Processing Variants in Medium-Mn Steels
5. Summary
Some atypical and potentially novel processing scenarios for medium-Mn steels were discussed, including (1) use of medium-Mn steels for hot-stamping, (2) “double soaked” medium-Mn steels for cold-formable applications at strength levels greater than are commonly achieved via intercritical annealing, and (3) medium-Mn steels processed by quenching and partitioning. For all processing histories emphasized here, increased strength levels are achieved by employing appreciable martensite fractions, with ductility enhancements resulting from TRIP behavior associated with Mn-enriched austenite. An apparent influence of Mn on austenite evolution during partitioning was also highlighted.
The austenite stabilizing effects of Mn facilitate a variety of industrially important processing pathways, including room-temperature quenching temperatures. These processing opportunities and associated mechanisms of microstructure evolution remain fruitful areas for further research.
Author Contributions: Authors contributed to conceptualization (J.S., E.D.M., D.M., R.R., G.T., A.G.), methodology (J.S., E.D.M., D.M., R.R., G.T., A.G.), investigation (E.D.M., R.R., G.T., A.G.), formal analysis (J.S., E.D.M., D.M., R.R., G.T., A.G.), data curation (E.D.M., R.R., G.T., A.G.), original draft preparation (J.S.), review and editing (J.S., E.D.M., D.M., R.R., G.T., A.G.), supervision (J.S., E.D.M., D.M., R.R.), project administration (J.S., D.M.), and funding acquisition (J.S., E.D.M., D.M.).
Funding:The sponsors of the Advanced Steel Processing and Products Research Center (ASPPRC) at the Colorado School of Mines are gratefully acknowledged.
Metals 2019, 9, 771
Acknowledgments: The advice and feedback of ASPPRC sponsors is acknowledged. AK Steel, POSCO, US Steel and Baosteel are acknowledged for provision of experimental materials.
Conflicts of Interest: The authors declare no conflict of interest.
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