摘要
采用表面腐蚀、慢应变速率拉伸(SSRT)实验研究预拉伸变形对Al-Cu-Mg合金腐蚀性能的影响。利用扫描电镜观察分析Al-Cu-Mg合金断口形貌及结构。结果表明,预拉伸变形可显著提高合金位错密度,为H原子的扩散提供更多的通道,因此,在相同腐蚀时间下,3.5%Na Cl溶液中T8态Al-Cu-Mg合金的腐蚀速率高于T6态。此外,预拉伸变形可显著增加S相弥散度,使得S相两侧的无沉淀析出带变窄,有效降低了晶界和晶内的电位差,从而降低晶界沉淀相的溶解速度,因此,在同一热处理状态下,Al-Cu-Mg合金在饱和H2S溶液中的应力腐蚀开裂敏感性高于干燥空气中的腐蚀开裂敏感性。同一应变速率下,T8态Al-Cu-Mg合金具有比T6态更好的抗应力腐蚀性能,表明预拉伸变形处理可显著提高合金的抗应力腐蚀性能。
The corrosion behavior of Al-Cu-Mg alloy was investigated by a combination of the surface corrosion and slow strain rate tension（SSRT）. The fracture surface of each investigated condition was characterized by scanning electron microscopy（SEM）. The results show that, by pre-stretching, the dislocation density can be improved with providing more channels for the diffusion of H atoms, the corrosion rate of the Al-Cu-Mg alloy in T8 temper is higher than that of T6 temper in 3.5%Na Cl solution for the same period. The dispersity of S phase was dramatically increased by pre-stretching with the no-precipitation band narrows on both sides of S phase, reducing the potential difference between the grain boundary and grain interior. Al-Cu-Mg alloy is more susceptible to Stress Corrosion Crack（SCC） in saturated H2S solution than in dry air. Compared to T6 treatment, pre-stretching is beneficial to enhance the SCC resistance of Al-Cu-Mg alloy at the same strain rate.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2015年第1期72-77,共6页
Materials Science and Engineering of Powder Metallurgy
基金
广东省教育部产学研结合项目(2012B091100475)
