Abstract

In this study, to improve the formability of the rear floor in series stamping process, the method for predicting the temperature of tools and steel sheet is proposed using FE analysis. To do this, tensile tests and straight pulling friction tests of three steel sheets are carried out at temperatures up to 300℃, and the effect of temperature on the tensile properties and the characteristics of friction are examined. The steel sheets have a higher n-value in the temperature range of about 50℃ and it is related to the maximum uniform elongation. Also, the blue shortness occurs in the temperature range of about 150℃. When the temperature is higher than 200℃, the friction coefficient increase with increasing temperature. From the FE-simulation, the effects of the punch temperature considering heat expansion in the number of stamping are examined and discussed. The technique developed in this study for estimating tool temperature can be used to develop more feasible ways to improve continuous productivity in series stamping process.

• Keywords: Clearance(틈새),FE-simulation(유한요소해석),Formability(성형성),Rear floor(리어 플로어),Series Stamping Process(연속 스탬핑 공정)