Experimental and theoretical analysis of wear mechanism in hot-forging die and optimal design of die geometry

• We study three competing wear mechanisms on the worn surface in hot-forging die.
• We propose a new wear calculation model considering the wear mechanisms.
• Optimal design of mandrel die geometry is conducted.

The purpose of this study is to gain a better understanding of the wear mechanism in hot-forging die, propose a new wear calculation model to predict the die wear more accurately and present a die geometry optimization method to prolong the die lifespan. Taking the mandrel in wheel hub forging process as example, the wear mechanism was studied by SEM examinations. It was found that three competing wear mechanisms exist on the worn surface, namely adhesive wear, abrasive wear and oxidation wear. A new wear calculation model was proposed with the consideration of these three wear mechanisms. An optimal design of the mandrel geometry was carried out based on the proposed wear calculation model, forging numerical simulation, BP neural network and Sequential Quadratic Programming (SQP) algorithm. Wear tests were performed to verify the wear calculation accuracy, which shows a good agreement with the calculated result. This study will be beneficial to the accurate prediction of die wear and the optimal design of die geometry in hot-forging process.