The austenite stability and the mechanical properties in a typical medium Mn grade steel, i.e., 5Mn steel, were investigated under a wide range of strain rates through the combination of experimental and theoretical methodologies. The obtained results indicate that austenite is more stable at a high strain rate, which is due to the suppression of the austenite to martensite transformation. This suppression is attributed to the increased stacking fault energy and the high deformation energy barrier. Moreover, the suppression of martensitic transformation also leads to the decrease in the ultimate tensile strength and the uniform elongation. Owing to the increase in an adiabatic heating temperature, an increase in the uniform elongation is acquired at a high strain rate. The obtained fundamental study results shed light on a wide application of the medium Mn steel under different strain rate conditions.

通过实验和理论方法的结合，研究了典型的中等Mn级钢（即5Mn钢）在各种应变速率下的奥氏体稳定性和力学性能。所得结果表明，奥氏体在高应变速率下更稳定，这是由于抑制了奥氏体向马氏体的转变。这种抑制归因于增加的堆垛层错能和高变形能垒。此外，马氏体相变的抑制还导致极限抗拉强度和均匀伸长率的降低。由于绝热加热温度的增加，以高应变率获得了均匀伸长率的增加。