高速列车6005A铝合金型材焊接热裂纹分析  

Weld hot crack analysis of 6005A aluminum alloy profile for high-speed train

作　　者：张健[1] 雷振[1] 王旭友[1] 

机构地区：[1]机械科学研究院哈尔滨焊接研究所,哈尔滨150080

出　　处：《焊接学报》2012年第8期60-64,116,共5页Transactions of The China Welding Institution

基　　金：国际科技合作基金资助项目(2009DFR50170);国际科技合作基金资助项目(2008BR0002);国际科技合作基金资助项目(2010DFR50770);国家863高技术研究发展计划资助项目(2012AA040208)

摘　　要：利用热塑性试验研究了6005A铝合金的热裂纹敏感性,分析了激光-MIG复合热源焊接6005A铝合金型材的焊接热裂纹问题.热塑性试验结果表明,6005A铝合金的脆性温度区间为550～640℃,具有较高的热裂纹敏感性.利用激光-MIG复合焊,采用I形坡口,可以在4.5 m/min的焊接速度下实现6005A铝合金型材的高速焊接.获得的复合焊缝背面局部区域出现垂直于焊缝的热裂纹.热裂纹产生的原因是由更改坡口后致使焊缝金属中母材的稀释率增大引起的,采用适当角度的V形坡口可以消除激光-MIG复合焊中的热裂纹.The hot cracking sensibility of 6005A aluminum alloy was investigated with hot plasticity test,and the weld hot crack of 6005A aluminum alloy profile in laser-MIG hybrid welding was analyzed.Hot plasticity test results indicated that the brittle temperature range(BTR) of 6005A aluminum alloy was 550-640 ℃,which demonstrated that the hot cracking sensibility of the aluminum alloy was high.High-efficient welding of 6005A aluminum alloy profile can be achieved by utilizing laser-MIG hybrid welding process with I groove and welding speed up to 4.5 m/min.However,hot crack perpendicular to weld bead was found on the back of weld.The increase of dilution rate,caused by changing the groove,was the main reason for the generation of hot crack on the back of weld made by laser-MIG hybrid welding.However,the hot crack can be avoided by using V groove instead of the I groove in the hybrid welding of 6005A aluminum alloy profile.

关 键 词：铝合金型材 脆性温度区间 热裂纹 激光 复合热源 

分 类 号：TG456.9[金属学及工艺—焊接]