Recovering the ductility of medium-Mn steel by restoring the original microstructure after forming

Abstract

To recover the reduced ductility of cold-working medium-Mn steels, a novel resetting process is suggested in this study. Through a simple heat treatment, the original microstructure of the steel is restored by the re-reversion of the Mn-enriched strain-induced martensite. The ductility of the reset is successfully recovered, and its strength is improved, relative to the steel prior to cold rolling. The present technique facilitates the use of a single steel sheet and a simple heat treatment process for an automotive component which originally comprised two different parts to compensate for the opposing attributes that it requires (e.g., having a high strength at the upper and high toughness at the bottom part of a center pillar).