ABSTRACT. Numerical modelling of heat treating processes is widely used in industry in order to develop new products or optimize existing ones. Further it is well known, that the feasibility of any simulation model depends directly on the input data as well as suitable material modelling in order to reflect specific aspects of the process at hand. In this context, induction surface hardening is rather difficult to model because acquisition of material and process data is not an easy task, especially during contour hardening of gears, where very short heating times are required.

At first, a short overview of the involved process and material parameters will be given in order to point out the most important ones. For the electromagnetic part of the simulation, the experimental determination of the magnetic field and temperature dependency of the permeability will be presented. Thereafter the determination of transformation kinetics and the thermo mechanic material parameters for predicting microstructure distribution and distortion will be discussed. A final comparison between simulation results and experiment for a cylindrical specimen, using both the available material data for AISI4140 and those determined in this paper, points out the necessity of considering them for modelling this process.