The influence of titanium and vanadium on isothermal growth kinetics of allotriomorphic ferrite in medium carbon microalloyed steels

Abstract

Allotriomorphic ferrite is the morphology of ferrite formed at relatively small undercooling below the Ae3 temperature. Because it is the first transformation in austenite decomposition during cooling, allotriomorphic ferrite affects indirectly the subsequent austenite phase transformations. Although several investigations have been reported in the literature about the nucleation and growth kinetics of allotriomorphic ferrite in medium carbon microalloyed steels, there is a lack of information about the role of titanium and vanadium on this phase transformation. The purpose of the present study is to analyse the influence of both elements on the isothermal growth kinetics of allotriomorphic ferrite by means of microstructural quantitative analysis. A careful comparison of the results showed that vanadium does not affect the ferrite transformation whereas titanium speeds it up.