DP590与低碳钢激光拼焊板力学性能及微观结构研究(英文)  

Microstructures and Mechanical Properties for Laser Tailor Welded Blanks of DP590 and Low Carbon Steels

作　　者：韦春华[1] 张婧 杨上陆 陶武[1] 吴丰顺[1] 夏卫生[1] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,湖北武汉430004 [2]通用汽车中国科学研究院,上海201206

出　　处：《稀有金属材料与工程》2013年第S2期68-73,共6页Rare Metal Materials and Engineering

基　　金：NSFC(50824001)

摘　　要：主要研究双相高强钢DP590和IF低碳钢激光拼焊板接头的组织和力学性能。在DP590与DP590拼焊接头中,由于焊缝中大量马氏体的形成导致其硬度显著增加,而HAZ除了在局部软化区外都具有比母材更高的硬度。DP590和IF钢拼焊接头的焊缝主要由铁素体和粒状贝氏体组成,无马氏体存在,其硬度最高值出现在DP590侧的熔合线附近。两种拼焊板与母材相比,横向接头都具有较低的强度和延伸率,而纵向接头具有较高强度和较低延伸率。同时,采用微小试样单向拉伸实验结合混合规则理论计算,分别获得了焊缝金属和HAZ力学性能,结果表明焊缝金属具有高的强度及非常低的延展性,接头拉伸时变形主要集中于强度较低的母材。而HAZ是影响纵向接头力学性能的一个重要因素,HAZ具有介于母材及焊缝之间的性能,HAZ局部软化区域并没有显著影响接头的力学性能。This research characterizes the microstructures and mechanical properties of laser TWBs of DP590 and DP590,DP590 and IF steel(a low carbon steel).For the joint of DP590 and DP590,the laser welding results in a significant increase of microhardness in the weld caused by the formation of martensite in large quantity.HAZ shows a relatively higher microhardness than that of the base metal except for the local softened zones.But no martensite is observed in the weld of DP590 and IF steel,which is mainly composed of ferrite and granular bainite.Highest microhardness is observed at the fusion line of DP590 side.For both of the two TWBs,the transverse joints have the lower strength and elongation,and the longitudinal joints show the higher strength and lower elongation than those of the base metals.The properties of weld metal and HAZ are obtained by the miniature sample testing,and also the theoretical results of HAZ properties are calculated based on the rule of mixture.It is concluded that the weld metal has limited ductility,and the deformation of the joint is concentrated on the base metal.HAZ plays an important part in the joint properties,but its softening does not seriously affect the mechanical properties.

关 键 词：拼焊板 激光焊接 DP590 低碳钢 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]