5th International High Manganese Steel Conference - HMNS 2022

Here, we suggest a new thermomechanical process, which is referred to as resetting process, to recover the reduced ductility in cold-worked medium-Mn steel. The objective of the present study is motivated by the fact that one automotive component sometimes requires the two different parts for compensation of opposing attributes. For example, the upper part of center pillar needs a high strength for the intrusion resistance, while the bottom part of it needs a high ductility to absorb the impact energy. To make such automotive components, tailor-welded blank and hot stamping processes have been widely used in industry. However, these processes could deteriorate the productivity, and lead to mechanical degradation at the welded zone. In the present study, through a simple heat treatment after cold forming, we realize that the original microstructure before deformation is restored by re-reversion of Mn-enriched martensitic phase, resulting in a recovered ductility. Namely, the present technique facilitates the use of single sheet steel for an automotive component comprised of two different parts to compensate opposing attributes.