Near‐atomic scale characterization of Mn‐gradient in reverted austenite in hot‐rolled medium‐Mn steels

In the present work, Fe-5Mn-2Al-0.1C (wt.%) and micro-alloyed Fe-5Mn-2Al-0.1C-0.1Nb-0.2V medium Mn steels were processed by a novel flash-austenite-reverse-transformation (ART) annealing. The core-shell Mn-gradient in austenite was observed compositionally characterized at near-atomic scale using atom probe tomography (APT). Compared with conventional ART annealing, flash-ART process doubled fraction both materials, based on electron backscattering diffraction (EBSD) measurement. rapid reversion annealed MMnS attributed to negligible partitioning local equilibrium (NPLE) controlled kinetics flash temperature. formation of due different growth interface mobilities. Microalloying elements found form nano-carbides, which leads decelerating because depleted carbon content initial martensitic microstructure, retarding according pinning effect. This article is protected copyright. All rights reserved.