Effects of Cr addition (0, 3, and 6 wt%) on Charpy impact properties of Fe-C-Mn-Cr-based steels were studied by conducting dynamic compression tests at room and cryogenic temperatures. At room temperature, deformation mechanisms of Charpy impacted specimens were observed as twinning induced plasticity (TWIP) without any transformation induced plasticity (TRIP) in all the steels. At cryogenic temperature, many twins were populated in the Cr-added steels, but, interestingly, fine ε-martensite was found in the 0Cr steel, satisfying the Shoji-Nishiyama (SN) orientation relationship, {$111$}_γ//{$0002$}_ε and < $101$ >_γ//< $11\overline{2}0$ >_ε. Even though the cryogenic-temperature staking fault energies (SFEs) of the three steel were situated in the TWIP regime, the martensitic transformation was induced by Mn- and Cr-segregated bands. In the 0Cr steel, SFEs of low-(Mn,Cr) bands lay between the TWIP and TRIP regimes which were sensitively affected by a small change of SFE. The dynamic compressive test results well showed the relation between segregation bands and the SFEs. Effects of Cr were known as not only increasing the SFE but also promoting the carbide precipitation. In order to identify the possibility of carbide formation, a precipitation kinetics simulation was conducted, and the predicted fractions of precipitated M₂₃C₆ were negligible, 0.4–1.1 × 10⁻⁵, even at the low cooling rate of 10 °C/s.

通过在室温和低温下进行动态压缩试验，研究了添加Cr（0、3和6 wt％）对Fe-C-Mn-Cr基钢的夏比冲击性能的影响。在室温下，在所有钢中均观察到夏比冲击试样的变形机理为孪生诱发塑性（TWIP），而没有任何转变诱发塑性（TRIP）。在低温下，添加Cr的钢中有许多孪晶，但有趣的是，在0Cr钢中发现了细小的ε马氏体，满足了Shoji-Nishiyama（S N）取向关系，{$111$} _γ // {$0002$} _ε和<$101$> _γ // <$11\overline{2}0$> _ε。即使这三种钢的低温温度失效断层能（SFE）处于TWIP形式，马氏体相变仍是由Mn和Cr偏析带引起的。在0Cr钢中，低（Mn，Cr）带的SFE位于TWIP和TRIP方案之间，这受SFE的微小变化敏感地影响。动态压缩试验结果很好地表明了分离带和SFE之间的关系。众所周知，Cr的作用不仅增加了SFE，而且还促进了碳化物的析出。为了确定形成碳化物的可能性，进行了沉淀动力学模拟，沉淀的M ₂₃ C ₆的预测分数可忽略不计，为0.4–1.1×10 ^-5，即使在10°C / s的低冷却速率下也是如此。