深冲汽车薄板脉冲激光焊接拼焊接头的组织与性能

安徽工业大学毕业设计（论文）报告纸共2页第1页┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊深冲汽车薄板脉冲激光焊接拼焊接头的组织与性能摘要本文采用小功率的SW500型Nd：YAG固体脉冲激光器对0.7mm厚的DC06冷轧薄钢板进行等厚板焊接研究，利用VHX-900型数码显微镜、金相显微镜,对焊接接头的表面成形性和微观组织进行分析，利用显微硬度计、拉伸试验机、杯突试验机进行拼焊板的力学和成型性能试验研究。研究结果表明：在其他工艺参数一定的条件下，随着焊接速度的增加，焊缝凹陷率、热影响区宽度和焊缝搭接率减小，焊接速度为400mm/min的成形性比较好。焊缝和热影响区的组织都是粗大的不规则的铁素体，随着焊接速度的增加，焊缝和热影响区的晶粒都减小，硬度都升高，而且焊缝的升高趋势比较明显，在速度为500mm/min时，焊缝与热影响区的硬度基本差不多。拼焊板的抗拉强度和延伸率低于母材，杯突成型性能比母材低，但是差厚拼焊板接头性能仍能满足汽车板的使用性能要求。关键词：汽车薄板；脉冲激光；显微组织；力学性能安徽工业大学毕业设计（论文）报告纸共2页第2页┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊Themicrostructureandpropertiesofpulsedlaserweldingwithtailorweldedblanksforautomotivedeep-drawingsteelAbstractInthispaper,aSW500Nd:YAGlow-powerpulsedlaserisusedtoweldcoldrolledsteelsheet0.7mmDC06,researchonthesamethicknessplateswelding.ThesurfacemorphologyandmicrostructureofjointshavebeeninvestigatedbymeansofVHX-900digitalmicroscope,opticalmicroscope.Themechanicalpropertiesandformingpropertiesofjointshavebeenstudiedbymeansofmicro-hardnesstester,tensiletestingmachineandcuppingtestmachine.Theresultshowsthatwiththeincreaseofweldingspeed,butotherparametersundercertainconditions,Weldsagratio,thewidthofheataffectedzoneandweldoverlayratearealsoreduces.Theweldformabilitywasthebestwhentheweldingspeedisselectedon400mm/min,ThemicrostructureofweldandHAZarebothrelativelycoarseirregularmassiveferrite.Withtheincreaseofweldingspeed,themicrohardnesswereelevatedandtherisingtrendofweldismoreapparent.Whentheweldingspeedisselectedon500mm/min，themicrohardnessofweldandHAZaresame.ThetensilestrengthandelongationofTWBarebelowbasematerial.AndthecuppingformingpropertyofTWBisworsethanthebasematerial.Buttheweldedjointsofdifferent-thickplateisstillmettheusingrequirementsofautoplates.Keywords:autoplate;pulsedlaser;microstructure;mechanicalproperties安徽工业大学毕业设计（论文）报告纸共2页第1页┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊目录引言..................................................................................................................................11文献综述..............................................................................................................................21.1激光焊接的基本原理和特点..................................................................................21.1.1激光焊接的基本原理....................................................................................21.1.2激光焊接的特点............................................................................................21.2激光焊接的设备和工艺参数..................................................................................41.2.1激光焊接的设备............................................................................................41.2.2激光焊接工艺参数........................................................................................41.3汽车用高强度钢板...................................................................................................81.3.1高强度钢板的分类........................................................................................91.3.2高强度钢板的特点......................................................................................101.3.3高强度钢板的强化机制..............................................................................121.4激光焊接在汽车工业中的应用............................................................................131.4.1汽车工业的激光焊接..................................................................................131.4.2汽车用深冲拼焊板的激光焊接.................................................................141.4.3汽车零部件的激光焊接..............................................................................151.5激光焊接国内外研究现状....................................................................................171.5.1激光焊接国内研究现状..............................................................................171.5.2激光焊接国外研究现状..............................................................................181.5.3激光焊接的未来发展趋势..........................................................................181.6本课题的研究内容.................................................................................................192试验材料与方法................................................................................................................202.1试验材料.................................................................................................................202.2试验设备.................................................................................................................202.2.1激光焊接设备..............................................................................................202.2.2超景深数码显微镜......................................................................................212.2.3显微维氏硬度计..........................................................................................21安徽工业大学毕业设计（论文）报告纸共2页第2页┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊2.2.4拉伸试验机...................................................................................................212.2.5多功能板料成形试验机..............................................................................212.3试验方法......................................................................