2007 年 93 巻 12 号 p. 769-774
Ti2O3 inclusions in steels have notable abilities as nuclei for intragranular ferrite (IGF) formations and bring grain refinement and high strength of steel. Most probable mechanism for the promotion of the IGF transition by Ti2O3 inclusions has been suggested that those absorb austenite stabilizing element of manganese from the steel phase and give the preferential ferrite formation from austenite due to raising its transition temperature. In the present work, manganese partitions between Ti2O3 and austenite-Fe were investigated at 1373-1573K for understanding the manganese absorbing behavior by Ti2O3 from the steel phase. It was clarified that the low titanium content of steel and the low heating temperature are the suitable conditions for manganese absorption by Ti2O3 and accordingly for IGF formations.