摘要
Stress corrosion cracking （SCC） is degradation of mechanical properties under the combined action of stress and corrosive environment of the susceptible material. Out of eight series of aluminium alloys, 2xxx, 5xxx and 7xxx aluminium alloys are susceptible to SCC. Among them, 7xxx series aluminium alloys have specific application in aerospace, military and structural industries due to superior mechanical properties. In these high strength 7xxx aluminium alloys, SCC plays a vital factor of consideration, as these failures are catastrophic during the service. The understanding of SCC behaviour possesses critical challenge for this alloy. The main aim of this review paper is to understand the effect of constituent alloying elements on the response of microstructural variation in various heat-treated conditions on SCC behavior. Further, review was made for improving the SCC resistance using thermomechanical treatments and by surface modifications of 7xxx alloys. Apart from a brief review on SCC of 7xxx alloys, this paper presents the effect of stress and pre-strain, effect of constituent alloying elements in the alloy, and the effect of environments on SCC behaviour. In addition, the SCC behaviours of weldments, 7xxx metal matrix composites and also laser surface modifications were also reviewed.
应力腐蚀是材料在应力和腐蚀环境双重作用下使材料力学性能下降的行为。对于八种系列铝合金,2xxx、5xxx、7xxx铝合金对于应力腐蚀敏感。由于其优越的力学性能,7xxx铝合金广泛应用于航空、军事和结构工业。在这些7xxx铝合金中,应力腐蚀严重影响其力学性能,使其在服役过程中发生灾难性的失效。因此,研究该合金的应力腐蚀行为具有重要意义。本文综述了合金成分对合金在不同热处理条件下的显微组织演变,还综述了改善7xxx合金应力腐蚀性能的形变热处理和表面改性方法。此外,还综述了应力、预应变、合金成分和腐蚀环境对应力腐蚀行为的影响。还综述了焊缝、7xxx金属基复合材料和激光表面处理合金的应力腐蚀行为。
