A comparison of the mechanical and corrosion behavior of Fe49.5Mn25Cr15Ni10C0.5 medium-entropy alloy with its subsystems steels

Abstract

We systematically compared the mechanical and corrosion behavior of Fe49.5Mn25Cr15Ni10C0.5, a face-centered-cubic (FCC) medium-entropy alloy (MEA) with low-cost, with its subsystems steels (Fe74.5Cr15Ni10C0.5 and Fe74.5Mn25C0.5). It was found that all three alloys exhibited similar ductility at 298 K. The MEA has the highest yield strength and lowest ultimate tensile strength (UTS) at 298 K and 77 K, and the Fe74.5Cr15Ni10C0.5 alloy has the highest UTS, followed by Fe74.5Mn25C0.5 alloy. The MEA's ductility increase when temperatures decrease from 298 K to 77 K, in contrast to its subsystems steels, which had decreasing ductility. As a result, the MEA has the highest product of UTS and ductility (∼75 GPa·%) at 77 K. The twinning-induced plasticity was dominant in the MEA, while deformation-induced martensitic transformation from FCC to body-centered-cubic (BCC), and from FCC to hexagonal-close-packed (HCP) was dominant in Fe74.5Cr15Ni10C0.5, and Fe74.5Mn25C0.5 alloys, respectively. In addition, Fe74.5Cr15Ni10C0.5 alloy has the best corrosion resistance, followed by the MEA and Fe74.5Mn25C0.5.