Relevant Aspects of the Allotriomorphic and Idiomorphic Ferrite Transformations Kinetics

Recently, the grain boundary−intragranular nucleation of ferrite has received great attention seeking for the improvement of the toughness in the steel, specially when conventional austenite grain refinement techniques are not enough. This paper deals with some relevant aspects about the competitive process of allotriomorphic and idiomorphic ferrite transformations in a medium carbon vanadium-titanium microalloyed steel for two different isothermal temperatures and different values of prior austenite grain sizes. It is concluded that the consideration of proeutectoid ferrite (allotriomorphic + idiomorphic) as a single transformation might lead to wrong conclusions in an analysis of the isothermal decomposition of austenite.