5083铝合金MIG焊接头微观组织与力学性能  

Microstructure and mechanical properties of 5083 aluminum alloy with MIG welding

作　　者：王家威 吴巍[2] 马月婷 黄立兵 董红刚[1] Wang Jiawei;Wu Wei;Ma Yueting;Huang Libing;Dong Honggang(Dalian University of Technology,Dalian 116024,Liaoning,China;Baoshan Iron&Steel Co.,Ltd.,Baosteel Central Research Institute,Shanghai 200431,China)

机构地区：[1]大连理工大学,辽宁大连116024 [2]宝山钢铁股份有限公司,宝钢中央研究院,上海200431

出　　处：《焊接》2022年第11期20-28,53,共10页Welding & Joining

摘　　要：采用熔化极惰性气体保护焊开展了6 mm厚5083-H111铝合金热轧板焊接工艺试验,研究了接头宏观形貌和力学性能随工艺参数的变化规律,分析了不同区域的微观组织和元素分布对接头力学性能的影响。结果表明,采用优化后的工艺参数进行焊接,得到的接头表面成形良好,无明显缺陷。随着送丝速度增加,焊缝宽度随之增加;熔合线附近的热影响区发生完全再结晶,形成了粗大的等轴晶;焊缝边缘沿散热方向形成柱状晶,焊缝中心则为细小的等轴晶组织;Fe和Mn在热影响区偏聚严重,形成Al6(Fe, Mn)相,焊缝中Mg主要分布在晶界处,形成β(Al3Mg2)相。拉伸试验结果表明,接头最大抗拉强度可达307 MPa,约为母材抗拉强度的96%,拉伸后断裂于热影响区,呈韧性断裂;受焊接热输入影响,焊缝和热影响区的硬度低于母材,随着焊接热输入增加,焊缝和热影响区的硬度降低。The welding experiment of 6 mm thick 5083-H111 aluminum alloy hot rolled plate was carried out by metal inert gas welding. The variation of macro morphology and mechanical properties of joints with different process parameters was studied, and the effect of microstructure and element distribution in different regions on mechanical properties of the joint was analyzed. The results showed that the surface of all joints with optimized process parameters had no obvious defects. The weld width increased with the increase of wire feeding speed. Complete recrystallization occurred in heat-affected zone near the fusion line, and coarse equiaxed crystals were formed. The edge of the weld formed columnar crystals along the heat dissipation direction, and the fine equiaxed crystals were found in the center of the weld. Fe and Mn were seriously segregated in the heat-affected zone, forming Al6(Fe, Mn) phase. Mg is mainly distributed in the grain boundary of the weld and formed β(Al3Mg2) phase. The tensile test results showed that the maximum tensile strength of the joint could reach 307 MPa, which was about 96% of the base metal, and the fracture occurred in heat-affected zone with ductile fracture. Affected by the welding heat input, the hardness of the weld and heat-affected zone were lower than that of the base metal. With the increase of welding heat input, the hardness of the weld and heat-affected zone decreased.

关 键 词：5083-H111铝合金 MIG焊 微观组织 力学性能 

分 类 号：TG442[金属学及工艺—焊接]