焊后热处理对6082-T6铝合金焊接接头组织和性能的影响

对6082-T6铝合金焊接接头进行固溶+时效和时效两种热处理，研究不同热处理制度对其组织和性能的影响。实验结果表明：未处理的6082-T6焊接接头抗拉强度为225 MPa，断裂位置位于热影响区，接头硬度最低值均在热影响区；经时效处理后的6082-T6焊接接头处强化相分布更加均匀，焊缝区组织无明显变化，熔合区和热影响区组织轻微细化，抗拉强度为264 MPa，断裂位置仍在热影响区，接头硬度最低值均在热影响区；经固溶+时效处理后的6082-T6焊接接头处重新析出细小的强化相，熔合区和热影响区组织有明显的细化，抗拉强度提高到302 MPa，断裂发生在焊缝区，硬度值明显高于未处理6082-T6焊接接头的，硬度最低值位于焊缝区。

Effect of Post-weld Heat Treatment on the Microstructure and Properties of 6082-T6 Aluminum Alloy Welded Joints

6082-T6 aluminum alloy welded joints were subjected to two kind of heat treatments, which were aging and solid solution + aging, respectively. The effects of different heat treatment systems on the microstructure and properties were studied. The experimental results show that the tensile strength of the untreated 6082-T6 welded joint is 225 MPa, and both the fracture position and the minimum hardness are located in the heat affected zone. After aging treatment, the distribution of strengthening phase in 6082-T6 welded joint is more uniform, obvious change of the microstructure does not appear in the weld zone, the microstructures in fusion zone and heat affected zone are slightly refined, the tensile strength is 264 MPa, and the fracture position and the minimum hardness are still located in heat affected zone. After solid solution + aging treatment, fine strengthening phase precipitates again in the welded joint of 6082-T6, the microstructures in fusion zone and heat affected zone are refined obviously, the tensile strength is increased to 302 MPa, the fracture position is in the weld zone, the hardness value is significantly higher than that of the untreated 6082-T6 welded joint, and the lowest hardness value is located in the weld zone.