简介：AnewsimulationmodelofCO2short-circuitingtransferweldingmaybeemployedtodevelopanewpatternofweldingmachineandtopredictweldingprocessparameterstoobtaintheoptimumweldingtechnologyproperties.Inthispaper,anewsimulatingmodelisdevelopedaccordingtotheAWP(adaptingweldingphysicsprocess)waveformcontrolmethod.Goodagreementisshownbetweenthepredictedandexperimentallydeterminedresults.ThemodelwillmakeanimportantpromotioninthedevelopmentofCO2arcweldingtechnique.

简介：Anewhardfacingprocess,reactivebrazecoatingprocess(RBCC)wasstudied,and(TiC+Cr3C2)/FecompositecoatingswerepreparedbyRBCCusingcarbon,Cr3C2,iron,ferrochromiumandtitaniumpowderastherawmaterialsinvacuumbrazefurnace.TheresultsshowthatTiCisin-situsynthesizedinthecoatings.ThemethodsofintroducingCr3C2havegreateffectsonthedistributionofTiC.AddingCr3C2directlytotherawmaterialsforcoatings,fineTiCparticlesaggregateintodiscoidsparalleltothecoatingsurface,whereas,in-situsynthesizingCr3C2incoatings,theaggregationsofTiCarelumpish.Duringbrazecoating,Cr3C2particlesdirectlyaddeddissolveandprecipitatetobecomeneedle-shaped.Thecoatingshaveanevenandsmoothsurfaceandarecombinedwiththeirmildsteelsubstratesbyametallurgicalbonding.

简介：CO2气体保护焊具有效率高、成本低、应用范围广等优点,且随着CO2焊接设备、焊接材料和焊接工艺的研究发展,使CO2气体保护焊在矿用汽车工业中获得广泛应用。

简介：Laserblankweldingisbecomingmoreandmoreimportantintheautomotiveindustryandthequalityoftheweldiscriticalforasuccessfulapplication.Afullyautomatedsolutionisrequiredtoinspectthequalityoftheblanks.ThispaperpresentsavisioninspectionsystemwithaCMOScamerawhichusesART2networktoinspectthedefectson-linetoobtainthegeometryandthequalityoftheweldseam.TheneuralnetworkART2hasthecapabilityofself-learningfromtheenvironment.Itcandistinguishthedefectsthathavebeenlearnedbeforeandgivenewoutputsfornewdefects.SoART2networkissuitableforweldqualityinspectioninlaserblankwelding.Additionally,aCO_2laserisusedfortheblankbutt-welding.

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简介：Bead-on-plateCO2laserweldingof1000MPagradetransformationinducedplasticity(TRIP)steelwasconductedunderdifferentweldingpowers,weldingspeedsandshieldgases.Themacrostructuralandmicrostructuralfeaturesoftheweldedjointwereinvestigated.Theincreaseofweldingspeedreducedthewidthoftheweldbeadandtheporositiesintheweldbeadresultingfromthedifferentflowmodeofmeltedmetalinweldpool.ThedecreaseofweldingpoweroruseofshieldgasofheliumalsocontributedtothereductionofporosityinBead-on-plateCO2laserweldingof1000MPagradetransformationinducedplasticity(TRIP)steelwasconductedunderdifferentweldingpowers,weldingspeedsandshieldgases.Themacrostructuralandmicrostructuralfeaturesoftheweldedjointwereinvestigated.Theincreaseofweldingspeedreducedthewidthoftheweldbeadandtheporositiesintheweldbeadresultingfromthedifferentflowmodeofmeltedmetalinweldpool.Thedecreaseofweldingpoweroruseofshieldgasofheliumalsocontributedtothereductionofporosityintheweldbeadduetothealleviationofinducedplasmaformation,thusstabilizingthekeyhole.TheporosityformationintimatelycorrelatedwiththeevaporationofalloyelementMninthebasemetal.Thelaserweldedmetalhadsamemartensitemicrostructureasthatofwater-quenchedbasemetal.Theweldingparameterswhichincreasedcoolingrateallledtofinemicrostructuresoftheweldbead.

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简介：Theobjectiveofthisstudyistoinvestigatetheinfluenceofaddingtinyamountofmixedrareearth(La,Ce)andSrtoAl-20Cu-5Si-2Nifillermetal,byanalyzingthemicrostructure,wettabilityandmechanicalpropertiesofbrazedjoints.Theresultsshowthawiththeadditionofmixedrareearth(La,Ce)intoAl-20Cu-5Si-2Nialloy,theα-AlsolidsolutionaswellasCuAl_2(Ni)intermetalliccompoundphasesignificantlyreduced,whilemoreAl-SieutecticphaseandAl-Si-Cuternaryeutecticphasewereproduced.Andasmixedrareearth(La,Ce)addedin,thewettabilityofAl-20Cu-5Si-2Nifillermetaldecreased,whiletheshearstrengthofthebrazedjointsincreased.TheadditionofMinorSrmodificatedAl-20Cu-5Si-2Nifillermetal,furtherreducedtheCuAl_2(Ni)intermetalliccompoundphase,whichwaspartiallyreplacedAl-Si-Cuternaryeutecticphase.Asaresult,thetensilestrengthaswellasthewettabilityofthefillermetalwasimproved.

简介：LaserweldingwithfillerwireofAZ31magnesiumalloysisinvestigatedusingaCO2laserexperimentalsystem.Theeffectofthreedifferentfillerwiresonthejointpropertiesisresearched.Theresultsshowthattheweldappearancecanbeeffectivelyimprovedwhenusinglaserweldingwithfillerwire.ThemicrohardnessandtensilestrengthofjointsarealmostthesameasthoseofthebasemetalwhenERAZ31orERAZ61wireisadopted.However,whenthefillerwireofER5356aluminumalloyisused,themechanicalpropertiesofjointsbecomeworse.ForERAZ31andERAZ61fillerwires,themicrostructureofweldzoneshowssmalldendritegrains.Incomparison,forER5356fillerwire,theweldshowsastructureofsnowydendritesandmanyintermetalliccompoundsandeutecticphasesdistributeinthedendrites.Theseintermetallicconstituentswithlowmeltingpointincreasethetendencyofhotcrackandresultinfragilejointproperties.Therefore,ERAZ31andERAZ61wirearemoresuitablefillermaterialthanER5356forCO2laserweldingofAZ31magnesiumalloys.

简介：ThedistributionsoftheaxialstressandshearstressinAl2O3-TiC/Q235diffusionbondedjointswerestudiedusingfiniteelementmethod(FEM).Theeffectofinterlayerthicknessontheaxialstressandshearstresswasalsoinvestigated.Theresultsindicatethatthegradientsoftheaxialstressandshearstressaregreatnearthejointedge.ThemaximalshearstressproducesattheinterfaceoftheAl2O3-TiCandTiinterlayer.WiththeincreaseofCuinterlayerthickness,themagnitudesoftheaxialstressandshearstressfirstdecreaseandthenincrease.Thedistributionoftheaxialstresschangesgreatlywithalittlechangeintheshearstress.TheshearfractureinitiatesattheinterfaceoftheAl2O3-TiC/TiinterlayerwithhighshearstressandthenpropagatestotheAl2O3-TiCside,whichisconsistentwiththestressFEMcalculatingresults.

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简介：Thispaperintroducedthebasictheoryandalgorithmofthesurrogatedatamethod,whichproposedarigorouswaytodetecttherandomandseeminglystochasticcharacteristicsinasystem.TheGaussiandataandtheRosslerdatawereusedtoshowtheavailabilityandeffectivityofthismethod.Accordingtotheanalysisbythismethodbasedontheshort-circuitingcurrentsignalsundertheconditionsofthesamevoltageanddifferentwirefeedspeeds,itisdemonstratedthattheelectricalsignalstimeseriesexhibitapparentlyrandomnesswhentheweldingparametersdonotmatch.However,theelectricalsignalstimeseriesaredeterministicwhenamatchisfound.Thestabilityofshort-circuitingtransferprocesscouldbejudgedexactlybythemethodofsurrogatedata.

简介：ThesusceptibilityofweldedjointfortheX65pipelinesteeltoH2Sstresscorrosioncracking(SCC)isinvestigated.SCCtestsonthesteelarecarriedoutintheenvironmentbasedonNACETM-01-77solutionwithsaturatedgaseousH2S.Thethresholdstressintensityfactorandcrackpropagationvelocityarecalculatedaccordingtowedge-openingloading(WOL)specimens.Thethree-dimensionalelastic-plasticfiniteelementanalysisofWOLspecimensisperformedbyusingtheFEMprogrammingpackageANSYS.Stressfieldandconcentrationofhydrogendistributionpropertyaheadofthecracktipareobtained.ThispapersurveyedthemicrostructureofweldedjointandstudiedonthemechanicalpropertiesofX65pipelinesteel.Itprovidesexperimentalbasisforstudyingstresscorrosion.Theresultsofnumericalanalysisareconsistentwithconclusionsofstresscorrosiontest.

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