SUMMARY
With the aid of DEFORM® software it is possible to conduct numerical simulation of workpiece phase composition during and upon heat treatment. The computation can be based on either the graphical representation of TTT diagram of the steel in question or one of the mathematical models integrated in the software, the latter being applicable if the required constants are known. The present paper gives an evaluation of differences between results of numerical simulations with various definitions of phase transformation for the heat treatment of a gearwheel and a specially prepared specimen of simple shape. It was found that the preparation of input data in terms of thorough mapping of characteristics of the material is essential.