Synergetic approach to die wear modelling in hot forging process

Abstract

A proposition of the hybrid model of the tool wear in hot forging is described in the paper. The idea of the model was based on distinguishing various mechanisms of the tool wear and evaluation of the mutual influence of these mechanisms. The analysis of factors, cumulative wear of which is mutually dependent, confirmed that all mechanisms influence each other in some way. To cover this, the hybrid die wear model was proposed which includes significance of each mechanism and the mutual relation between them. Additionally, to include change of material parameters, modification of these parameters was account for by a feedback, passing modified die geometry and optionally material parameters into the next iteration of die wear modelling. Developed model consists of the FE simulation to which the following process parameters are supplied by the user: wear mechanisms blocks containing adequate models, significance models and extrapolation routines for results or input parameters, component to apply computed wear value as a die geometry and control the computation of multi-iteration wear prediction. Some mechanisms blocks contain additional components for computing correction of surface parameters altered by thermomechanical fatigue, cracks or increased porosity. Numerical tests of the model were performed for the second operation in the forging of clutch wheel. Comparison of predictions and measurements confirmed improvement of the model predictive capability when synergy of the three mechanisms was accounted for.