The environment assisted cracking (EAC) behavior, including stress corrosion cracking (SCC) and corrosion fatigue (CF), of a low carbon 308 L stainless steel weld metal was evaluated in high temperature water. The effects of thermal aging (400 °C for 10,000 h) on the crack growth rate (CGR) are discussed. Experimental results reveal an environmental acceleration effect on CGRs with decreasing loading frequency, and the environmental enhancement factor reached a value of 50 when the frequency was decreased to 0.00001 Hz. The 308 L weld metal showed excellent SCC resistance regardless of the thermal aging or water chemistry, which is related to the low carbon content and well-controlled duplex microstructure. After thermal aging, the ferrite/austenite (γ/δ) phase boundaries show negligible sensitization, consistent with the low carbon concentration. No preference of the γ/δ crack path and no elevated EAC either with thermal aging or in oxidizing water was attributed to the no sensitization of the γ/δ boundaries before and after thermal aging.

在高温水中评估了低碳 308 L 不锈钢焊缝金属的环境辅助开裂 (EAC) 行为，包括应力腐蚀开裂 (SCC) 和腐蚀疲劳 (CF)。讨论了热老化（400 °C 持续 10,000 小时）对裂纹扩展速率 (CGR) 的影响。实验结果表明，随着加载频率的降低，环境加速对 CGR 有影响，当频率降低到 0.00001 Hz 时，环境增强因子达到了 50 的值。无论是热老化还是水化学，308 L 焊缝金属都表现出优异的 SCC 抗性，这与低碳含量和良好控制的双相微观结构有关。热时效后，铁素体/奥氏体 (γ/δ) 相界显示出可忽略不计的敏化，与低碳浓度一致。