Effects of N, C and Si contents and MgO on dispersion of TiN particles in Fe-1.5%Mn-0.05(0.15)%C alloy

Abstract

The crystallization and precipitation of TiN in an Fe-1.5%Mn-0.05(0.15)%C- 0.1 %Ti alloy with and without Mg deoxidation have been studied as a function of N (20-130ppm) and Si (0, 0.5 and 1.1%) contents. The size distribution of TiN particles in the sample of 0.05% C with no Mg deoxidation is bimodal and that in the sample of [%C]=0.15 is a log-normal distribution. This is explained by the difference in the degree of microsegregation which is influenced by the solidification mode. The significant effect of Si on crystallization and precipitation of TiN has not been observed. The number of MgO, TiN+MgO and TiN particles with Mg deoxidation is about two times larger than that of TiN particles with no Mg deoxidation. The number of particles with Mg deoxidation sample at [%C]=0.05 increases gradually with increasing the fraction of solid, but that at [%C1=0.15 increases drastically at interdendritic region. © 2007 ISIJ.