5th International High Manganese Steel Conference - HMNS 2022

Medium Manganese steels represent an important family of steels that, if successfully implemented, can contribute toward enabling light weighting for increased fuel economy and extended electric vehicle range. Attractive tensile properties are obtained albeit highly sensitive to processing path. A review will be presented highlighting physical metallurgy fundamentals of medium manganese steels pertaining to microstructural evolution, processing and properties interrelationships. Austenite stabilization and its mechanical stability will be discussed. Annealing responses as influenced by time, temperature, prior microstructure and cementite dissolution will be discussed. Microstructural models assuming equilibrium phase fractions and solute enrichment of austenite, and diffusional calculations in one- and two-dimensions will be presented. In addition, processing routes alternate to intercritical annealing will be discussed in particular the recently proposed double soaking where intercritical annealing is followed by secondary soaking at higher temperature and quenching to partially replace the lean Mn ferrite present at the intercritical temperature into martensite following quenching to room temperature.