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 stud y 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 transformatio n with time for a given temperature. Moreover, the nature, size, and distri bution of the inclusions that are responsible for the intragranular nucleat ion of idiomorphic ferrite have been characterized by scanning electron mic roscopy (SEM). Finally, the influence of austenite grain size in the isothe rmal decomposition of austenite in idiomorphic ferrite has been thoroughly analyzed. An excellent agreement (higher than 90 pet in R-2) has been obtai ned between the experimental and predicted values of the volume fraction of idiomorphic ferrite.