Abstract

The purpose of this work is to investigate the working limit of carbon steel and forging condition of cold forging. The fracture criteria which was proposed by Oyane and Osakada was used. Compression test, hardness study and tension test by Oyane's creteria, microstructure study by Osakada's were carried out. The results were compared with each other. It was found that working limit on compressive hydrostatic stress is increased in comparison with that of tensile stress field and can be forecasted the fracture limit of closed cold forging.

Keywords

• Cold Forging;
• Closed Forging;
• Working Limit;
• Fracture Strain;
• Ductile Fracture;
• hydrostatic Stress

• 냉간단조;
• 밀폐단조;
• 파단변형률;
• 연성파괴;
• 정수압응력;