S159 Effects of Nb interface segregation on ferrite transformation kinetics in low carbon steels

摘要

Nb addition strongly delays ferrite transformation kinetics by supressing both ferrite nucleation and growth. The reason for growth retardation is mainly caused by solute drag effect (SDE) through Nb segregation at migrating α/γ interfaces. However, the relations between Nb segregation, SDE and interface velocity have not been clarified yet. On the other hand, the presence of NbC interphase precipitation during ferrite growth will also change segregation behaviour and the resultant effect remains unclear. Therefore, the objective of this study is to clarify the effect of Nb addition on ferrite transformation by quantification of Nb interface segregation.