Effect of Combined Additional B and Mo on Recrystallization Behavior in Low Carbon Steel

Abstract

Effect of combined addition of boron (B) and molybdenum (Mo) on recrystallization behavior in austenite was investigated using low-carbon steels. The B-Mo combined added steel remarkably retarded recrystallization after hot deformation, compared to the steels added individually. Three-dimensional atom probe analysis revealed that the addition of B significantly increases the amount of Mo segregation in the austenite grain boundaries. Thermodynamic calculations based on the grain boundary phase model suggested that the interaction between B and Mo atoms increases the grain boundary segregation energy of Mo. The solute drag force was estimated by Cahn's model using the increased segregation energy of Mo, which quantitatively explained the remarkable retardation in recrystallization in the B-Mo combined steel.