Effects of second phase particle dispersion on kinetics of isothermal peritectic transformation in Fe-C alloy

Abstract

Effects of dispersion of insolvable particles on peritectic transformation kinetics in Fe-C binary alloy system have been investigated by means of a model experiment based on a diffusion couple method. During isothermal holding of the diffusion couple of δ and liquid phase samples, the peritectic transformation proceeds by migrations of ferrite(δ)/austenite(γ) interface and liquid(L)/γinterface. It was observed that the existence of insolvable particle, ZrO 2, in δ phase retarded the migration of δ/γ interface and also the migration of L/γ interface. The retarding effect by the ZrO 2 particles becomes strong as volume fraction of particles increases and/or particle radius decreases, which is qualitatively coincident with the effect of particles on grain growth (Zener pinning). These findings were verified by multi-phase field simulations. © 2012 ISIJ.