盐雾环境对超声冲击前后铝合金焊接接头力学性能的影响

Effect of salt spray environment on mechanical properties of aluminum welded joints treated with ultrasonic impact

对6005铝合金焊接接头进行超声冲击处理,对冲击前后焊接接头进行残余应力测试.结果表明,超声冲击后,6005铝合金焊缝及热影响区(HAZ)均变为残余压应力,应力分布较为均匀.对冲击前后试样进行盐雾腐蚀试验.超声冲击后的试样在腐蚀不同时间后,其腐蚀产物均少于未冲击试样,超声冲击后焊接接头硬度得到提高,焊缝及HAZ的硬化层深度分别为1.5 mm及2.1 mm,腐蚀14天后,硬化层能够保持在0.9 mm,可有效地保护基体.另外,腐蚀同样时间后,冲击后的焊接接头试样能够保持较好的综合力学性能.

The Al6005 welded joint was treated with ultrasonic impact and the residual stress of the treated and untreated specimens was measured. The results showed that uniform compressive stress distributed in the weld and heat-affected zone( HAZ) after the joint was treated with ultrasonic impact. The properties of welded joint were discussed after salt spray corrosion test. The results indicated that the treated joint produced less corrosion product after corrosion for different times. The hardness of the weld metal and HAZ increased after the joint was treated with ultrasonic impact. The thickness of hardened layer in the weld metal and HAZ was 1. 5 mm and 2. 1 mm,respectively. The thickness of hardened layer maintained at 0. 9 mm after corrosion for 14 days. Besides,the welded joint after treatment could have better mechanical properties than untreated joints.