Abstract
	The inclusions responsible for the preferential acicular ferrite nucleation in carbon steels have been studied. Nucleation rate of acicular ferrite is expressed by various factors from which following two parameters play a very important role in this process. Increase in chemical free enthalpy change for ferritic phase nucleation due to Mn-depleted zone formation in vicinity of Ti2O3 inclusions (MnS precipitation). Decrease in interfacial energy accompanying acicular ferrite nucleation on TiN having high lattice registry with ferritic matrix. The conditions leading to the achievement of acicular ferrite as dominant phase in microstructure are analysed.