RG1.034 电渣焊接焊接特性控制 1972

12/28/72U.S.ATOMICENERGYCOMMISSIONREGULATORYGUIDEDIRECTORATEOFREGULATORYSTANDARDSREGULATORYGUIDE1.34CONTROLOFELECTROSLAGWELDPROPERTIESA.INTRODUCTIONGeneralDesignCriterion1,QualityStandardsandRecords,ofAppendixAto10CFRPart50,GeneralDesignCriteriaforNuclearPowerPlants,requiresthatstructures,systems,andcomponentsimportanttosafetybedesigned,fabricated,erected,andtestedtoqualitystandardscommensuratewiththeimportanceofthesafetyfunctiontobeperformed.AppendixBto10CFRPart50,QualityAssuranceCriteriaforNuclearPowerPlantsandFuelReprocessingPlants,requiresthatmeasuresbeestablishedtoassurematerialscontrolandcontrolofspecialprocessessuchaswelding,andthatpropertestingbeperformed.Thisguidedescribesanacceptablemethodofimplementingtheserequirementswithregardtothecontrolofweldpropertieswhenfabricatingelectroslagweldsfornuclearcomponentsmadeofferriticorausteniticmaterials.Thisguideappliestolightwaterreactors.TheAdvisoryCommitteeonReactorSafeguardshasbeenconsultedconcerningthisguideandhasconcurredintheregulatoryposition.B.DISCUSSIONTheAmericanSocietyofMechanicalEngineers(ASME)BoilerandPressureVesselCode,SectionIII,NuclearPowerPlantComponents,'specifiescertainrequirementsassociatedwithmanufacturingClass1and2components.AlthoughnotpresentlywithinthescopeofSectionIII,weldsforcoresupportstructuresshould,asaminimum,meettherequirementsspecifiedforClass1components.ProcedureQualificationsSection1112requiresadherencetoASMEBoilerandPressureVesselCodeSectionIX,Welding1CopiesmaybeobtainedfromAmericanSocietyofMechanicalEngineers,UnitedEngineeringCenter,345East47thStreet,NewYork,NewYork1001.7.2ASMEB&PVC,SectionIIIandSummer1972AddendatoSectionIII.Qualifications,3whichincludestherequirementsfortheprocedurequalificationforwelds.ReviewoftherequirementsoftheprocedurequalificationstatedinSectionIXindicatesthatsupplementaryre4uirementsaredesirabletoprovideassuranceofadequateweldmetalpropertieswhentheelectroslagweldingprocessisused.Theassuranceofsatisfactoryelectroslagweldsforlow-alloysteelandstainlesssteelcanbeincreasedbymaintainingaweldmetalsolidification(dendritic)patternwithastrongintergranularbondinthecenteroftheweld.Anumberofelectroslagweldingprocessvariables,suchasslagpooldepth,electrodefeedrateandoscillation,current,voltage,andslagconductivity,havebeenshowntoinfluencetheweldmetalsolidificationpattern.Ifthecombinationofprocessvariablesresultsinadeeppoolofmoltenweldmetal,thecrystalline(dendritic)growthdirectionfromthepoolsideswilljoinatanobtuseangleinthecenteroftheweldandcracksmaydevelopbecauseoftheweakercenterlinebondbetweendendrites.SectionI-IinFigureAofthisguideillustratesthedendriticgrowthpattern.Acombinationofprocessvariablesresultinginashallowpoolofmoltenweldmetalwillpromoteadendriticgrowthpatternwithanacutejoiningangleandwillresultinastrongcenterlinebond.Acceptableweldsshouldshowadendriticfreezingpatternwithajoiningangleoflessthan90degreesintheweldcenter.Testsshouldbemadetoassurethattheacceptableweldmetalsolidificationpatternspecifiedaboveisobtainedandthatunacceptablepatternswillnotresult.Theuseofamacro-etchexaminationisasatisfactorytechniquetodeterminetheweldsolidificationpattern,anditshouldbeincludedintheprocedurequalification.SectionIII,asmodifiedbytheSummer1972Addenda,requiresaspartoftheprocedurequalificationforlow-alloysteelweldsthatdropweighttestsbemade3ASMEB&PVC,SectionIXandCodeCase1355-3.USAECREGULATORYGUIDESCopiesofpublishedguidesmaybeobtainedbyrequestindicatingthedivisionsdesiredtotheUS.AtomicEnergyCommission,Washington,D.C.20545,RegulatoryGuidesareissuedtodescribeandmakeavailabletothepublicAttention:DirectorofRegulatoryStandards.CommentsandsuggestionsformethodsacceptabletotheAECRegulatorystaffofimplementingspecificpartsofimprovementsintheseguidesareencouragedandshouldbesenttotheSecretarytheCommission'sregulations,todelineatetechniquesusedbythestaffinoftheCommission,U.S.AtomicEnergyCommission.Washington.D.C.20545,evaluatingspecificproblemsorpostulatedaccidents,ortoprovideguidancetoAttention:Chief,PublicProceedingsStaff.applicants.RegulatoryGuidesarenotsubstitutesforregulationsandcompliancewiththemisnotrequired.MethodsandsolutionsdifferentfromthosesetoutinTheguidesareissuedinthefollowingtenbroaddivisions:theguideswillbeacceptableiftheyprovideabasisforthefindingsrequisitetotheissuanceorcontinuanceofapermitorlicensebytheCommission.1.PowerReactors6.Products2.ResearchandTestReactors7.Transportation3.FuelsandMaterialsFacilities8.OccupationalHealthPublishedguideswillberevisedperiodically,asappropriate,toaccommodate4.EnvironmentalandSiting9.AntitrustReviewcommentsandtoreflectnewinformationorexperience.5.MaterialsandPlantProtection10.Generaltodeterminethereferencetemperature(RTNDT)forbasemetal,theheat-affectedzone(HAZ),andtheweldmetalforClassIvessels.ForClass2vessels,SectionIIIstatesthattheneedforimpact-testingshouldbedeterminedbytheownerandincludedinthedesignspecifications.Experiencehasshownthatthereferencetemperatureforthequenchedandtempered(Q&T)low-alloysteelelectroslagweldmetalisgenerallyhigherthanfortheadjacentbasemetal,andtheweldme