焊丝对2A12铝合金焊接接头组织和力学性能的影响

Effects of Welding Wires on Microstructure and Mechanical Properties of 2A12 Aluminum Alloy Welded Joints

对2A12铝合金进行交流钨极氩弧焊接,探讨了ER4043焊丝和BJ-380A焊丝对焊接接头组织、抗拉强度和硬度的影响。结果表明:两种焊丝接头焊缝区均为典型的铸态枝晶组织,晶粒生长方向以弯曲形状垂直于焊接方向;与ER4043焊丝相比,BJ-380A焊丝接头的热影响区晶界中有更多的强化相析出;两种焊丝接头的抗拉强度均可达到母材的50%以上,拉伸断裂部位均位于热影响区;与BJ-380A焊丝相比,ER4043焊丝接头的强度和硬度更高,抗拉强度达到了母材的67.9%。

AC-TIG welding was performed on 2A12 aluminum alloy,the effects of ER4043 and BJ-380 A welding wires on microstructure,tensile strength and hardness of welded joints were discussed.The results show that the typical cast dendrite was obtained in the weld seam zone of the joints with the two types of welding wires,and the grain growth direction was perpendicular to the welding direction.Compared with ER4043 welding wire,more strengthening phases precipitated at grains boundaries at heat affected zone of the joint with BJ-380 A welding wire.The tensile strength of the both welded joints are over 50% of the base metal,and the fracture positions all were located on heat affected zone.Compared with BJ-380 A welding wire,the strength and hardness of the joint with ER4043 welding wire were higher,and its tensile strength up to 67.9% of the base metal.