In the present study, thermomechanical processes at ferrite + austenite two-phase temperatures were applied to a 5Mn-0.1C-2Si (wt%) medium-manganese steel having a martensite starting microstructure to investigate the effect of high-temperature processing on microstructure evolution and mechanical properties. Microstructural observations clarified that not only hot compression but also isothermal holding after the hot compression greatly increased the amount of retained austenite at room temperature compared with the statically annealed specimen. The specimens thermomechanically-processed at various temperatures showed complicated changes in mechanical properties at room temperature. Even when the specimens included similar amounts of retained austenite, their mechanical responses varied widely, which was considered to be attributed to the chemical compositions of retained austenite controlled by partitioning of alloying elements during processing in two-phase temperatures.

在本研究中，将铁素体+奥氏体两相温度下的热机械过程应用于具有马氏体起始显微组织的5Mn-0.1C-2Si（wt％）中锰钢，以研究高温处理对显微组织演变的影响和机械性能。显微组织观察表明，与静态退火试样相比，不仅在室温下热压缩，而且在热压缩后的等温保持都大大增加了奥氏体的保留量。在各种温度下热机械加工的样品在室温下显示出复杂的机械性能变化。即使标本中包含相似量的残留奥氏体，其机械响应也会有很大差异，