Grain Boundary Segregation Behaviour of Phosphorus and Carbon under Equilibrium and Non-equilibrium Conditions in Austenitic Region of Steels

Abstract

Auger electron microscopic analyses were performed to clarify grain boundary segregation behaviour of phosphorus and carbon in the austenitic region of steel. Grain boundary migration during recrystallization and grain growth of austenite gave rise to non-equilibrium segregation which resulted in a higher solute concentration on grain boundaries than that of equilibrium segregation. The increment of segregation caused by migration depended on the boundary velocity. In recrystallization, faster diffusing elements such as carbon, segregated with higher concentrations. It was suggested that the solute sweep effect during grain boundary migration caused the non-equilibrium segregation.