Modeling Microstructure Development during Hot Working of an Austenitic Stainless Steel

A number of physically based models are combined in order to predict microstructure development during hot deformation. The models treat average values for the generation and recovery of vacancies and dislocations, recrystallization and grain growth and the dissolution and precipitation of second phase particles. The models are applied to a number of laboratory experiments made on 304 austenitic stainless steel and the model parameters are adjusted from those used for low alloyed steel mainly in order to obtain the right kinetics for the influence of solute drag on climb of dislocations and on grain growth. The thermodynamic data are obtained using Thermo-Calc© to create solubility products for the possible secondary phases. One case of wire rolling has been analyzed mainly concerning the evolution of recrystallization and grain size. The time, temperature and strain history has been derived using process information. The models are shown to give a fair description of the microstructure development during hot working of the studied austenitic stainless steel.