Effect of warm rolling on microstructure and mechanical properties of Fe₅₀Mn₃₀Co₁₀Cr₁₀ high-entropy alloy

In this study, specific warm rolling was carried out to process the Fe₅₀Mn₃₀Co₁₀Cr₁₀ high-entropy alloy. The aim was to investigate the effect of warm rolling temperature on the microstructure and mechanical properties. The results indicated that serious transverse cracks appeared in the 25 °C rolled sheet with reduction of 60%, which was significantly improved through 100–300 °C warm rolling. In addition, the increase of rolling temperature promoted dislocation slip and inhibited martensitic transformation and twinning deformation. A single face centered cubic (FCC) matrix with abundant dislocations and stacking faults was developed in the 300 °C rolled microstructure. Meanwhile, the deformation stored energy gradually increased, and the copper-type deformation texture was gradually enhanced. After annealing, the recrystallized microstructure of 25–200 °C rolled sheets was composed of FCC and a small amount of HCP phase. However, the hexagonal close packed (HCP) content in the annealed sheet rolled at 300 °C was as high as 20%–23% after annealing for 2–4 min and decreased to 4.5% after annealing for 8 min. All recrystallized microstructure contained a large number of annealing twins, and the average grain size increased with the increase of rolling temperature. Moreover, the mechanical properties of the annealed sheet were significantly improved after warm rolling.