EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Heat treatment and grinding are usually the last steps in the manufacturing chain of highly loaded mechanical components, which have a significant impact on the component’s performance. For instance, the load carrying capacity of case-hardened gears strongly depends on the surface integrity in terms of microstructure, hardness and residual stresses. The surface layer is exposed to a thermomechanical load collective during grinding, which can trigger microstructure changes and alter the surface hardness and the residual stress state. The material response to the loads from grinding depends on its initial condition, resulted from the heat treatment. To study this effect, different case-hardened variants of gear analogy samples were subjected to the same grinding process in this work. Force and sample temperature measurements were carried out during grinding to validate analytical models, describing the process load collective on the surface layer. In order to model both the case-hardening and grinding of the samples, a numerical simulation approach based on the finite element method (FEM) was implemented. The quantitative description of microstructure evolutions and residual stresses during the heat treatment and grinding are the main objective of the simulations. The numerical model is validated by comparing the simulated hardness and residual stress profiles with experimental findings. The innovative combination of experimental investigations and the numerical analysis, enabled the prediction of the surface integrity as a result of the consecutive heat treatment and grinding processes.