Graduate School

Project B9: Mapping the carburisation and quenching steps of case hardening by using the FEM

Person in Charge: Dipl.-Ing. Kathrin Moch

Motivation and Objectives:
For the minimisation of the hard maching cost after the case hardening, it is necessary to predict the residual stresses and the distortion, resulting out of the heat treatment, as exact as possible. To realise the this objective, the process steps carburisation and quenching of the case hardening will be mapped with the aid of the Finite Element Method (FEM). Therefore, the diffusion of the carbon will be taken into account  in the simulation of the carburisation. The resulting carbon distribution in the component will be transfered into the quenching simulation. Furthermore, homogenisation methods will be implemented to map the mechanical and thermo-physical material behaviour.
Investigations Results
  • Experiments for the modelling of the material, e.g.
    • Determination of the yield stress via hot tensile tests
    • Detection of the local heat transfer
    • Analysis of the transformation plasticity
    • Characterisation of the component condition after case hardening
  • FEM-Simulation of the carburisation with respect to carbon diffusion
  • FEM-Simulation of effects like phase transformation appearing during quenching
  • Experimental validation of the simulation results with respect to residual stresses and distortion after case hardening
  • First simulations of the carburisation
  • Comparison of the experimental and simulative results of the carbon-depth-distribution
  • Transfer of the carbon distribution after carburisation into the simulation model for quenching