Effect of Tempering Temperature on the Microstructure and Mechanical Properties of Fe49.5Mn29.7Co9.9Cr9.9C1 HEA

Author of the article:LI Xiaolin, ZHAO Liyuan, LI Yating, HAO Xiaoxiao, WANG Haifeng

Author's Workplace：(State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China

Key Words：processing technology; high-entropy alloy; TWIP effect; TRIP effect; mechanical performance

Abstract：High-entropy alloys (HEAs) have been widely investigated due to their special properties, which are superior to those of traditional steels. However, the relatively low yield strength is one of the tough problems that need to be solved. In this paper, 1%C(atomic percentage) was added to an Fe50Mn30Co10Cr10 FCC high-entropy alloy to increase the yield strength of the alloy by precipitation strengthening. The result shows that the structure of the high-entropy alloy after forging, rolling and annealing is mainly composed of an FCC matrix and a small amount of the HCP phase. High-density nanoprecipitates are distributed in the FCC phase after annealing at 650, 800 and 900 ℃, which are identified as Cr23C6 by EDS, playing a pinning effect on the grain boundaries and thus increasing the yield strength of the alloy. In the process of tensile deformation of the high-entropy alloy, the content of the HCP phase and deformation twins increase with increasing tensile strain. In general, TRIP and TWIP effects can improve the work hardening rate of the alloy and ensure that the alloy has a high yield strength and good plasticity