JB 4708-2000 英文版 钢制压力容器焊接工艺评定

JB4708—2000JB/T4709—2000JB4744—2000钢制压力容器焊接工艺评定钢制压力容器焊接规程钢制压力容器产品焊接试板的力学性能检验MechanicalpropertytestsofproductweldedtestIssuance：15-08-2000Implementation：01-10-2000TheStateBureauofPetrolNoticefortheIssuanceofFourIndNo.：SMIB[2000]401ThisistonotifythatinaccordthefourindustrialstanVesselsaretobereleasedwiththeindivisureVesselfTheStatePetroleum&—2—Preface 4 52.Quotedstandards 53.Terminologies 64.Generalprinciples 75.Weldingprocedu 86.Weldingprocedurequa 23AppendixA(appendixforstandard)Weldingproced 36AppendixB(appendixforprompts)Weldingprocedureinstructirecommendedpatternsofweldingprocedurequalificationrecord JB/T4709-2000Weldingspe4.Weldingprocedurequa5.PreparationbdAppendixB(appendixforprompts)RecommendedformofweldingprocedureinstructionJB4744-2000Mechanicalpropertytestsofproductweldedtestcoupon4.Themanufacturingrequirementsofproductweldedtestcoupons5.Testsamplepreparationofproductweldedtestcoupo—4—WeldingprocedurequalificationforsteelpressurevesselsThisstandardstipulatesweldingqualifiedindexesforsteelpressurevesThestandardissuitableforweldinelectricalarcwelding,submergwelding,electroslagwelding,corrosion-resistingbeadwelding,etc.forsteelThearticlesincludedinthefollowingstandardsbecomearticquotation.Whenbeingpublished,allversionsofthestandardsarevalid.Sinceallstandardswillberevised,everyusershallseekthepossibilityofadoptingthelametalstensiletestingmethmetalsimpacttestingmethodofxiabinotchmetalsbendingtestingmethodseamlesssteelpipeforlowandmiddlepresscold-rolledstainlesssteetheNo.1modificationlist)seamlesssteelpipeforhigh-presseamlesssteelpipeformodificationlist)seamlessstainlesssteelpipeforboiler’seamlessstainlesssteelpipeftheforgedpiecesofcarbonsttheforgedpiecesoflowalloysteelforlow-temperaturepressurethestainlesssteelforgedpiecesforpressurethenon-destructivedetectionforpressurevesseThestandardadoptsthefollowingofweldingpiece’sdraftedweldingprocedure.Theweldingproceduredocumentsdrawnupforverificationexperiments,anevaluationandtobeusedtoguidethepr3.3ProcedurequalificatiTherecordreportingwhichmadearecordofaresultoftheverdesignatedformsandevaluatedthecorrectnessofthedraftedweldingprocedure.Thejointpointwheretwoormorethantwopartswillbeweldedorhtogether,wheninspectibetakenintoaccount.Thepressurevesselsorotherpartsjoinedbywelding,theweldmentincludingbasemetalsandweldedjoints.Theweldmentforweldingprocedurequalificationtestmanufacturedaccordingtothepredeterminedweldingprocedure.Thetestpieceincludesbasemetalandweldedjoints.eheatingprocessthatcanchangethetissuesandpropertiesofweldedjointsr3.8LowertransformationteThephasechangetemperatureduringtheheatingprocesswherebeginstoforminto3.9UppertransformationteThephasechangetemperatureduringtheheatingprocesswherefinishesausteniteThebendbecauseoftheaxisoftheweldingseamisperpendiculofthetestpiece.ThebendbecauseoftheaxisoftheweldingseamisparalleltothelongitudinalaxisoftheThebendbecauseofthetensilesurfaceofthetestpieceisthefrontsideoftheweweldingseamwidthsinbothsidesareequal,thenthefaceThebendbecauseofthetensilesurfaceofthetestpieceisthereversesideoftThebendbecauseofthetensilesurfaceofthetestpieceisthetransversesectionofthe4.1Theweldingprocedurequalificationshouldbebasedonreliablesteelwpropertiesandfinishedbeforeweldingproduct4.2Thegeneralprocessofweldingprocedurequalificationis:dprocedureinstruction,weldingtestpiecesandmapiecesandsamples,measuringifweldedjointshavetherequiredutilityproperties,submittingweldingprocedurequalificationrecordandevainstruction.Theweldingprocedurequalificationverifiesthecorrectnessofweldingproceduredrawnupbytheweldingunitandjudgesitscapability.4.3FortheT-typejointsandanglejoitheirinteriordefectscsuretheweldingthroughout,thrweldingprocedurequalificationandtheweldingshallbeallowedo4.4Theequipmentanormaloperatingcondition,steelsandweldingmaterial5.Weldingprocedurequaprocedurequalification.Thequalifiedbuttweldingprocedureissuitableforfillet-weldingseam.Whenevaluatingtheweldingprocedureofno-pream,thefilletweldingtestpiecescanbda)Theplatebuttweldingtestpieceb)Thepipebuttwea)Theplatefilletweldingtestpieceb)TheplateandpipefilletweldingFigure1Thetestpiecesshapes5.1.1Thequalifiedweldingprocedureoftheplatebuttweldingtestpiecesisapplicabletothepipebuttweldingseam,andviceversa.5.1.2Thequalifiedweldingprocedureoftheplateandpipefillapplicabletotheplatefillet-weldingseam,andvice5.2Theweldingprocedureelementsar5.2.1Theimportantfactorrefersweldedjoints′tensilestrengthandbendstrength..2.2Theaddittweldedjoints’impacttoughness.Iftheimpacttesti5.2.3Theminorfactorsrefertotheweldingprocedurefactorsthathavenomarkedinfluenceonthestipulatedmechanicalprop5.3Qualificationr5.3.1.1Re-qualificationisindispensableifchangingtheweldingmethod.5.3.1.2theimportant,additionalandminorfactforvariouskindsofweldingmethodsseetb)Whenaddingorchanginganyadditionalfactor,toughnesshavetobetestedaccordingtotheaddedorchangedadditioc)Whenchangingminorfactors,re-qualificationoftheweldingprocedurequalificationisunnecessary,buttheweldingprocedureinstructionshouldbrweldingprocedurewhenitisweldedbyabequalifiedcomprehensivelybyadoptingthetwoormoreweldingmethods,proceduresandweldingpieces.Whenbeingappliedtotheweldmentaftercomprehensivequalificationqualificatmoreweldingmethods,weldingprocedurecanadditionalfactorsshouldberemainedunchangreachweldingmethodorweldingproceduredeterminestheeffectiveranrweldment′thickness.chemicalcomposition,mechanicalpropertiesandweldingproperties(seetable2).a)WhentheimportantaprocedureofonegradebasemetaII-1.numberissuitablefortheweldedjointbasemetalswithlowergroupnumber.d)Apartfromthecircumferencesthatisregulatedimetalsgroupnumber,therehavetohaveare-qu5.3.2.2ClassificationqualificationForweldedjointsmadefrombasemetalswithdifferentclassification,emetalhasbeenqualified,re-qualificationfortheweldedjointsisnecessary.ButthequalificationoftheIIclassification(orVI-gradeissuitablefortheweldedjointsfromthesameclassification(ortmetalandtheIclassificationbasemetal.5.3.2.3Qualificationregulationsofthesteelgradesnotincludingintable2classifiedintotheircorrespondingclassificationsandgroupsorintonewclassifandgroupsaccordingtotheirchemicalcomposition,mechanicalpropertiesandweldinggradesthatarenotincludedinNatib)Fortheforeignsteels,theweldingprocedurequalificationshouldweldingpropertieshavebeenknownapropertiesareequivalenttothatofonesteelgradeintable2,andtheweldingproceduqualificationforthatsteelcodequalificationforthisforeignsteelcanbeexempclassificationandgroupofthatsteelgradeintheunit′stechnologydocuments.5.3.3Post-weldinghe5.3.3.1Classificationsofthepost-weldingheattreatment5.3.3.1.1ThebasemetalswithclassificationNo.VIIb）Carryingoutthesolidsolutiontreatmentorstabilizationheattreatm5.3.3.1.2ThebasemetalsexceptclassificationNoVIIareb)Carryingoutpost-weldingheattrtransformationtemperaturc)Carryingoutthepostweldingheattreatmentwhentemperatureishigherthantheuppertransformationtemperature(forexample:normalizing);d)Carryingoutthepostuppertransformationtemperature,thenintemperaturetransformationtemperature,(e.g.temperingafternormalizingorquenching);e)CarryingoutthepostweldingheattreatmentbetweentheupperatransformationtemperaturWeldingprocedurere-qualificationisnecessaryifchangingthekindofpost-Whentheimpacttestisspecified,Theweldingprocedurequalificationisneededifchangingtherangeoftemperatureandthetimeofthepost-weldingheattreatment.Butthegasweldingistheexception.Thepost-weldingheattregenerallysameasthatoftheweldedpiecesinthemanufacture,theheatingtemperattestpiecesshouldnotviolatetheregulationsodocuments.Whencarryingoutthepost-weldingheattreatmentwiththetemperaturebelowthelowertransformationtemperature,t80%oftheweldingpiecesamountedholdingtimeduringitsmanufacturingprocess.5.3.4TestpiecesthicknessaTheeffectiveextentofweldingpiecesthicknessforwhichthequalifiedweldingprocedureofbuttweldingtestpiecesissuitable:followingtheregulationsoftable3and4ifthebasemetalsofthetestpiecesareinfollowtheregulationoftable5and65.3.4.1Fortheelectric-arcweldingofwelding-tungsten-arcweldingandgasmetpieces,inthecaseofT≥8mm,theminimumoftheeffectiveextentoftheweldingbasemetalsthicknessaftertestpieceshadbeenassessedasqualificationshoulitwouldbetreatedaccordingtotheoriginalregulationsifthetestpieceshavebeenprocessedbypost-weldingheattreatmentintemperatureabovettemperatureortheaustenitebaseme5.3.4.2Iftheweldingpiecesarewithinthecircumferenceoftable7,themaximumoftheeffectiveextentofweldingpiecesbasemetalsthicknessshoultable7aftertestpieceshadbeenassessedasqualificatioTable3TheregulationonthetestpiecesbaseweldingpiecesbasemetalsthicknessmmThetestpiecesbasethicknessTTheeffectiveextentsuitableforweldingpiecesbasemetalsthT2TTable4TheregulationsonthetestpiecesweldiandweldingpiecesweldingseammetalsthicknessThetestpiecesweldmetalsthicknesstTheeffectiveextentsuitableforweldingpiecesweldingsNolimitation2tNolimitationNolimitationNote:trepresentsthicknessoftheweldedwelding-seammetalbythesameweldingmethod(orweldingprocedure).Table5Theregulationonthetestpiecesthicknessanoutthetestpiecesmechanicalpropertiestestandtransversebendingtebasemetal′sthicknessTweldingpiecesbasemetalsthicknessTheeffectiveextentsuipiecesweldingseammetalthicknessT2TNolimitation2t2TNolimitation2t52TNolimitation2t5Nolimitation5Nolimitation*Limitedtomulti-runweldingofwelding-rodelectricarcwelding,submerged-arcwelding,tungsten-arcweldingandgasmetal-arcweldingTable6Theregulationonthetestpiecesthicknessandoutthetestpiecesmechanicalpropertiestestandlongitudinalbendingbasemetal′sTheeffectiveextentsuipiecesbasemetalsthicknessTheeffectiveextentsuipiecesweldingseammetalthicknessthicknessTT2TNolimitation2t2TNolimitation2t52TNolimitation2tTable7thetestpiecesthicknessandtheregulathicknessinspecialconditionNo.Theweldingpiecescoweldingpiecesbasemetalsthickness1welding-rod *thequalificationresultsofothersweldingseamscontinualfilling.tungsten-arcweldingandgas2Thepartbuttweldingpi*Nolimitation3*Nolimitation4weldingtestpiecesshouldassessedbytheequal-thicknessbuttweldingtestpiecesbasemetalwhose*thicknessofthethickerNolimitation*thicknessofthethickerNolimitation*Accordingtothetest5.3.4.3Ifthetestpiecesconformtotheweldingconditionsintable8,themaximthicknesssuitableforweldingpiecesaftertestpieceshavebeenassesTable8.Regulationsonthetthicknessinspecialweldingcondition—20—NoThetestpiecesweldingconThemaximumthicknesssuita1Exceptgaswelding,thetestpiecesbeingprocessedbypostweldingheattreatmentovertheuppertransformationtemperature.*2welding,ifthethicknessofanyoneofitswelding*3T*4*5Whenthetestpiecesthicknessisthickerthan150mm,andadoptingmulti-runweldingofwelding-rodelectric-welding,gastungsten-arcweldingandgasmetal-arcwelding(excepttheshort-circ6Whenthetestpiecesthicknessisthinnerthan*7metal-arcweldingwithshort-circuitedtransition**Accordingtothetesttables4,5,6andartiqualifiedweldingprocedureforbuttweldingtpieces;Thereisnolimiqualifiedweldingprocedureforfilletweldingtestpiecesisappliedtothenon-pressurefilletweldingpieces.5.3.4.5Afterfinishingthecompoundqualification,theeffectiveextentpiecesbasemetal’sthicknessshouldbedeterminedbysingleweldingmethods(orweprocedure)qualification.6.Weldingprocedurequalificationr6.1Re-qualificationisindispensableifchangingthebeadweldingmethod.6.2IfthethicknessofthetestpiecesbaselayerTislessthan25mm,thequalifiedweldingprocedureissuitableforweldingpieceswhosebaselayer’sthicknessTisnolessthanTorequaltoT,Ifthetestpiecesthicknes—21—ThebeadweldingcondThebeadweldingcond6.3Theweldingconditionsforre-qualificationofthecorrosion-resistingbeadweldingseeTable9.Weldingconditionsforre-qualificationofthecorrosion-Thebeadweldinglayethanthequalifiedminimumthickne ○○○○○Changingtheclassificationo○○○○○○Thethicknessofthebaselayerstetheregulationof6.2○○○○○○consideringthelatertwodigitsofits ○ Changingweldingrod’sdiameterwheourthefirstlayerbeadwe ○ Addingorcancelingadditionalfillerme ○○ ○Changingthesteelgradeoftheweldingwire(or ○○○○Changingtheweldingflux’smixingproportionofthemixingweldingflux ○ ○Changingthesolidweldingwiretotheshielcoredweldingwire,orvi ○○ Thebeadweldingcond—22—positionExceptthequalificatithequalifiedweldingpositi ○ ○○ Thepre-heatingtemperatureis50℃lowerththequalifiedvalueorisolayertemperatureofthequalificationrecord ○○○○○treatmentofpost-weldingChangingtheclassificationoftheheattreatmentofpostwelding,orthetotalincreasedtimethepostweldingheattreatmentexceedsthequalifiedtimeby25%.—○○○○○Changingtheclassificationofshieldedchangingthemixingproportionofthemixingshieldedgas,canceling———○○—Changingcurrent’sclassif ○○○○○Theincreasedlinearpowerorthevolumeofweldedmetalonperunithasexceededtheassessedqualificationvalueby ○○○○○Changingthemulti-layerbeadweldingtosingle–layerbeadwelding,orvice-versa. ○○○○○Cancelingthemagneticfieldcontrolof——○——○Changingthequantityoftheelectr ○○ ○Addingorcancelingelectr ○○○○Note:1.Thesymbol“○”meansthat7.1Thetestpiecepr7.1.1Basemetals,weldingmaterial,groovesandtestpiece’sweldconformancewiththerequirementsoftheweldingprocedureinstruction.7.1.2Quantityandsizesofthepreparation.7.1.3Thebuttweldingtestpiecessizes:thetestpiecesthicknessshouldconsiderabtheeffectiveextentofweldingpiecesthicknessintoaccount.—23—7.1.4Thefilletwelding7.1.4.1TheplatTheabdominalplate’sthicknessT2T12.Thetestsample’ssizesformeseam,moltenzoneandheFigure2.Platefilletweldingtestsamplesandtestp7.1.4.2thepipefilletweldingtestpiececanadoptpipe-plateorpipe-pipetest—24—1.TisthicknessofpipewallbenolessthanT3.Themaximumweldingfootequpipewallthickness4.Thedottedlineinfiga)Thepipe–platefilletwelding1.Tisthicknessofinnerpipewall2.ThethicknessofouterpipewallshouldbenolessthanT3.Themaximumweldingfootequinnerpipewallthi4.Thedottedlineinfigb)Thepipe–pipefilletweldingtestpiFigure3Pipefilletweldingtestp7.1.5Thecorrosion-resistingbeadweldThetestpieceshouldbenosmallerthan150mm×150mm,t7.2Thebuttweldingtestpieceandt7.2.1Thetestpiecesinspectionitems:thevisualinspecmechanicalpropertyandthebendpropertyinspectioAfterthevisualinspectiona7.2.2Theinspectionitemsofthemechanicalpropetensiletest,impacttest(whenspecified)andbendingtes.2.2.1Thetestingitemsandsamplidpropertyshouldbeinconformancetoregulati7.2.2.2Whenadoptingthea)Thetensilesurfaceofthetensiletestpieceandthebendingtestpieceshouldincludetheweldingseammetalofeachweldingmethod(orweldingprocedure);heat-affectedzoneofeachweldingmethod(orweldingprocedure).—25—ofthetestpiecebasemetalTThetestingitemsandsbendbendbend222 222—33222332——4331)Allcrosssectiontestpieceofonepipejointcanreplacethetwoplate-shapetestsa2)Whenthebendpropertiesbetweenthebasemetalinthetwosidesoftheweldingseamortheweldingseammetalandbasemetalaregreatlydifferent,thelongitudinalbendingtestcanreplacethetrbendingtest.Onlythetwofacebendandtworootbendtestsamplesareneededfor3)Usingfourtransversesidebendtestsamplestoreplacetwoface4)Whenthesteelgradeofthebasemetalsintwosidesoftheweldingseamaredisamplesshouldbemadefromeachheat-affected5)Ifthelittlesizetestsamplesof5mm×10mm×55mmcouldnotbemade,theimpacttestisabolis7.2.2.3Thesamplingrequirementsonthemechanicalpropertiesandthebendingpropertaccordancewiththeregulationsofc)andd).b)Thetestsample’scoldlevelingarc)Thesamplingpositionsonplatebuttweldingtestpieced)Thesamplingpositionsonpipebuttwelding—26—Figure4Testsamplepositionontheplatebu—27—a)Thetestsample’spositionwhenthetensiletesb)Notspecifyingimpacttest1-thetensiletestsample;2-face4-sidebendtestsample;5-iTheclockmarksof③⑥⑨(12)arethepositioningmarksforhorizFigure5.Testsamplepositionofthepipebuttweldingtestpiece7.2.2.4Thetens7.2.2.4.1Samplingandmachiningrea)Theweldingsurplusheightothetestsamplesshouldbinlinewiththebasemetal.ThethicknessofthetestsamplesshouldbeequivalentorapproximatetothethicknessTofthetestpiece’sbasemetal.c)Whenthetensiletestarenotallowedbecauseofthetensiletestingmac—28—thetestpiecesshouldbeevenlysampledlayerbylayeralongtestingthicknessofthetensiletestingmachine.Thetestsoftwooafterevendivisionmayreplacethetestingofafull-thicknesstestsample.a)Thetestsampleoftsuitablefortheplatebuttweldingtestpieceofanythickness.b)ThetestsampleIofthecompactpipejsuitableforthepipebuttw76mmwithanywalltS——Thetestsample’hk——Theweldingseamsmaximumwidh——Thelengthofholder,determinedaccordingtothetestmachineFigure6TensiletestsampleofthecompactplatejointwithshoulderplateshapeNote:Toobtaintheparallelsurfaceof20mmwidthshowedinfigure,volumealongthewallthicknessdirectionshouldbereducedaspossiFigure7TensiletestsampleshapeⅠofthecompactpipejointwithshoulderplateshape—29—L——Thetensileparallelsidelength,equalstoorlargerthanhk+2S,mm.Figure8TensiletestsampleshapeIIofthecompactpipejoind)ThefullcrosssectiontestsampbuttweldingtestpiecewhoseexteriordiameterisnolargerthanFigure9FullcrosssectiontestsampleofthepipejointThetensiletestshouldbeconformedtothetensilestrengthoftheweldedjoint.7.2.2.4.4Qualificationa)Thetensilestrengthofeachtestsampleshouldspecifiedstandardvalb)Thetensilestrengthofeachtestsampllowerlimitofthespecifiedstandardvalueoftwosteelgradeswhenthetestsamples’basemetalaretwostethicknessdirectionshouldbeinconhighalloysteel）lowerlimitof7.2.2.5Thebend7.2.2.5.1Thetestsamples’machiningTheweldingsurplusheightofthetestsamsamples’tensilesurfacesoffacebendandrootbendshouldbeinlinewiththeheightandWhenthetestpiece′sthicknessT≤10mm,thetestsample’sthicknessSshouldbeberemovedfromtestsample’spressb）ThetestsampleofthetransversWhenthetestpiece’swidthTis10~38mm,thetestsample’swidthshouldbeequivalenttothethicknessofthetestpiece.Whenthetestpiece’sthicknessTismorethan38mm,itisallowedtoreplacethetestingofafullthicknesssidebendsamplesof20~38mmwidthbyevenlycuttingtestpiecelayertolayer.7.2.2.5.3Thetestintomeasureitsperfectionandplasticityoftheweldedjoint.Thetestpiece′sThediameterofb)Thecenteroftestsample’moreserioussideshouldc)Thebendingangleshouldtakethemeasuringresultsdocuments′specifiedvalueislowerthan20%itsactualmeasuringvalueisδ<20%.There-measurementisadiameterofthebendingcore,atthemomentthediamete(δisthelowerlimitoftensilerate′sspecifiedvalue),thebracketsdistanceequalstothebendingcore’sa)Thefacebendtestsampleforplateandpipb)Therootbendtestsampleforplateandpipetestpc)Thetransverseface1.Thetestsample’sleng0~<50mm,thenB=10mm;dequallyintofourpartsalon1B---testsample’swidth(inthetestpiece′sthic7.2.2.5.4QualificationWhenbeingbenttothespecifiedangle,nocrtheaxisoftheweldingseam,thenotch’saxisshouldbeperpendiculartothesurfaceofa)Theimpacttestsamplingpositionoftheheat-affectedzoneb)Theimpacttestsamplingpositionoftheweldingseamzone2.Whencarryingoutbi—facewelding,t2shouldbemeasuredfThenotch′saxisoftheweldingseamzonetestsampleshouldbepasstheheat-affectedzoneasmoreasposs7.2.2.6.2ThetestsamtheregulationsofGB/T229.7.2.2.6.3QualificationIneachzone,theimpactabsorbingpower’saverageofthreetestsamplecorrespondingregulationsofdrawingsorrelevthan27J,atmostonetestsamplspecifiedvalue,butitcannotbelowerthan70%specifiedva7.3Thefillettestpiecesa7.3.1Inspectionitems:thevisualinspection,themetallographicinspection(macroTherenotbeallowedanycracksbythevisualins7.3.2Themetallographicinspection(macro7.3.2.1.1Theplata)20mmshallbecutoffatthebothendsofthetequallyintofivetestsamplesinthelongitb)Carryingoutmetallographicinpositionoftheweldingseamshouldbeinthweldingseam.twoinspectionsurfacesarenotallowedtobethetwosidefaces7.3.2.2Qualificationa)Theweldingseamsrootshouldbeweldedperheat-affectedzonearenotallowedtohavecracksandub)Thefilletweldingfoot’sdifferen7.4Thecorrosion-resistingbeadweldingtestpieceandtest7.4.1Inspectionitems:permeationinspection,bendingtestandthechemicinspectionmethodsshouldbeinconformancetotherpermeationinspection,everytwotestsamplescweldingseamandperpendiculartotheweldingseoffperpendiculartotheweldingseam,thesamplingpositionseefigure1layer′sheat-affectedzone,beadweldinglayer)equalstoT.7.4.3.2ThetestfTable13TheregulationsonbeadThediameterof7.4.3.3Qualificationcracksordefectsw7.4.4Thechemicalcomp7.4.4.1ThesamplingSamplinginthecrosssectionofthebeadweldinglayer’smicorrosion-resistingbeadweldingtestpi7.4.4.2Thechemicalcompositionanalysismethodshouldbregulationsofthecorrespondingstandardsanddrawings.7.4.4.3Qualificationindexesshouldbeinconformancorrespondingtechnologyd7.4.4.4Thequalifiedminimumthicknessofthebeadweldinglayer(seefdistanceaisthequalifiedminimumthicknessofthebeadweldinglayer.Figure14Thesamplingschematicdrawiofthecorrosion-resistingbeadweldingthentheweldedlinetomachiningsurfacedistancthicknessofthebeadweldinglayer.thedistancecfromtheweldedlinetothqualifiedminimumthicknessofthebeadweldinglayer.adoptingrolling,percussionrolling,percussionandbeadweldinA1.2Theweldingprocedurequalificathecorrespondingregulationsintext