摘要
采用电阻点焊对MB3镁合金和镀锌钢板进行了焊接,研究了焊接电流对镁/钢接头宏观形貌、微观组织及力学性能的影响。试验结果表明：镁/钢点焊接头熔核直径及压下率随焊接电流增大而增大,接头拉剪载荷随电流增大呈先增大后减小的趋势。当焊接电流为13 k A,焊接时间为10周波,电极压力为5 k N时,接头拉剪力达到最大值6.1k N,此时点焊接头表现为纽扣式断裂。Fe与Al在镁/钢界面处发生反应生成Fe-Al化合物,其显微硬度达到146 HV。
The MB3 magnesium alloy and galvanized steel were joined by using resistance spot welding, and the effects of welding current on the joint appearance, microstructure and mechanical properties were studied. The results show that the nugget diameter and reduction rate of the Mg/Steel spot welded joint increase with the increase of welding current, while the tensile-shear load of the joint increases firstly and then decreases. When the welding current is 13 k A, welding time is 10 cycles and electrode pressure is 5 k N, the tensile-shear load of the joint is maximum, which is 6.1 k N, and the failure of the spot welded joint is nugget pulling out. Besides, Fe-Al intermetallic compound is formed at the Mg/Steel interface, and the interfacial microhardness reaches 146 HV.
作者
汤贵庭
TANG Guiting(College of Intelligent Manufacturing and Automobile,Chongqing Radio and Television University,Chongqing 401520,China)
出处
《热加工工艺》
CSCD
北大核心
2018年第15期225-228,共4页
Hot Working Technology
基金
重庆市青年骨干教师资助项目(No.2007-49)
重庆市十三五规划项目(No.2016-GX-192)
关键词
镀锌钢
镁合金
电阻点焊
微观组织
拉剪载荷
galvanized steel
magnesium alloy
resistance spot welding
microstructure
tensile-shear load
