The low-cycle fatigue (LCF) behavior of Fe–0.1C–5Mn medium manganese transformation-induced plasticity steel in its as-received (AR: 0% pre-strained) and 10%, 15%, and 20% pre-strained conditions was analyzed. Microstructural evolution during pre-straining and cyclic loading was characterized by X-ray diffraction, electron backscatter diffraction, and transmission electron microscopy. The LCF properties of the steel were observed to gradually improve as pre-straining increased. Moreover, during pre-straining, the blocky austenite grains were successively split into thin film-like austenite by fresh lath martensite. It refined the microstructure, delayed fatigue crack initiation, prevented crack growth, and resulted in notable improvements in the LCF performance.

Fe-0.1C-5Mn 中锰相变诱发塑性钢在​​其原始状态（AR：0% 预应变）和 10%、15% 和 20% 预应变时的低周疲劳 (LCF) 行为条件进行了分析。预应变和循环加载过程中的微观结构演变通过 X 射线衍射、电子背散射衍射和透射电子显微镜进行了表征。观察到钢的 LCF 性能随着预应变的增加而逐渐提高。此外，在预应变过程中，块状奥氏体晶粒相继被新鲜板条马氏体分裂成薄膜状奥氏体。它改善了微观结构，延迟了疲劳裂纹的萌生，防止了裂纹扩展，并显着改善了 LCF 性能。