20mm厚铝合金激光-MIG复合打底焊工艺及组织性能  

Laser-MIG Hybrid Backing Welding Process of 20 mm Thick Aluminum Alloy and Structure Properties

作　　者：杨志斌 谢延祺 盛立康 Yang Zhibin;Xie Yanqi;Sheng Likang(School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,Liaoning,China)

机构地区：[1]大连交通大学材料科学与工程学院,辽宁大连116028

出　　处：《中国激光》2024年第20期1-11,共11页Chinese Journal of Lasers

基　　金：辽宁省教育厅科学研究基金(JDL2020026)。

摘　　要：针对20 mm厚6082-T6铝合金对接接头开展了激光-MIG复合打底焊(MIG,熔化极惰性气体)试验,研究了坡口形式对电弧行为、熔滴过渡和焊缝质量的影响,基于正交试验优化了焊接工艺参数,分析了打底焊接头的组织性能。结果表明:采用钝边高度为10 mm的U形坡口获得的焊缝成形质量优且焊接过程稳定;关键工艺参数对焊缝质量的影响从强到弱排列依次是焊接速度、电弧电流、激光功率、弧长修正;焊缝电弧主要作用区中柱状晶区的宽度小于激光主要作用区中柱状晶区的宽度,但电弧主要作用区中部分熔化区的宽度大于激光主要作用区中部分熔化区的宽度;接头的显微硬度最低值出现在热影响区;打底焊接头的平均抗拉强度为221.6 MPa,为母材的75.1%;打底焊接头的抗应力腐蚀敏感指数为0.024;拉伸试样和抗应力腐蚀试样的断裂位置均位于热影响区,断裂路径均平行于熔合线,断口形貌均呈典型的塑性断裂特征。Objective The heat-treatable aluminum alloy is widely used in the high-speed train body manufacturing industry owing to its low density and high specific strength.In the current high-speed train manufacturing industry,metal inert gas(MIG)welding and friction stir welding are the most commonly used welding techniques for medium-thick aluminum alloys.However,these two welding methods exhibit certain limitations.Laser-MIG hybrid welding combines the advantages of laser and MIG welding,and is a promising welding technology for joining aluminum alloy components.Many investigations have shown that it has several typical technical advantages such as faster welding speed,deeper weld penetration,lower heat input,smaller welding deformation,narrower heataffected zone,and better mechanical properties.Currently,there are few research reports on laser-MIG hybrid multipass welding for medium-thick aluminum alloys;however,this welding technique is urgently needed in the high-speed manufacturing industry.Laser-MIG hybrid backing welding is a key step in laser-MIG hybrid multipass welding technology and has crucial effects on the weld formation and mechanical properties of weld joints.Therefore,in this study,the laser–MIG hybrid backing welding of a 20 mm thick 6082-T6 aluminum alloy is studied.Methods Laser-MIG hybrid backing welding is performed on 20 mm thick 6082-T6 aluminum alloy butt joints.The influence of the groove shapes on the arc behavior,droplet transfer,and weld formation is studied using a high-speed camera.The influence of groove form and size on weld formation is analyzed.Based on the optimized groove form,an orthogonal test is used to optimize the welding process parameters,and the primary and secondary orders of influence of the process parameters on weld formation are obtained.Finally,the microstructural characteristics and mechanical properties of the joints are investigated under the optimal parameters.Results and Discussions The U-groove and V-groove have almost similar arc behaviors and droplet transitio

关 键 词：激光技术 激光-MIG复合焊接 打底焊 铝合金 组织性能 

分 类 号：TG456.7[金属学及工艺—焊接]