V形耦合双热源自熔焊接热-力分布特征  

Thermal-Stress Distribution Characteristics of V-Shaped Coupling Bilateral Heat Source Autogenous Welding

作　　者：强伟 王克鸿[2] 彭勇[2] 袁银辉[1] 路永新 董会 Qiang Wei;Wang Kehong;Peng Yong;Yuan Yinhui;Lu Yongxin;Dong Hui(School of Materials Science and Engineering,Xi'an Shiyou University,Xi'an 710065,China;Key Laboratory of Controlled Arc Intelligent Additive Manufacturing,Ministry of Industry and Information Technology,Nanjing University of Science and Technology,Nanjing 210094,China;State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]西安石油大学材料科学与工程学院,陕西西安710065 [2]南京理工大学受控电弧智能增材技术工业与信息化部重点实验室,江苏南京210094 [3]哈尔滨工业大学先进焊接与连接国家重点实验室,黑龙江哈尔滨150001

出　　处：《稀有金属》2024年第4期529-538,共10页Chinese Journal of Rare Metals

基　　金：陕西省教育厅科研计划项目(21JK0833);陕西省自然科学基础研究计划项目(2020JQ-768);控电弧智能增材技术工业与信息化部重点实验室创新基金项目(CAIAM-202101);先进焊接与连接国家重点实验室开放课题研究基金项目(AWJ-21M21)资助。

摘　　要：通过数值模拟研究了V形耦合双热源焊接和单热源次序焊接T形接头的热场与力场特征,对比了不同电流下V形耦合双热源焊缝的几何特征参数变化,并分析了其气孔产生机制和微观组织特征。结果表明,V形耦合双热源焊接的热循环曲线为“单峰”状,而单热源次序焊接的热循环曲线为“双峰”状;单热源次序焊接测点的最高温度较V形耦合双热源焊接低16℃,而V形耦合双热源焊接的冷却速度高于单热源次序焊接。T形接头耦合双热源焊接的翼板纵向残余应力呈对称M状分布,近缝区为拉应力,远缝区为压应力,腹板顶部为压应力,底部为拉应力;T形接头单热源次序焊接的纵向残余应力分布规律与耦合双热源焊接类似,但翼板的纵向残余应力呈非对称M状分布。耦合双热源焊缝截面的几何特征参数与电流呈正相关,T形接头顶端部位易产生密集气孔缺陷,焊缝组织主要由α-Al,β(Al_(3)Mg_(2))和Mg_(2)Si相组成。With the demand of car lightweight,aluminium alloy T-joint was widely applied in the automotive industry.Different from laser beam welding and friction stir welding on T-joint,which required precise assembly and back support of workpiece,the arc welding technology possessed the advantages of flexibility and convenience.Using conventional arc welding for T-joint needed a series of processes,including groove processing,one side welding,back gouging,nondestructive test,the other welding,etc.Therefore,a V-shaped coupling bilateral heat source welding(VCBHSW)process was proposed,referring to a welding method in which two gas tungsten arc welding arcs were symmetrically arranged on both sides of the T-joint with a certain angle between the heat source axes,and the dual heat sources were welded in the same direction at the same speed.The angle between the heat source axis and the web was42°,and the autogenous welding without wire filling was adopted.VCBHSW process could reduce processes and improve efficiency compared with conventional arc welding.Numerical simulation and experiment were carried out on VCBHSW process to investigate the thermal,force field characteristics,morphology,and microstructure of T-joint assembled by 5083 aluminum alloy plate with thickness of 8 mm.Pure argon protection was adopted in welding experiment,and the gas flow was 11 L·min^(-1).Four welding parameters were employed with a series of welding current(205,207,210 and 220 A)under other fixed parameters.The rationality of heat source model and parameter setting was verified by fusion line contour method.Stereo microscope was used to observe the cross-section morphology of T-joint,and the geometric characteristic parameters of joint were quantitated.The optical microscope was applied to observe the microstructure and pore defects of the T-joint.To illustrate the characteristics of VCBHSW,the single heat source sequential welding(SHSSW)was used as a control group.The results showed that the thermal cycle curve of VCBHSW process was unimodal,a

关 键 词：V形耦合双热源焊接 单热源次序焊接 T形接头 热场 力场 微观组织 

分 类 号：TG444[金属学及工艺—焊接]