Abstract Correlation of microstructure and stress corrosion cracking (SCC) initiation behaviour of the fusion boundary (FB) region in a SA508 Cl. 3-Alloy 52M weld joint in primary pressurized water reactor environment was investigated. Cr-depletion at the grain boundary and strength mismatch in the FB region are the two causes for SCC initiation in the FB region. The partially mixed zone between the dilution zone (DZ) of Alloy 52M and SA508 Cl. 3 has a retardation effect on SCC initiation. This is attributed to the decrease of strength mismatch and the alleviation of strain concentration adjacent to the grain boundary in DZ.

中文翻译：

---

SA508 Cl 熔合边界区域的显微组织与应力腐蚀开裂行为的相关性。一次压水堆环境中的 3 合金 52M 异种焊接接头

摘要 SA508 Cl 熔合边界 (FB) 区域的微观结构和应力腐蚀开裂 (SCC) 引发行为的相关性。研究了一次压水堆环境中的 3 合金 52M 焊接接头。晶界处的 Cr 耗尽和 FB 区的强度不匹配是 FB 区 SCC 萌生的两个原因。合金 52M 和 SA508 Cl 的稀释区 (DZ) 之间的部分混合区。3 对 SCC 的引发具有延迟作用。这归因于强度失配的减少和 DZ 中邻近晶界的应变浓度的减轻。