5A06铝合金GMAW熔透接头组织与性能对比研究  

Comparative Study on Microstructure and Properties of 5A06 Aluminum Alloy Full-penetration Joint with Gas Metal Arc Welding Process

作　　者：姚尚坤 冯曰海[1] 黄俊[1] 王立新 赵斌彬 YAO Shangkun;FENG Yuehai;HUANG Jun;WANG Lixin;ZHAO Binbin(School of Materials and Engineering,Nanjng University of Science&Technology.Nanjng 210094,China;Technology Research Institute,Inner Mongolia First Machinery Group Company Limited,Baotou 014010,China)

机构地区：[1]南京理工大学材料科学与工程学院,江苏南京210094 [2]内蒙古第一机械集团股份有限公司工艺研究所,内蒙古包头014010

出　　处：《电焊机》2022年第11期52-60,共9页Electric Welding Machine

基　　金：国防创新项目(17-H863)。

摘　　要：针对5A06铝合金薄壁油箱焊缝形式多样、焊接效率低、难以实现焊接自动化等问题,采用AC-CMT、CMT、P-MIG和CMT+P四种GMAW工艺进行试验,并对比研究了四种工艺下的焊缝成形特征、气孔分布、显微组织和接头性能。结果表明,P-MIG接头的正面余高最小,熔透时所需热输入最低,焊缝纵截面和横截面观察区域内尺寸为10~100μm的气孔数量均最少;四种工艺接头焊缝区的显微组织均由α-Al基体和β-Al3Mg2析出相构成,相较于AC-CMT与CMT工艺,P-MIG与CMT+P接头焊缝区晶粒尺寸较大,热影响区宽度较宽;P-MIG接头抗拉强度最高(318 MPa),为母材的89.1%,且接头弯曲到180°时未开裂;P-MIG和AC-CMT拉伸断口无气孔,CMT与CMT+P接头拉伸与弯曲断口均可明显观察到较多气孔。综合比较,气孔最少、抗拉强度最高和弯曲性能较好的PMIG工艺更加适合5A06铝合金薄壁油箱的机器人自动化焊接。In order to solve the problems of the various weld forms, low welding efficiency and difficult to achieve welding automation of 5A06 aluminum alloy thin-walled fuel tank, four GMAW welding processes AC-CMT, CMT, P-MIG and CMT+P were studied. The difference in weld forming characteristics, pore distribution, microstructure, and joint properties of the four processes were compared and studied. The results show that the front reinforcement of the joint, the energy input required for penetration, and the number of pores in longitudinal and transverse section with P-MIG is the lowest. The microstructure of the weld zone of four process joints consisted of α-Al matrix and β-Al3Mg2, compared with AC-CMT and CMT processes, the grain size in the weld zone of P-MIG and CMT+P joints is larger and the width of heat affected zone is wider.The mechanical property test shows that the tensile strength of P-MIG joint is the highest(318 MPa), which is 89.1% of the base metal, and the joint still does not crack when the bending angle is 180° with P-MIG. SEM observation show that the tensile fracture surfaces does not exist pore with P-MIG and AC-CMT, and more pores could be observed on the tensile and bending fracture surfaces of CMT and CMT+P joints. By comprehensive comparison, the P-MIG process has the least pores,the highest tensile strength and better bending performance, which is more suitable for the robot automatic welding of 5A06aluminum alloy thin-walled fuel tank.

关 键 词：5A06铝合金 焊接工艺 显微组织 气孔 弯曲性能 机器人焊接 

分 类 号：TG457.14[金属学及工艺—焊接]