7A52铝合金焊接件应力腐蚀性能评价  

SCC Evaluation on Welding Samples of 7A52 Aluminum Alloy

作　　者：张晓云[1] 梅克力 熊文华 郭孟秋[1] 高健[1] 

机构地区：[1]北京航空材料研究院,北京100095 [2]重庆长安汽车责任有限公司,重庆400023

出　　处：《材料工程》2013年第10期86-92,97,共8页Journal of Materials Engineering

摘　　要：应用慢应变速率拉伸应力腐蚀实验方法和恒载荷拉伸应力腐蚀实验方法评价了7A52铝合金焊接试样的应力腐蚀(SCC)敏感性,并对断口微观形貌进行了分析。结果表明:使用5A56焊丝,采用金属焊条惰性气体焊接(MIG)工艺双面焊制成7A52焊接件应力腐蚀敏感性比较低,具有较好的抗应力腐蚀开裂性能;但当使用环境温度较高、施加应力大于90%σp0.2时,也有可能发生应力腐蚀开裂。断口微观分析表明焊接部位普遍存在气孔;高温或高应力下产生SCC开裂的断口存在明显的二次裂纹,并且随着应力水平的增加,二次裂纹增大。The susceptibility of welding samples of 7A52 aluminum alloy to stress corrosion cracking （SCC） was evaluated using the slow strain rate test （SSRT） and direct tension stress corrosion test. The microstructure was also investigated after the SCC test. The results show low susceptibility to SCC of welding joint by 5A56 welding wire, metal inertia gas （MIG） procedure welded from both side. It is also possible SCC at high level stress and high temperature. The SEM indicated there are pores in welding part. High SCC sensitivity was expressed in high temperature or stress level. Sec- ondary cracking existed on the fracture surface, large size secondary cracking increases obviously with the higher of stress level.

关 键 词：应力腐蚀开裂 焊接 铝合金 

分 类 号：TG172.9[金属学及工艺—金属表面处理]