Abstract The corrosion behaviour of AA2198-T851 alloy has been investigated using a combination of immersion tests and different microscopy techniques. Results showed that severe localized corrosion initiated within 1 h of corrosion immersion test in 0.01 mol L −1 NaCl solution. The corrosion mechanism in this alloy is intragranular and it propagates crystallographically. The propagation occurs through grain orientation dependent bands and it can be likened to the movement of dislocation through slip planes. Corrosion rings around stable pits result from pH variations. Secondary pits form around primary pits within corrosion rings and are preceded by hydrogen evolution.

中文翻译：

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AA2198-T851合金显微组织及其与局部腐蚀行为的相关性

摘要 AA2198-T851 合金的腐蚀行为已使用浸泡试验和不同的显微镜技术相结合进行了研究。结果表明，在 0.01 mol L -1 NaCl 溶液中腐蚀浸渍试验 1 小时内开始了严重的局部腐蚀。这种合金的腐蚀机制是晶内的，它在晶体学上传播。传播通过晶粒取向相关带发生，它可以比作位错通过滑移面的运动。稳定坑周围的腐蚀环是由 pH 值变化引起的。在腐蚀环内的主要凹坑周围形成二次凹坑，并且在析氢之前。