Abstract Surface, stagnant grain boundary (GB), and crack tip oxidation of Alloy 600 were studied. The mirror-finished surface oxide has a duplex structure and the formation mechanisms of each layer are discussed. A more compact oxide film is observed on the cold-worked surface, while the nano-GBs are preferentially oxidized. The crack tip oxidation rate is around four orders of magnitude faster than that of the stagnant GB, and their oxidation mechanisms are believed to be the same. Diffusion-induced grain boundary migration (DIGM) is observed around the crack and oxidized GB tips. The role of Ni expulsion on the DIGM is discussed.

中文翻译：

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通过高分辨率表征研究 600 合金的表面和裂纹尖端氧化

摘要 研究了 600 合金的表面、停滞晶界 (GB) 和裂纹尖端氧化。镜面抛光的表面氧化物具有双相结构，并讨论了每一层的形成机制。在冷加工表面上观察到更致密的氧化膜，而纳米 GBs 被优先氧化。裂纹尖端的氧化速率比停滞的 GB 快四个数量级左右，并且它们的氧化机制被认为是相同的。在裂纹和氧化的 GB 尖端周围观察到扩散诱导的晶界迁移 (DIGM)。讨论了镍排出对 DIGM 的作用。