Sensitivity Effect of Specific Heat Capacity on Combined Stress of Hot Forging Die

The service life of hot forging die is mainly decided by Stresses, including thermal, mechanical and combined stress. Stress amplitude is affected by the material properties, such as specific heat capacity. The choice of die material is very importance for improving die service life. In order to identify the effect of specific heat capacity on die stress, a 2D FE model of cake shaped workpiece is developed to analyze thermal, mechanical and combined stress of hot forging die with different level specific heat capacity. Three kinds of stress distribution are explored. The results show that thermal stress is about 10 times than mechanical stress at the die cavity surface which is the easiest failure location, and approximate linear relationship exists between stress, including thermal and combined stress, and specific heat capacity. Die material with large room temperature and temperature-sensitive specific heat capacity should be selected.