热处理温度对6082铝合金焊接接头性能的影响

Effect of heat treatment temperature on welding joint properties of 6082 aluminum alloy

为改善6082铝合金焊缝组织、性能,采用固溶+时效处理6082铝合金焊接接头。结果表明:6082铝合金的强化相为β-Mg_(2)Si相,焊缝强化相为Mg_(3)Al_(2),固溶+时效处理后焊缝区强度增加,熔合区无显著柱状晶体结构,热影响区受强化相β-Mg_(2)Si二次熔化影响,强度增强;焊接接头最低硬度在距离焊缝中心10 mm处,约为72HV;固溶+时效处理可提升焊接接头的拉伸性能;焊缝区断口为韧性断裂;时效温度为150、180、210℃时焊接接头抗拉强度较高,伸长率均值约为12%、13%、11%。

Solution+aging heat treatment was carried out to modify the microstructure and properties of welded joint of 6082 aluminum alloy.The results show that the phase that strengthens 6082 aluminum alloy is identified asβ-Mg_(2)Si phase,and thatfor weld metal is Mg_(3)Al_(2).After solution+aging heat treatment,the strength of weld metal is increased and no columnar grains canbe observed in the fusion zone,while the strengthening effect arising fromβ-Mg_(2)Si phase is reduced due to its remelting.Thelowest joint hardness value of the welded joint is about 72HV at the position 10 mm away from the weld center.Solution+agingheat treatment can greatly enhance the tensile property of weld.The fractography of weld metal exhibits a ductile fracture mode.When aged at 150℃,180℃and 210℃,the welded joints have high tensile strength and their elongation are about 12%,13%and 11%,respectively.