In the current study, a metastable Fe-15Ni-8Mn-8Co-3Ti-1Si ferrous medium entropy alloy is subjected to powder high-pressure torsion (HPT) followed by annealing. The body-centered cubic microstructure obtained from the HPT method largely changes into a metastable face-centered cubic phase decorated by Ti-Si-rich precipitates during the isothermal post-annealing process. The optimum heat treatment results in materials with high ultimate tensile strength and total elongation of 748 MPa and 68.81%, respectively. The material is strengthened by the numerous grain boundaries created during recrystallization, which effectively impede dislocation movement and postpone the deformation-induced martensitic transformation (DIMT) to the applied strain of over 20%. High ductility and high strength are combined by employing the simultaneous effects of controlled DIMT, grain boundary engineering, and precipitate strengthening, resulting in multistep strain hardening of the corresponding specimen.

在当前的研究中，亚稳态 Fe-15Ni-8Mn-8Co-3Ti-1Si 铁基中熵合金经受粉末高压扭转 (HPT)，然后进行退火。通过 HPT 方法获得的体心立方微观结构在等温后退火过程中大量转变为由富 Ti-Si 沉淀物修饰的亚稳态面心立方相。最佳热处理导致材料具有高极限抗拉强度和总伸长率，分别为 748 MPa 和 68.81%。该材料通过再结晶过程中产生的大量晶界得到强化，这有效地阻止了位错运动并推迟了变形诱发马氏体相变（DIMT）到施加应变超过20%。