镁-裸钢板异种金属冷金属过渡熔钎焊连接机理  

Joining mechanisms of cold metal transfer welding-brazing of Mg to bare steel

作　　者：朱海霞[1] 曹睿[1] 李雅范 林巧力[1] 陈剑虹[1] 

机构地区：[1]兰州理工大学有色金属先进加工与再利用省部共建国家重点实验室,兰州730050 [2]哈尔滨电气动力装备有限公司,哈尔滨150000

出　　处：《焊接学报》2016年第5期77-80,132,共4页Transactions of The China Welding Institution

基　　金：973计划前期研究专项(2014CB660810);国家自然科学基金资助项目(51265028)

摘　　要：以AZ61镁合金焊丝为填充材料,对AZ31B镁合金/Q235裸钢板进行冷金属过渡熔钎焊试验研究,分析不同工艺参数对焊缝成形和力学性能的影响.并通过分析焊接接头微观组织及其元素分布状况来研究其连接机理.研究结果表明:随着送丝速度的增加,接头最大抗拉载荷先升高后降低,当焊缝宽度较大时,断裂易发生在镁的热影响区,其最大抗拉载荷可达6 k N以上;焊缝及镁合金中的Al原子通过焊接过程扩散到界面上形成很薄的Fe-Al相反应层,从而实现了镁、裸钢板的有效连接.AZ31B magnesium alloys and Q235 bare steel are joined by cold metal transfer process with AZ61 Mg based filler wire. The effects of processing parameters on weld appearance and mechanical properties are studied. The joining mechanism is studied by analyzing the microstructure and distribution of elements of welded joints. The results indicate that the tensile strength of the joints first increased and then decreased with the increase of the wire feed speed. The joint with larger weld width is fractured in the magnesium heat affected zone and has a tensile load more than 6 kN. Mg and bare steel can be efficiently joined by the thin interfacial reaction layers with Fe-Al phase,which is attributed to the diffusion of the element Al.

关 键 词：冷金属过渡焊 镁/裸钢板 接头强度 

分 类 号：TG456.9[金属学及工艺—焊接]