METHOD OF MANUFACTURING DUAL PHASE STEEL

摘要

Disclosed is a method of manufacturing dual phase steel having hyperfine particles having an excellent wearing resistance. According to the present invention, the method of manufacturing dual phase steel includes a step for primarily annealing at a temperature high than A3 mutation temperature after hot-rolling or cold-rolling the steel; a step for performing an equal channel angular pressing (ECAP) at a temperature lower than A1 mutation temperature to the annealed steel; and a step for secondarily annealing the ECAP-treated steel at a temperature higher than the A1 mutation temperature.