The numerical description of case-hardening of PM-components requires material parameters in dependency of carbon concentration and porosity. Therefore a method to determine effective diffusion coefficients had to be developed. For quenching simulation the transformation behaviour was measured by quench-dilatometry, the mechanical beahviour was determined by deformation dilatometry and the thermo physical parameters were detected by DSC- and Laser-Flash testing.
|A mechanical surface treatment prior to case hardening enables to adjust a definite carbon profile during carburizing and so surface hardening of PM-components. The built-up numerical tools are able to predict the carbon depth profile and microstructure evolution in good agreement to the experimental results. The residual stress distribution, especially the compressive residual stresses in the surface layer, are overestimated. |
Nevertheless the simulations show the potential to describe case-hardening of graded porous PM-components.