316NG (00Cr17Ni12Mo2N) austenitic stainless steel was heat-treated at 600, 725 and 1000 °C to investigate the effects of heat treatment temperature and holding time on the fatigue crack growth behavior of this steel in deaerated water at 325 °C. It is found that fatigue crack growth rates in air at room temperature are decreased after the heat treatments, due to a reduced dislocation density. Corrosion fatigue crack growth rates in water at 325 °C are also decreased after the heat treatments at 600 and 1000 °C for 1 h, while the heat treatment at 725 °C leads to a moderate increase in the fatigue crack growth rate. The latter phenomenon results from a higher amount of CrNbN (Z-phase) precipitates formed in the steel after the annealing at 725 °C.

316NG (00Cr17Ni12Mo2N) 奥氏体不锈钢在 600、725 和 1000 °C 下进行热处理，以研究热处理温度和保温时间对该钢在 325 °C 脱气水中疲劳裂纹扩展行为的影响。发现热处理后室温空气中的疲劳裂纹扩展速率降低，这是由于位错密度降低。在 600 和 1000 °C 热处理 1 h 后，325 °C 水中腐蚀疲劳裂纹扩展速率也降低，而 725 °C 热处理导致疲劳裂纹扩展速率适度增加。后一种现象是由于在 725 °C 退火后钢中形成的 CrNbN（Z 相）析出物的数量较多。