The dynamic recrystallization microstructure characterizations of hot-rolled Fe50Mn30Co10Cr10 high-entropy alloy during different cooling rates

Abstract

This study investigated the dynamic recrystallization microstructure and recrystallization mechanisms of hot-rolled Fe 50 Mn 30 Co 10 Cr 10 high-entropy alloy (HEA) combining the microstructural characterization and the phase-field-crystal (PFC) simulations. For this purpose, hot rolling at 800°C with 50% thickness reduction was carried out after cold rolling. The samples were cooled using two different methods: air cooling and water quenching. Microstructural characterization was conducted using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Dynamic recrystallized grains were identified as grains with a grain orientation spread (GOS) value less than 2.2°. The results indicate that under different cooling rates, the occurrence of martensitic phase transformation was almost completely suppressed due to the small grain size. Furthermore, continuous dynamic recrystallization (CDRX) was the predominant DRX mechanism, while discontinuous dynamic recrystallization (DDRX) played a supplementary role in the dynamic recrystallization process. As the cooling rate increased, the proportion of CDRX also increased. The result of this work not only elaborate cooling have an effect on the dynamic recrystallization mechanism, but provide a conference for optimizing microstructure and mechanical properties through thermomechanical process.