A review of the processing, microstructure and property relationships in medium Mn steels

ABSTRACT

Medium Mn steels are an emerging class of 3rd generation advanced high-strength steels. These steels have received significant attention due to their high strengths, large ductilities and also lower cost compared to their predecessor high Mn Twinning Induced Plasticity (TWIP) steels. Additionally, medium Mn steels have been found to exhibit TWIP and/or Transformation Induced Plasticity (TRIP) effects which can be harnessed to give a high strain hardening rate. Many thermomechanical processing concepts in the literature have been developed, producing multiple microstructure types with differentmechanical properties. The present review therefore aims to summarise the current knowledge of medium Mn steel alloy design especially on the processing, microstructure and property relationships in medium Mn steels. It complements the review of Sun et al. [Physical metallurgy of medium-Mn advanced high-strength steels, Int Mater Rev. 2023.], written independently and in parallel, which focusses more on the phase interfaces and thermodynamics.

KEYWORDS:

• Medium Mn steel
• advanced high strength steel
• TWIP+TRIP
• thermomechanical processing
• microstructure
• thermo-calc
• microstructure
• mechanical properties

Acknowledgments

The authors would like to express their deep gratitude to Professors D Ponge, D Krizan, E De Moor and JR McDermid for insightful discussions and guidance. TWJK would like to acknowledge the provision of a studentship by A*STAR, Singapore.

Disclosure statement

No potential conflict of interest was reported by the author(s).