1、BRITISH STANDARD BS EN ISO 17641-1:2004 Destructive tests on welds in metallic materials Hot cracking tests for weldments Arc welding processes Part 1: General The European Standard EN ISO 17641-1:2004 has the status of a British Standard ICS 25.160.40 BS EN ISO 17641-1:2004 This British Standard wa
2、s published under the authority of the Standards Policy and Strategy Committee on 11 August 2004 BSI 11 August 2004 ISBN 0 580 44252 7 National foreword This British Standard is the official English language version of EN ISO 17641-1:2004. It is identical with ISO 17641-1:2004. The UK participation
3、in its preparation was entrusted to Technical Committee WEE/2, Welding tests, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publicati
4、ons referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessa
5、ry provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpr
6、etation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, pages 2 to 8, an inside back cover and a
7、back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO176411 August2004 ICS25.160.40 Englishversion Destructivetestsonweldsinmetallicma
8、terialsHotcracking testsforweldmentsArcweldingprocessesPart1:General (ISO176411:2004) Essaisdestructifsdessouduressurmatriauxmtalliques Essaisdefissurationchauddesassemblagessouds ProcdsdesoudagelarcPartie1:Gnralits(ISO 176411:2004) ZerstrendePrfungvonSchweiverbindungenan metallischenWerkstoffenHeir
9、issprfungenfr SchweiungenLichtbogenschweiprozesseTeil1: Allgemeines(ISO176411:2004) ThisEuropeanStandardwasapprovedbyCENon9February2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalte
10、ration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmember
11、intoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway
12、Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnatio
13、nalMembers. Ref.No.ENISO176411:2004:EENISO176411:2004(E) 2 Contents page Foreword. 3 1 Scope . 4 2 Normativereferences . 4 3 Termsanddefinitions. 4 4 Symbols,designationsandunits. . 5 5 Fundamentalsofhotcracking . 5 6 Typesoftest. . 6 7 Descriptionoftests 6 8 Summaryofapplications . 7ENISO176411:200
14、4(E) 3 Foreword Thisdocument(ENISO176411:2004)hasbeenpreparedbyTechnicalCommitteeCEN/TC121“Welding”, thesecretariatofwhichisheldbyDIN,incollaborationwithTechnicalCommitteeISO/TC44“Weldingand alliedprocesses”. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidentic
15、al textorbyendorsement,atthelatestbyFebruary 2005,andconflict ingnationalst andardsshallbewithdrawn atthelatestbyFebruary 2005 . ENISO17641consistsofthefollowingparts,underthegeneraltitle Destructivetestsonweldsinmetallic materialsHotcrackingtestsforweldmentsArcweldingprocesses: Part1:General Part2:
16、Selfrestrainttests Part3:Externallyloadedtests 1 AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,Cyprus,CzechRepublic, Denmark,Estonia,Finland,France,Germany,Greece,Hungary,Iceland,Ireland,I
17、taly,Latvia,Lithuania, Luxembourg,Malta,Netherlands,Norway,Poland,Portugal,Slovakia,Slovenia,Spain,Sweden,Switzerland andUnitedKingdom. 1 Part3willbepublishedasaTechnicalReportwiththesamegeneraltitle.ENISO176411:2004(E) 4 1Scope Thisstandardgivesanintroductiontothefundamentalsofhotcrackinginweldmeta
18、lsandparentalloys,and brieflydescribesthetestsavailableforarcweldingprocesses. Part2:Selfrestrainttestsspecifiesthetestswhichshouldbeusedtoassessthesusceptibilitytohot crackingofweldmetals.Thestrainstocausecrackingareprovidedbytherestraintoftheweldment. Part3:Externallyloadedtestsdescribesthetestswh
19、ichcanbeusedtoassessthesusceptibilitytohot crackingofparentalloysandweldmetals.Thestrainstocausecrackingareprovidedbyexternalloading onthetestspecimen. NOTE Thetestsinpart3requiretheuseofnonstandardisedproprietaryequipmentanddifferentlaboratoriesuse variousprocedures,testconditionsandspecimensizes,t
20、hereforereproducibilitywithinagivenlaboratoryisusuallygood butdifferencesbetweenlaboratoriesaresometimesfound. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications. Thesenormativereferencesarecitedattheappropriateplacesinthetext,andthepublic
21、ationsarelisted hereafter.Fordatedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplyto thisEuropeanStandardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthe latesteditionofthepublicationreferredtoapplies(includingamendments). ENISO176412:2004, Destructivete
22、stsonweldsinmetallicmaterialsHotcrackingtestsforweldments ArcweldingprocessesPart2:Selfrestrainttests(ISO176412:2004). prCENISO/TR176413:2003,DestructivetestsonweldsinmetallicmaterialsHotcrackingtestsfor weldmentsArcweldingprocessesPart3:Externallyloadedtests(ISO/DTR176413:2003). 3 Termsanddefinitio
23、ns ForthepurposesofthisEuropeanStandard,thefollowingtermsanddefinitionsapply. 3.1 hotcracks materialseparationsoccurringathightemperaturesalongthegrainboundaries(dendriteboundaries)when thelevelofstrainandthestrainrateexceedacertainlevel NOTE SmallcracksvisibleonlyatmagnificationsgreaterthanX50,areo
24、ftendescribedasmicrocracks. 3.1.1 solidificationcracks hotcracksformedduringsolidificationfromtheliquidphaseofweldmetals NOTE Theyusuallyextenduptothesurfaceoftheweldmetal,butsometimescanbesubsurface. 3.1.2 liquationcracks hotcracksformedbyliquationoftheheataffectedzone(HAZ)oftheparentmaterialorinmu
25、ltipasswelds whereweldmetalisreheatedbysubsequentweldbeadsENISO176411:2004(E) 5 3.1.3 ductilitydipcracks hotcracksformedduringweldingbyareductioninhotductility.Aswithliquationcrackstheycanoccurinthe HAZoftheparentmaterialorinmultipasswelds 3.2 selfrestrainttests testswherespecimenloadingisproducedby
26、strainsdevelopedduringweldingofarestrainedweldment 3.3 externallyloadedtests testswherestrainsaredevelopedinthespecimenbytheapplicationofexternalloadsinspecifictest equipment 4 Symbols,designationsandunits ForthepurposesofthisEuropeanStandard,thesymbolsandunitsgiveninTable1apply. Table1Symbols,desig
27、nationsandunits Symbol Designation Unit MSI(TT) Microcrackssensitivityindicator(tensiletest) a mm/mm 2 MSI(LBT) Microcracksensitivityindicator(longitudinalbendtest) b mm/mm 2 Ltot Totallengthofalldetectedhotcracks mm Vcrit Criticalstraintoformthefirsthotcrack mm/s BTR Brittletemperaturerange,i.e.dif
28、ferencebetweenNSTandDTR(seeprCEN ISO/TR176413:2003,Figure2) K a MSI= L MF lL o x d x p b MSI= L MF lbx l o 5 Fundamentalsofhotcracking HotcracksareproducedintheweldmetalandintheHAZofparentmaterialswhenthestrainsdeveloped duringcoolingofaweldedjoint,orimposedexternally,exceedtheductilityofaparticular
29、partofthejoint. Theyrangeinsizefromverysmallliquationcracks(1mminlength)inHAZsormultipassweldsuptolarge solidificationcracks,whichmayextendalongthecompletelengthoftheweldedjoints. NOTE1 Thesecracksshouldnotbeconfusedwithcoldcracks,whichalwaysoccurattemperaturesbelow200C. Hotcracksarenotconfinedtoany
30、particularalloysystemandcanoccurinsteels,stainlesssteels,nickel basealloys,copperandaluminiumbasedalloys.Thereasonsfortheincidenceofhotcracksaremanyand complex,butingeneraltermstheyoccurwhenlocalisedductilityisinsufficienttosupportimposedstrains.The lackofductilitycandependuponmicrostructuralfeature
31、sandorientation(relativetothestrains)andinsome casesuponthepresenceofbrittleimpuritiesandlowmeltingpoint(orliquated)films.Inthisrespectsome alloysystemsarehighlysensitivetothepresenceofimpurityelementssuchasSulphur,Phosphorus,Lead, etc.Itisgenerallyrecognisedthatfullyausteniticsinglephasemicrostruct
32、ures,particularlyweldmetals,are susceptibletohotcracking,ofoneformoranother.Impuritylevelsinfluencetheincidenceofcrackinginsuch structures. NOTE2 Precisemechanismsfortheoccurrenceofhotcrackinghavenotyetbeenfullyestablished.ENISO176411:2004(E) 6 6 Typesoftest 6.1Selfrestrainttests Thesetestsdependupo
33、ntherestraintoftheweldmenttoprovidesufficientstraintoinducecracking.The testsinclude: a) Thosetestsconsistingofahighlyrestrainedweldmentwherethetestweldisexamineddirectlyforthe presenceofcracking; b) Testsconsistingofafullthicknessbuttweldwherethetestspecimenistakenfromtheweldmetalinthe buttweldands
34、ubjectedtoadditionalstrainingtorevealpreexistinghotcracking(particularlymicro fissures)andfacilitatetheirdetectionandmeasurement.Thepostweldstrainingisappliedeitherby tensionorbybending.Itisnotdesignedtoinduceanynewcracking. Theselfrestrainttestsareonlysuitablefortheassessmentofhotcrackinginweldmeta
35、ls. 6.2Externallyloadedtests Thesetestsdependuponexternalloadingonthespecimen,eitherduringtheweldingprocessoronawelded specimenwhichissimultaneouslyheatedandloaded.Thetestsinclude: a) testswhereloadingisimposedastheweldisdeposited; b) testswhereaweldisreheatedandloadedsimultaneouslytoallowanassessme
36、ntofsusceptibilitytobe determined. Theseexternallyloadedtestsaresuitablefortheassessmentofhotcrackinginweldmetals,parentmaterials andheataffectedzones. 7 Descriptionoftests 7.1Selfrestrainttests 7.1.1General DetailsofthetestproceduresaregiveninENISO176412. 7.1.2 Tjointweldcrackingtest Thetestprocedu
37、reisdesignedtoassessthesolidificationcrackingsusceptibilityofweldmetalinasingle passrestrainedfilletweld.Threetypesoftestareavailable,withincreasingrestraintbeingprovidedby increasingthethicknessand/orstiffnessoftheplatesusedinthetestassembly.Theassessmentis essentiallyqualitativesincenodirectmeasur
38、ementofstrainsisavailable.Assessmentisbaseduponthe lengthandpositionofcracking(ifany)inthetestweld. 7.1.3 Weldmetaltensiletest Thistestisdesignedtoassessthesusceptibilitytoliquationandductilitydipcrackingofweldmetaltakenfrom abuttweld.Applyingaloadtoruptureacylindricalallweldmetalspecimentakenfromab
39、uttweldopens cracksinitiatedduringtheweldingoperation.Theregionsadjacenttothefractureareexaminedandany crackingcanbedetectedandmeasured. NOTE SeeENISO176412:2004,Figures2and3.ENISO176411:2004(E) 7 7.1.4 Longitudinalbendtest Thistestisdesignedtoassessthesensitivitytosolidification,liquationandductili
40、tydipcrackinginallweld metalbuttwelds.Bendingatestspecimentakenlongitudinallyfromabuttweldopensupcracksinitiated duringtheweldingofthebuttweld.Anycrackingcanbedetectedandmeasured. NOTE SeeENISO176412:2004,Figures4and5. 7.2Externallyloadedtests 7.2.1General DetailsofthetestproceduresaregiveninprCENIS
41、O/TR176413. 7.2.2 Hottensiletest Hotcrackingsusceptibilityisdeterminedbycarryingoutatensiletestwhileatthesametimeheatingthe specimentosimulateathermalcycle. Adifferentprocedureanddifferentspecimendimensionsareusedtoassesssusceptibilitytosolidification crackingfromthoseusedtoassesssusceptibilitytoliq
42、uationcracking: a) Tosimulatesolidificationcrackingthespecimenisheatedtothemeltingtemperatureandthejawsofthe equipmentareheldfixedsothatshrinkagestrainsinducecracking; b) Tosimulateliquationcrackingspecimensareheatedtotemperaturesjustbelowthesolidusand susceptibilityisbasedonthetestingofanumberofspe
43、cimenstoproduceahotductilitycurve. 7.2.3 TheVarestraintandTransvarestrainttests TheVarestraintandTransvarestrainttestsareusedtoprovideameasureofthehotcrackingsusceptibilityby weldingandloadingsimultaneously.IntheVarestrainttesttheloadisappliedinthelongitudinaldirectionof theweldbeadundertestandiscapableofassessingsolidification,liquationandductilitydipcracking.Inthe Transvarestrainttesttheloadisappli
