Austenite grain size effects on isothermal allotriomorphic ferrite formation in 0.37C-1.45Mn-0.11V microalloyed steel

Allotriomorphic ferrite is the morphology of ferrite formed at relatively small undercooling below the Ae(3) temperature. Because it is the first transformation in austenite decomposition during cooling, allotriomorphic ferrite affects indirectly the subsequent austenite phase transformations, and then its study is of vital importance. The present paper is concerned to the theoretical and experimental study of the isothermal decomposition of austenite in allotriomorphic ferrite in a modern medium carbon vanadium-titanium microalloyed forging steel. This paper deals with the isothermal austenite-to-allotriomorphic ferrite as a whole, considering the specific role of different features such as prior austenite grain size (PAGS) and isothermal temperature, in nucleation and growth processes independently.