Die life considering the deviation of the preheating billet temperature in hot forging process

Two estimating methods are proposed for predicting the die life due to wear or plastic deformation during hot forging considering the deviation of the preheating temperature of the billet. The characteristics of the billet during electroplating or induction heating are very complex in the preheating process. Therefore, an induction heating of billet has become increasingly important as a means of reducing the heating time and an effective control of heating temperature. In this paper, to calculate the temperature distribution of the billet in the preheating process according to the parameters such as heating time, frequency and current density in high-frequency induction heating, an induction heating program has been developed. Then, FE-simulation with the proposed wear and the plastic deformation models has been carried out for the hot forging sequence of a spindle part widely used in the present continuous hot forging die. The results showed that die life is greatly affected by the wear under the conditions that exist in a given deformation process and the maximum wear occurs at the corner of the finisher die. These proposed methods of the die life could be used effectively for quantitative prediction of the die life in the hot forging process. These results might also be extended further for the study of optimization of the die change schedule to grind the die.