Corrosion fatigue (CF) tests of Alloy 52/52 M weld metal from a safe-end welding joint of reactor pressure vessel were performed in B/Li high-temperature water. The CF cracks developed preferentially in 52 Mw with columnar grain orientation at a 45° - 75° angle to cyclic loading axis, rather than in 52b with columnar grain orientation parallel to loading axis. The environmental assisted fatigue effects were significant under lower strain amplitudes and the effect of strain rate on CF behavior was not significant. The CF cracking mechanism involved with welding columnar grain orientation is discussed.

中文翻译：

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焊接柱状晶粒取向和应变速率对52 / 52M合金焊缝金属在高温水中腐蚀疲劳行为的影响

在B / Li高温水中，对反应堆压力容器安全端焊接处的52/52 M合金焊接金属进行了腐蚀疲劳（CF）测试。CF裂纹优先出现在52 Mw时，其柱状晶粒取向与循环载荷轴成45°-75°角，而不是52b时，其柱状晶粒取向平行于载荷轴。在较低的应变幅度下，环境辅助疲劳效应显着，应变速率对CF行为的影响不显着。讨论了与焊接柱状晶粒取向有关的CF开裂机理。