简介:Laserblankweldingisbecomingmoreandmoreimportantintheautomotiveindustryandthequalityoftheweldiscriticalforasuccessfulapplication.Afullyautomatedsolutionisrequiredtoinspectthequalityoftheblanks.ThispaperpresentsavisioninspectionsystemwithaCMOScamerawhichusesART2networktoinspectthedefectson-linetoobtainthegeometryandthequalityoftheweldseam.TheneuralnetworkART2hasthecapabilityofself-learningfromtheenvironment.Itcandistinguishthedefectsthathavebeenlearnedbeforeandgivenewoutputsfornewdefects.SoART2networkissuitableforweldqualityinspectioninlaserblankwelding.Additionally,aCO_2laserisusedfortheblankbutt-welding.
简介:Bead-on-plateCO2laserweldingof1000MPagradetransformationinducedplasticity(TRIP)steelwasconductedunderdifferentweldingpowers,weldingspeedsandshieldgases.Themacrostructuralandmicrostructuralfeaturesoftheweldedjointwereinvestigated.Theincreaseofweldingspeedreducedthewidthoftheweldbeadandtheporositiesintheweldbeadresultingfromthedifferentflowmodeofmeltedmetalinweldpool.ThedecreaseofweldingpoweroruseofshieldgasofheliumalsocontributedtothereductionofporosityinBead-on-plateCO2laserweldingof1000MPagradetransformationinducedplasticity(TRIP)steelwasconductedunderdifferentweldingpowers,weldingspeedsandshieldgases.Themacrostructuralandmicrostructuralfeaturesoftheweldedjointwereinvestigated.Theincreaseofweldingspeedreducedthewidthoftheweldbeadandtheporositiesintheweldbeadresultingfromthedifferentflowmodeofmeltedmetalinweldpool.Thedecreaseofweldingpoweroruseofshieldgasofheliumalsocontributedtothereductionofporosityintheweldbeadduetothealleviationofinducedplasmaformation,thusstabilizingthekeyhole.TheporosityformationintimatelycorrelatedwiththeevaporationofalloyelementMninthebasemetal.Thelaserweldedmetalhadsamemartensitemicrostructureasthatofwater-quenchedbasemetal.Theweldingparameterswhichincreasedcoolingrateallledtofinemicrostructuresoftheweldbead.
简介:本文针对N4/1Cr18Ni9Ti与N4/0Cr25Ni20复合板的特殊焊接要求,根据NB/T47014—2011《承压设备焊接工艺评定》的要求,制备2块N4/1Cr18Ni9Ti试板,2块N4I/0Cr25Ni20试板,尺寸均为500mmX150mmX(4+14)mm。不锈钢基层采用GTAW打底,焊丝选用HOCr21Ni10,SMAW填充与盖面,焊条选用A302与A402。镍复层的焊接采用手工钨极氩弧焊,焊丝选用含Ti、AI等脱氧元素的ERNi-1焊丝,保护气体选择98%Ar+2%H2。试板焊接完成,外观检验合格后进行100%RT,检测结果符合JB厂r4730,2—2005I级合格,镍复层进行100%PT,检测结果符合JB/T4730.5—2005I级。两种焊接试板分别取样并做拉伸、弯曲力学性能分析,镍复层焊缝做化学成分分析。通过两块焊接试板试验对比,不锈钢基层焊接材料选择HOCr21Ni10焊丝与A302焊条。镍复层焊接采用ERNi-1焊丝,焊接保护气体为98%Ar+2%H2。通过焊接工艺评定试验研究,解决了N4/1Cr18Ni9Ti与N4I/0Cr25Ni20复合板焊接问题,提高了用户坩埚的返修质量与再次使用寿命,为使用单位节约了成本。
简介:Duetothedisturbancesofspatters,dustsandstrongarclight,itisdifficulttodetectthemoltenpooledgeandtheweldlinelocationinCO2weldingprocesses.Themedianfilteringandself-multiplicationwasemployedtopreprocesstheimageoftheCO2weldinginordertodetecteffectivelytheedgeofmoltenpoolandthelocationofweldline.TheB-splinewaveletalgorithmhasbeeninvestigated,theinfluenceofdifferentscalesandthresholdsontheresultsoftheedgedetectionhavebeencomparedandanalyzed.TheexperimentalresultsshowthatbetterperformancetoextracttheedgeofthemoltenpoolandthelocationofweldlinecanbeobtainedbyusingtheB-splinewavelettransform.Theproposededgedetectionapproachcanbefurtherappliedtothecontrolofmoltendepthandtheseamtracking.
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:ComparisonofmechanicalpropertiesinweldedjointforCO2arcweldingbyusingthemicro-sheartestandimpacttest¥ZhouLixia;WangShiyuanand?..
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.