Enhanced mechanical properties of a hot stamped advanced high-strength steel treated by quenching and partitioning process

A 22MnB5-type steel has been investigated to generate a duplex microstructure comprising submicrometer or ultrafine retained austenite and martensite through a combination of hot stamping with quenching and partitioning process. The results indicate that the newly treated steel shows excellent mechanical properties and the total elongation of the steel increases from 6.6% to 14.8% compared with that of hot stamped and quenched steel. These improved properties can be attributed to the nanometric duplex microstructure comprising ultrafine retained austenite and martensite.