6N01S-T5铝合金高速激光-MIG复合焊接工艺

Investigation on high speed laser-MIG hybrid welding process of 6N01S-T5 aluminum alloy

关键词:  激光-MIG复合焊  6N01铝合金  高速焊接  焊接变形  残余应力

Key words:  laser-MIG hybrid welding  6N01S-T5 aluminum alloy  high speed welding  welding distortion  residual stress

摘要:

针对高速列车侧墙6N01S-T5铝合金熔化焊时存在焊接变形大，接头软化严重等问题，提高激光-MIG复合焊的焊接速度降低热输入，并通过显微硬度、拉伸试验测试，结合金相及扫描电镜下的EDS分析，对比了高、低焊接速度两种工艺下接头力学性能及微观组织的差异；采用三坐标测量仪和X射线残余应力测试仪对试样焊接变形和残余应力进行测试分析.结果表明，当焊接速度达到4.8 m/min时焊缝仍能保证较好的成形；相比于0.6 m/min低速焊接，焊接效率大幅度提高，焊缝金属填充量减少68%，接头软化区宽度减小约60%；试件焊后变形及高应力分布区域变窄；焊缝组织细密，接头平均抗拉强度为207 MPa，达到母材强度的71%.

Abstract:

To reduce the welding distortion and joint softening defects of 6N01S-T5 aluminum alloy, high-speed (4.8 m/min) laser-MIG hybrid welding process is performed. The mechanical properties and microstructure of welded joints are analyzed by microhardness test, tensile test, metallographic and SEM with EDS. The welding distortion of the butt joint is tested by coordinate measuring apparatus. The residual stress is measured by X-ray residual stress measurement instrument. The results show that the good appearance of weld is attained at the welding speed of 4.8 m/min. The average tensile strength of the high speed welding joint is 207 MPa, which is 71% of the base metal. Compared with the low speed welding process, the welding wire consumption is reduced by 68% and the welding efficiency is greatly improved at high speed welding process. Meanwhile, the width of the joint softening zone is reduced by 60%. The welding distortion is smaller and the range of residual tensile stress is narrower.