Nickel-free high-manganese austenitic Fe–24.4Mn–4.04Al–0.057C steel was produced by smelting, and the homogenized forged billet was hot-rolled. The plastic deformation mechanism was investigated through tensile testing of the hot-rolled sample. Different characterization techniques such as scanning electron microscopy, transmission electron microscopy, electron backscattered diffraction, and X-ray diffraction were used to analyze the microstructural evolution of steel under different strain levels. The steel had a single austenite phase, which was stable during deformation. After hot rolling, annealing twins were observed in the microstructure of the steel. The steel showed an excellent combination of mechanical properties, like a tensile strength of 527 MPa, impact energy of 203 J at − 196 °C, and an elongation of 67% till fracture. At the initial deformation stage, the dislocations were generated within the austenite grains, entangled and accumulated at the grain boundaries and annealing twin boundaries. Annealing twins participated in plastic deformation and hindered the dislocation movement. As the deformation progressed, the dislocation slip was hindered and produced stress concentration, and the stacking faults evolved into mechanical twins, which released the stress concentration and delayed the necking.

通过冶炼生产无镍高锰奥氏体Fe–24.4Mn–4.04Al–0.057C钢，然后对均质的锻造方坯进行热轧。通过热轧样品的拉伸试验研究了塑性变形机理。使用不同的表征技术，例如扫描电子显微镜，透射电子显微镜，电子背散射衍射和X射线衍射，来分析钢在不同应变水平下的组织演变。该钢只有一个奥氏体相，在变形过程中是稳定的。热轧后，在钢的显微组织中观察到孪晶退火。这种钢表现出优异的机械性能，例如抗张强度为527 MPa，在-196°C时的冲击能为203 J，断裂时的伸长率为67％。在初始变形阶段，位错在奥氏体晶粒内产生，纠缠并累积在晶界并退火双晶界。退火孪晶参与塑性变形并阻碍位错运动。随着变形的进行，位错滑移受到阻碍并产生应力集中，并且堆垛层错演变成机械孪晶，从而释放了应力集中并延迟了颈缩。