Recent advances in medium-manganese steel: a review of key findings, challenges, and future perspectives

This review paper aims to provide an overview of the advancements achieved with medium-manganese steel (MMnS) for its application in the automobile industry. The review work will cover various aspects, including chemical composition design, the correlation between structure and properties, deformation mechanism, effect of strain rate, electrochemical behavior, wear, and weldability response. We classify MMnS as third-generation advanced high-strength steels. The automotive industry widely utilizes these steels due to their superior properties and performance. Various factors, including the phase composition and distribution within the microstructure, the volume fraction, size, and morphology of phase constituents, and the stability of metastable constituents, influence the tensile properties of MMnS. High transformation-induced plasticity effect and dislocation density increase strength and ductility at low strain rates. Dynamic impact properties of MMnS depend on ductile-to-brittle transition temperature, chemical composition, and austenite mechanical stability. Due to low current density, charge transfer resistance, corrosion rate, and austenite manganese concentration, higher-temperature annealing resists corrosion better. MMnS can be welded using friction stir welding to retain their mechanical properties and prevent martensitic transformation. The present article provides an insight into the recent works, new sector applications, industrial-scale feasibility, long-term phase stability, future scope, and challenges of MMnS.