In this study, we investigated the transformation kinetics of martensite → reverted austenite in 18 wt.% grade 300 Ni maraging steel. The kinetics was evaluated based on the in situ synchrotron x-ray diffraction data collected during isothermal heat treatment at 570°C. The onset of transformation martensite → reverted austenite was detected after ~ 5 min of aging. The austenite fraction increased as a function of annealing time and reached approximately 30 vol.% after 3 h of heat treatment. The electron backscatter diffraction technique revealed that reverted austenite is formed preferentially on both the martensitic lath boundaries and sub-grain boundaries inside the laths, in particular in those with high Taylor factor values. The reverted austenite maintains an orientation relationship with the prior austenite; however, variant selection can take place.

中文翻译：

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18 wt.% Ni 300 级马氏体时效钢中回复奥氏体的动力学：原位同步加速器 X 射线衍射和织构研究

在本研究中，我们研究了 18 wt.% 300 Ni 马氏体时效钢中马氏体→回复奥氏体的转变动力学。基于在 570°C 等温热处理期间收集的原位同步加速器 X 射线衍射数据评估动力学。在约 5 分钟时效后检测到转变马氏体→回复奥氏体的开始。奥氏体分数随着退火时间的增加而增加，热处理 3 小时后达到约 30 vol.%。电子背散射衍射技术表明，在马氏体板条边界和板条内部的亚晶界上优先形成回复奥氏体，特别是在具有高泰勒因子值的那些。回复奥氏体与原奥氏体保持取向关系；然而，