METHODS OF SPHEROIDIZING MEDIUM AND HIGH CARBON STEELS BY SEVERE PLASTIC DEFORMATION, APPARATUS FOR SEVERE PLASTIC DEFORMATION, AND SPHEROIDIZED MEDIUM AND HIGH CARBON STEELS PREPARED THEREFROM

摘要

A method of spheroidizing medium and high carbon steels is provided to manufacture a spheroidized micro-structure the high-carbon without complex and long time heat treatment, therefore the efficiency of cold forging is improved. A method of spheroidizing medium and high carbon steels performs follows steps, a step for charging medium and high carbon steels(C) is included with 1.60 weight% through 0.40 weight% to a hard-baked apparatus including an asymmetric die; a step for performing the ECAP(Equal Channel Angular Pressing) process by the pressurized and shear-deforming the medium and high carbon steels over 0.5 of the amount of deformation; a step heat treating the deformed medium and high carbon steels in 700~900deg.C; and a step for cooling the same.