Computer simulation of grain growth in dual-phase structures

Abstract

Grain growth in dual-phase structures has been studied by computer simulation techniques using a two-dimensional lattice model. Grain coarsening in each phase follows the cube power law. This is the result of mutual retardation of grain growth and is affected by the mutual wettability of both phases which in itself is a function of the interfacial energy ratios ρ_αα/ρ_αβ and ρ_ββ/ρ_αβ between the two phases. The Lagrange multipliers, under the incidental condition R _α+R _β = constant has been applied to the interfacial energy minimization problem and a relation between the mean grain radii and volume (or area) fractions of α and β phases, , has been obtained. It is shown that computer simulation results and experimental data on the radii of austenite and ferrite grains in dual-phase low-alloy steel and duplex stainless steel agree well with the proposed relation.