprocesses.CrackingwasnotobservedinSA-508Class2materialscladbylow-heat-inputprocessescontrolled.tominimizeheatingofthebasemetal.Further,crackingwasnotobservedincladSA-533GradeBClassIplatematerial,whichisproducedtofine-grainpractice;regardlessoftheweldingprocessused.Characteristically,thecrackingoccursonlyinthegrain-coarsenedregionofthebasemetalheat-affectedzoneattheweldbeadoverlap.Thesubsurface.locationandsizeofthesecracks(0.5in.x0.165in.maximum)makethemrelativelyinsensitivetodetectionusingstandardnondestructiveexaminationmethods.Detectionnormallyrequiresdestructivelyremovingthecladdingtotheweldfusionline.andexaminingtheexposedbasemetaleitherbymetallographictechniquesorwithliquidpenetrantormagneticparticletestingmethods.'BabcockandWilcoxNuclearPowerGenerationReportB&W10013StudyoflntergranularSeparationsinLow-AlloySteelHeatAffectedZonesUnderAusteniticStainlessSteelWeldCladding,byP.S.Ayres,et.al.,December1971.4SA-508,SpecificationforQuenchedandTemperedVacuumTreatedCarbonandAlloySteelForgingsforPressureVessels,doesnotcoverplate.However,platewithcompositionsimilartoSA-508Class2hasbeenreportedtohaveundercladcracking.USAECREGULATORYGUIDEScopiesofpbAadpiiiemaybeobtainedbyrequestindicatingthedivisionsdesiredtotheUS.AeomtInerllyCommission.Wsahington,D.C..20545,RegulatoryGuidesareissuedtodescribeandmakeAvailabletothepublicAttention:DlsctarofReulatorVStandards.CommentsAndsuggestionsformethodsacceptabletotheAECRegulatorystaffofimplementingspecificpartsofimprovementsintheoeguideswoencouragedandAhouldbesenttotheSecretarytheCommission'sregulations,todelineatetechniquesusedbythestaffinoftheCommission.US.AtomicEnerwComenslon.Wmhington,D.C.20645.evaluatingspecificproblemsorpostulatedaccidents,ortoprovideguidancetoAttention:Chief,PublicProceedingsStaff.elplicents.RegulatoryGuidesArenotsubstitutesforregulationsandcompliancewiththemisnotrequired.MethodsandsolutionsdifferentfromthosesetoutinTheguidesere'ueuadinthefollowingtenbroaddivisions:theguideswillbeacceptableiftheyprovideabasisforthefindingsrequisitetotheissuanceorcontinuanceofapermitorlicensebytheCommission.1.PowerReactors61.Protlucts2.ResserdtaodTestReactors7.Transportation3.FuelsAndMateiasFalclitlesS.OccupationalHealthPublishedguideswillberevisedperiodically,asappropriate,toAccommodate4.EnvironmentalandSiting9.AntitrustReviewcommentsandtoreflectnewinformationorexperience.5.MateriskandPlanaFPratWle10.GeneralU.S.ATOMICENERGYCOMMISSIONREGULATORYC3DIRECTORATEOFREGULATORYSTANDARDSREGULATORYGUIDE1.43CONTROLOFSTAINLESSSTEELWELDCLADDINGOFLOW-ALLOYSTEELCOMPONENTSA.INTRODUCTIONFromtheresultsof'certainanalyticalevaluations.Ithasocinconcludedthatcracksofthisnaturewillhavenodetrimentaleffectonthestructuralintegrityofcompoinx..:tsunderoperatingconditions.However,becauseruncertaintiescxistconcerningassurinptionsihade-'...intheýeanalysesitswellasconcerringthecombinederfectsoifstraincoiicentration.andcyclic'loadingoncrackgiowth.thepresenceofthesecracksisundesirable,andtheyshouldbeavoidedtotheextentpractical.Accordingly,fabricationproc