베어링강 SUJ2의 냉간 단조성 향상을 위한 열처리에 관한 연구

Abstract

In this paper, the effect of heat treatment on forgeability is investigated and an improved heat treatment cycle is proposed for the bearing steel, SUJ2. An application example of a bearing inner race cold forging , which has small cracks in the bottom after backward extrusion and piercing, is found from a cold forging industry. The process is evaluated by finite element analysis and several heat treatment cycles are examined in order to propose an improved heat treatment cycle. The effect of heat treatment on material hardness and tool life, dimensional accuracy and forming load is revealed through experiment.