DOMAŃSKI Tomasz Częstochowa Univerisity of Technology

Spoluautoři PIEKARSKA Wiesława, KUBIAK Marcin

This study describes modelling of the processes of steel hardening. The first priority was given to thermal phenomena, phase transformations in solids and mechanical processes. The issue of heat conductivity was based on the equation of apparent thermal conductivity with an integrating factor. Numerical algorithms for kinetics of phase transformations and evaluation of fractions of phases were built on the diagrams of continuous heating and cooling of tool steel (CHT and CCT). The theoretical model of phase transformations was then verified by experiments. In modelling of mechanical phenomena, the equilibrium equations and constitutive relations were adopted in the rate form. Plastic deformations are determined by the theory of non-isothermal plastic flow associated with the von Misses yield criteria. The model assumed isotropic and kinematic hardening and stress/strain effects, thermal gradients, structural changes, plastic deformations and phase transformations were evaluated. Thermal and physical properties including the Young's modulus, shear modulus and elastic limit were directly dependent on temperature and steel phase composition. The issues of thermal strain elasticity were evaluated using the finite element method. Implemented algorithms were applied in computer stimulation of hardening of low-alloy tool steel. Numerical analysis of thermal effects and phase transformations, i.e. thermal stress and deformation in mechanical phenomena in a tool steel material undergoing hardening were made.