2219铝合金母材及搅拌摩擦焊接头应力腐蚀敏感性

Stress corrosion cracking susceptibility of 2219 aluminium alloy parent metal and its friction stir weldment

摘要: 利用慢应变速率拉伸试验,研究2219铝合金母材及搅拌摩擦焊接头在不同腐蚀介质环境中的应力腐蚀行为.运用性能损失率指标和应力腐蚀指数评价材料的应力腐蚀敏感性.结果表明,应变速率为10^-6 s^-1时,2219铝合金母材和FSW接头在3.5%Na Cl介质环境中SCC敏感性小,断口由韧窝塑性区和腐蚀区组成;在剥蚀介质环境中,母材和FSW接头SCC敏感性大,断口呈冰糖状,有较深的腐蚀坑和二次裂纹,为沿晶脆性断裂.FSW接头SCC敏感性较母材大.

Abstract: The stress corrosion cracking(SCC) suspectbility of 2219 aluminium alloy and its friction stir weldment in different environmenthas been tested using slow strain rate testing(SSRT). The performance loss rate indicator and stress corrosion cracking index were used to evaluate SCC susceptibility.The SSRT test in 3.5% NaCl solution at a strain rate of 10^-6 s^-1 has shown that the SCC susceptibility of parent metal and weldment were small and the fracture was composed of ductile dimples and corrosion zones. However, the parent metal and the weldment were susceptible to SCC exhibiting intergranular fracture in exfoliation corrosion(EXCO) solution at the same strain rate. The friction stir weldment was more susceptible to SCC than parent metal.