6082铝合金搅拌摩擦焊缝的应力腐蚀行为

The stress corrosion behavior of 6082 aluminum alloy joint by friction stir welding

摘要:

通过慢应变速率拉伸试验，借助电镜扫描、动电位扫描及光学显微分析等手段，对铝合金搅拌摩擦焊缝及母材的耐应力腐蚀性能及微观组织进行了对比研究．结果表明：当慢应变速率为3．3×10-6s-1时，在浓度为3．5，的NaCl溶液中焊缝的应力腐蚀敏感性略高于母材；无论在空气还是在腐蚀液中，二者均呈现相似的韧性断裂形貌，表现出良好的抗应力腐蚀性能；焊缝的自腐蚀电位较之母材略有降低，且焊缝热影响区晶粒明显粗化，预示着焊缝在抗应力腐蚀方面性能比母材差．

Abstract:

The stress corrosion cracking properties and microstructure of 6082 aluminum alloy weld joint and base metal are investigated by slow strain rate tensile test ,electron microscope scanning ,optical mi-croscopic structure inspection and dynamic potential scanning ,etc .It was found that the base material showed a slightly higher SCC sensitivity than that of the welded joint of 6082 aluminum alloy in NaCl solu-tion with a concentration of 3 .5， at the slow strain rate of 3 .3 × 10-6 s-1 ;both the weld joint and the base material demostrated excellent stress corrosion resistance with similar ductile fracture morphology either in air or NaCl solution with a concentration of 3 .5， ;the self-corrosion potential of weld joint is a little lower than that of base material and the grains of weld joint obviously grow coarse in heat affected zone by com-parison with base material ,indicating the base material is better than the weld joint in SCC resistance .