Abstract High-resolution characterization was used to understand the mechanisms controlling stress corrosion cracking (SCC) in Alloy 600 exposed to simulated PWR primary water conditions. Three potential active crack tips obtained from different types of grain boundaries were studied and compared. The results suggest that the dominant mechanism controlling SCC propagation is intergranular internal oxidation. The applied stress, pre-existent residual strain, the accumulation of defects around the crack tip, the formation of a Fe-Cr-depleted zone, and a porous intergranular oxide are acknowledged as necessary precursors to SCC. Based on the results obtained in this study, a model of SCC propagation is proposed.

中文翻译：

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通过高分辨率表征对 600 合金中的 SCC 进行力学研究

摘要 高分辨率表征用于了解暴露于模拟压水堆原水条件下的 600 合金中控制应力腐蚀开裂 (SCC) 的机制。研究和比较了从不同类型晶界获得的三种潜在的活性裂纹尖端。结果表明，控制 SCC 传播的主要机制是晶间内部氧化。施加的应力、预先存在的残余应变、裂纹尖端周围缺陷的积累、Fe-Cr 耗尽区的形成和多孔晶间氧化物被认为是 SCC 的必要前体。基于在本研究中获得的结果，提出了 SCC 传播模型。