Speaker
Description
Temperature dependent strain induced precipitation of (Ti,Nb,V)(C,N) MX carbonitrides can retard static recrystallization. Predicting the role of microalloying elements on the recrystallization behavior by thermokinetic simulation is expected to support the technological process optimization and cost reduction of steel development. In this study, we assess the predictive power of recrystallization modeling for the effect of Ti, Nb, and V microalloying on recrystallization kinetics.
Isothermal double-hit compression tests are performed on a Gleeble 3800 thermo-mechanical simulator to investigate the microstructure evolution related to static recrystallization kinetics of microalloyed steel. By determination of the recrystallized fraction of austenite using the 5 % true strain method at different strains, strain rates and temperatures the static recrystallization critical temperature (SRCT) is derived for the studied microalloyed steel grade.
A recrystallization model, recently implemented into the simulation software toolbox MatCalc, is used to reproduce the experimentally determined SRCT-values. In addition, the softening fractions are evaluated as a function of time by adapted Avrami equations. Results from the MatCalc recrystallization model and the Avrami model are subsequently compared and their predictive power is assessed.