Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea.
Joining and Welding Research Institute, Osaka University, 11-1, Osaka, 567-0047, Japan.
Sci Rep. 2017 Jun 15;7(1):3573. doi: 10.1038/s41598-017-03862-y.
Recently, Fe-Mn twinning-induced plasticity steels with an austenite phase have been the course of great interest due to their excellent combination of tensile strength and ductility, which carbon steels have never been able to attain. Nevertheless, twinning-induced plasticity steels also exhibit a trade-off between strength and ductility, a longstanding dilemma for physical metallurgists, when fabricated based on the two alloy design parameters of stacking fault energy and grain size. Therefore, we investigated the tensile properties of three Fe-Mn austenitic steels with similar stacking fault energy and grain size, but different carbon concentrations. Surprisingly, when carbon concentration increased, both strength and ductility significantly improved. This indicates that the addition of carbon resulted in a proportionality between strength and ductility, instead of a trade-off between those characteristics. This new design parameter, C concentration, should be considered as a design parameter to endow Fe-Mn twinning-induced plasticity steel with a better combination of strength and ductility.
最近，由于具有奥氏体相的铁-锰孪晶诱发塑性钢具有优异的拉伸强度和延展性，这是碳钢从未达到的，因此引起了极大的关注。然而，孪晶诱发塑性钢在基于两个合金设计参数——堆垛层错能和晶粒尺寸——制造时，也表现出强度和延展性之间的权衡，这是物理冶金学家长期以来的难题。因此，我们研究了具有相似堆垛层错能和晶粒尺寸但碳浓度不同的三种 Fe-Mn 奥氏体钢的拉伸性能。令人惊讶的是，当碳浓度增加时，强度和延展性都显著提高。这表明，碳的添加导致了强度和延展性之间的比例关系，而不是这些特性之间的权衡。这个新的设计参数，碳浓度，应该被视为赋予 Fe-Mn 孪晶诱发塑性钢更好的强度和延展性组合的设计参数。
