简介：ThemicrostructuralevolutionandVickershardnessmeasurementintheweldingheat-affectedzone(HAZ)ofHD15Ni1MnMoNbCusteelfornuclearpowerstationwereinvestigatedbyGleeble-3180thermalmechanicalsimulator,andthesimulatedHAZcontinuouscoolingtransformationcurves(SH-CCT)weremeasuredsimultaneously.Witht_(8/5)increasingfrom3.75sto15000s,theproductwasobtainedmartensite,bainite,ferriteandpearlite,successively.TheresultofmicrostructureandVickershardnessintheheat-affectedzonewasingoodagreementwiththosemeasuredbySH-CCTdiagramwiththeheatinput16.2kJ/cmasanexampletoweldtheHD15Ni1MnMoNbCusteelpipeusingTIG/SMAW/SAWweldingmethods.

简介：Thispaperstudiedthespotweldingstructureofultra-highstrengthsteel22MnB5.ANSYSsoftwarewasadoptedtosimulateitsstaticstrength;BS5400algorithmwasusedtocalculatethefatiguelife;andthegroupingmethodwasusedtotestthefatigueperformanceoftensileshearspotweldspecimens.Thesimulationresultswereingoodagreementwiththeexperimentalvalues.Basedonthevalidationofthesimulationmethod,influencesofdifferentstructuralparametersonstaticstrengthandfatiguelifewereexploredbyadoptingsinglefactor.Theresultsshowedthatwithintheselectedstructureparameterrange,increaseofthesheetthickness,nuggetdiameter,sheetwidthandoverlappinglengthcanleadtolongerfatiguelife.Besides,thefatiguelifeofspotweldtookonalinearrelationshipwiththeoverlappinglength,aDoseResprelationshipwiththesheetthickness,andasingleexponentialdecayrelationshipwiththesheetwidthandthenuggetdiameter.Moreover,inordertoestimatetheimpactfromvariousparametersonthefatiguelifeofthespecimens,theTaguchiorthogonaldesignmethodwasappliedinthesimulationdesign.Thesimulatingresultindicatedthatinfluenceofthesheetthicknessonfatiguelifewasthemostsignificant.Inaddition,theeffectsofnuggetdiameter,sheetwidthandoverlappinglengthonfatiguelifewerereducedinturn.