A new combinatorial processing route to achieve an ultrafine-grained, multiphase microstructure in a medium Mn steel

A new combination of factors enhancing the stabilization austenite, including pre-existed austenite among quenched martensite, prior deformation, and partitioning at high temperatures is employed to create a multi-component refined microstructure in medium Mn steel (Fe–4Mn–0.31C–2Ni–0.5Al–0.2Mo, wt.%). The evolution phase fraction during processing are systematically investigated using various characterization methods. specimen after 0.4 strain deformation 73% martensite–27% 250 °C subsequent partition-annealing 600 for 20 min was composed several phases tempered fresh pearlite, 10% retained (RA) undissolved cementite. By increasing annealing temperature, pearlitic transformation suppressed, whereas recrystallization deformed martensite carbide dissolution occurred following 650 resulting an ultrafine-grained equiaxed ferrite, 32% RA along with some final cooling few precipitates. results demonstrate that combinatorial approach accelerated alloying elements from carbides largely pre-existing responsible improved intercritical dual-phase specimens. However, competitive processes also enhanced so content not increased by deformation.