Modeling of kinetics of isothermal idiomorphic ferrite formation in a medium-carbon vanadium-titanium microalloyed steel

The present article is concerned with the theoretical and experimental study of the growth kinetics of idiomorphic ferrite in a medium-carbon vanadium-titanium microalloyed steel. A theoretical model is presented to calculate the evolution of isothermal austenite-to-idiomorphic ferrite transformation with time for a given temperature. Moreover, the nature, size, and distribution of the inclusions that are responsible for the intragranular nucleation of idiomorphic ferrite have been characterized by scanning electron microscopy (SEM). Finally, the influence of austenite grain size in the isothermal decomposition of austenite in idiomorphic ferrite has been thoroughly analyzed. An excellent agreement (higher than 90 pct in R ²) has been obtained between the experimental and predicted values of the volume fraction of idiomorphic ferrite.