Abstract: Medium manganese (Mn) steels containing approximately 5 to 10 wt pct Mn show potential to meet the strength-ductility expectations of third generation advanced high strength steels. The attractive mechanical performance of these steels is closely related to significant metastable retained austenite levels. Thermodynamic models suggest that manganese partitioning during intercritical annealing can stabilize significant levels of austenite. In contrast, DICTRATM simulations have suggested that manganese mobility is too sluggish to enrich austenite on a practical time scale. However, many publications list experimental observations of elevated retained austenite levels after intercritical anneal times of an hour or less. The present paper explores changes in manganese mobility and solute carbon availability through DICTRATM simulations to help better predict retained austenite levels following intercritical annealing of medium Mn steels.
Authors: Josh J. Mueller and Emmanuel De Moor
Keywords: Dictra, Manganese Partitioning, Intercritical Annealing