焊后热处理对6061-T4铝合金焊接接头组织和性能的影响

Effect of Post Weld Heat Treatment on Microstructure and Mechanical Properties of 6061-T4 Aluminum Alloy Welded Joint

以6061-T4铝合金作为研究对象,对焊后的6061-T4铝合金焊接接头部分采取不同的热处理制度,通过硬度测试、光学显微组织分析及扫描电镜分析等手段,研究不同的热处理制度对6061-T4铝合金焊接接头组织和性能的影响。结果表明:适当延长6061-T4铝合金焊接接头的焊后人工时效时间可以改善其焊接后的力学性能。T4焊后重新固溶、时效的综合力学性能低于T4焊后时效处理,但焊接接头组织不均匀性和强化相分布得到改善,热影响区软化消失,焊接接头强度得到恢复。

Taking the 6061-T4 aluminum alloy as the objective, the effects of post weld heat treatment on microstructure and mechanical properties of welded joint were studied by using optical microscopy（OM）, scanning electron microscopy（SEM） and hardness test. The results show that the mechanical properties of 6061-T4 aluminum alloy welded joint can be improved by extending aging time appropriately. The mechanical properties of welded joints of 6061-T4 aluminum ahoy with solid solution and ag- ing treatment are lower than those only with aging treatment, however, the uniformity of microstructure and the distribution of strengthen phases are improved, the softening effect of heat affected zone disappeared and the strength of welded joint were recovered.