from the conferences organized by TANGER Ltd.
In work the presented numerical models of steel hardening processes take into account thermal, mechanical phenomena and phase transformations. In the model of phase transformations, in simulations heating process continuous heating was applied, whereas in cooling process continuous cooling of the steel at issue. The phase fraction transformed (austenite) during heating and fractions during cooling of ferrite, pearlite or bainite are determined by Johnson-Mehl-Avrami formulas. The theoretical model of phase transformations was then verified by experiments. The nescent fraction of martensite is determined by Koistinen and Marburger formula or modified Koistinen and Marburger formula. The stress and strain fields are obtained using the solution of the Finite Elements Method of the equilibrium equation in rate form. The thermophysical constants occurring in constitutive relation depend on temperature and phase composite. For determination of plastic strain the Huber-Misses condition with isotropic strengthening was applied whereas for determination of transformation plasticity a modified Leblond model was used. A satisfactory agreement was found.
Keywords: Hardening, phase transformations, numerical simulations, stress© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.