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采用钨极惰性气体保护焊和金属惰性气体保护焊两种工艺对T6态AA6082合金管进行焊接,比较所得焊接接头的显微组织特性和力学性能。利用光学显微镜,拉伸测试和显微硬度测试研究焊接工艺的影响。结果表明,由于形成了细小的等轴晶且枝晶间距较小,TIG焊接接头的拉伸强度比MIG焊接接头的拉伸强度高,强度可提高25%。在焊接效率方面,TIG焊接可得到更可靠的强度,与MIG焊接相比,其强度可提高25%。两种焊接工艺焊缝区的硬度都大幅度降低,这是由于高温时材料发生了相变。MIG焊接样品的硬度较低,为1.08GPa。MIG焊接接头的热影响区比TIG焊接接头的稍大,这是由于单位长度的热输出更大。
The T6 AA6082 alloy tube was welded by Tungsten Inert Gas Welding and Metal Inert Gas Welding. The microstructure and mechanical properties of the welded joints were compared. Optical microscopy, tensile testing and microhardness testing were used to study the effects of the welding process. The results show that due to the formation of small equiaxed grains with small dendrite spacing, the tensile strength of TIG welded joints is higher than that of MIG welded joints, and the strength can be increased by 25%. TIG welding provides more reliable strength in terms of welding efficiency, up to 25% greater strength compared to MIG welding. Both welding process weld zone hardness is greatly reduced, this is due to the material phase transition occurred at high temperatures. The hardness of the MIG welding samples is lower at 1.08 GPa. The heat affected zone for MIG welded joints is slightly larger than for TIG welded joints due to the greater heat output per unit length.