Electropulsing-induced strengthening of steel at high temperature

摘要

Electropulsing usually promotes a metastable phase to evolve towards its equilibrium state. This work reports an alternative case, where electropulsing promotes the decomposition of the stable delta-phase in duplex stainless steel at high temperature. This decomposition enables both the gamma-phase and the sigma-phase in the steel to survive and hence to strengthen it at high temperature. The hardness of the quenched sample with electropulsing treatment is 49.4% higher than that without electropulsing treatment. A fundamental understanding of the observation is developed.