Abstract Recurring step straining was developed to investigate the environmentally assisted cracking (EAC) initiation of a Ni-30Cr-10Fe alloy (Alloy 690) in simulated pressurized water reactor (PWR) primary water. Thanks to this technique, the roles of corrosion and straining in the EAC initiation of Alloy 690 was decoupled and typical microstructures in stress corrosion cracking, i.e. diffusion induced grain boundary migration and oxidation into the migration zone, were reproduced. Digital image correlation using indigenous surface oxide particles as markers was successfully incorporated into this technique for high-resolution in-plane strain measurement. The preliminary results show that intergranular crack initiation is correlated with the high local strain in both adjacent grains, indicating that slip transfer across the grain boundary promotes crack initiation. Recurring step straining is desirable for the mechanistic study of EAC as it makes the separate roles of chemical and mechanical processes adjustable and traceable.

中文翻译：

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Ni-30Cr-10Fe合金在模拟压水反应堆一次水中引发环境辅助开裂机理研究的新试验技术

摘要 为了研究 Ni-30Cr-10Fe 合金（合金 690）在模拟压水反应堆 (PWR) 一次水中的环境辅助开裂 (EAC) 引发，开发了重复步进应变。由于这种技术，腐蚀和应变在合金 690 的 EAC 引发中的作用被解耦，并且重现了应力腐蚀开裂中的典型微观结构，即扩散引起的晶界迁移和氧化进入迁移区。使用本地表面氧化物颗粒作为标记的数字图像相关性成功地结合到该技术中，用于高分辨率面内应变测量。初步结果表明，晶间裂纹的萌生与两个相邻晶粒的高局部应变有关，表明滑移穿过晶界促进裂纹萌生。EAC 的机械研究需要重复的步骤应变，因为它使化学和机械过程的单独作用可调整和可追溯。