A Study on Prediction of Die Life of Warm Forging by Wear(I) -Construction of Die Wear Model-

마멸에 의한 온간단조의 금형수명 예측에 관한 연구(I) -금형 마멸 모델의 정립-

The service life of tools in metal forming process is to a large extent limited by wear, fatigue fracture and plastic deformation. In warm forging processes wear is the predominant factor for operating lives of tools. To predict tool life by wear, Archard's wear model is generally applied. Usually hardness of die is considered to be a function of temperature in Archard's wear model. But hardness of die is a function of not only temperature but also operating time of die. To consider softening of die by repeated operations, it is necessary to express hardness of dies by a function of temperatures and operating time. By experiment of reheating of dies, die softening curves were obtained. Finally modified Archard's wear model in which hardness of die was expressed as a function of main tempering curve was proposed.