Abstract
Problem of the phase transformation kinetics is investigated in the paper. Experimental observations and results of modelling showed that, when temperature changes are imposed, then the response of the material represented by the kinetics of changes of volume fraction of the new phase, is similar to the response of the second order inertia term in electrical systems. Therefore, possibility of application of the control theory to simulations of austenite-ferrite phase transformation in steels was the main objective of the paper. Equilibrium state was determined as a function of the temperature using ThermoCalc software. Description of the kinetics of phase transformation in transient states by the second order differential equation was proposed. Time constants in this equation were introduced as functions of the temperature. Identification of the model parameters was performed using inverse analysis of the results of dilatometric tests. Model based on the control theory was applied to describe changes of the new phase volume fraction as response to the changes of the temperature. Performed numerical tests confirmed good predictive capabilities of the model.