7xxx系铝合金应力腐蚀的控制

Control on Stress Corrosion of 7xxx Aluminum Alloys

综述了7xxx系铝合金的应力腐蚀开裂机理(Stress corrosion cracking)与影响因素。应力腐蚀开裂机理主要有阳极溶解理论、氢致理论与"相变-Mg-H"理论。适当的固溶工艺与时效工艺可以提高铝合金的抗应力腐蚀性能;铝合金的应力腐蚀开裂敏感性随水蒸气中氧含量的增加而提高,含有Cl-、Br-和I-的水溶液会加快铝合金的应力腐蚀开裂的裂纹扩展速率。

The stress corrosion cracking mechanisms and influence factors of 7xxx series aluminum alloys are summarized. The mechanisms include anodic dissolution theory, hydrogen induced theory and ＂phase change-Mg-H＂ theory. Appropriate solution process and aging treatment can improve the performance of aluminum alloys＇ anti-stress corrosion; with the increase of oxygen content in the water steam, the sensitivity of aluminum alloys to stress corro- sion cracking increases. The rate of expanding of stress corrosion cracking will be accelerated when aluminum alloys are serviced in the water steam including Cl-, Br- and I-.