Abstract
In warm forging above a temperature of 800°C, the dominant die failure of more than 70% is said to be adhesive wear. In order to reduce the production cost under warm and hot forging conditions, the precise prediction of die wear and countermeasures to minimize it are desired. Many research works on the prediction of die have been carried out; one of them is Archard formulation, which considers accumulated frictional work and die softening. Archard formulation was applied to the prediction of the wear of a warm backward extrusion punch, and the predicted tendencies of wear volume and profile were not identical to the test results. In this research work, we proposed the new prediction formulation for die wear using the plastic flow criteria, Dc value of die steel and Usui's formulation, which is developed for cutting tools. This new formulation for die wear is applicable to a wide temperature range, a wide area on the punch, and different die materials. We confirmed that the results of punch wear prediction obtained using the new formulation and FE analysis agreed with the experimental results of the die damage test of the warm backward extrusion type.
