| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1560216 | Computational Materials Science | 2015 | 5 Pages |
•Retardation due to particles (P) on δ to γ transformation in steels was examined.•Retardation effect depends on a balance between P–δ and P–γ interfacial energies.•An equation for the retardation effect on several particle conditions was obtained.
It was reported in the authors’ previous study that second phase particles in δ phase induce a retardation effect on migration of δ–γ interface in carbon steels as is similar to the pinning effect on the grain growth in polycrystalline materials and effects of volume fraction and size of the particle were clarified. However, several other factors are expected to affect the magnitude of the retardation effect. In this study, the effect of the different interfacial energies is systematically investigated by means of two-dimensional phase-field simulations, and it is found that the magnitude of the retardation effect can be described by the parameter, Δσ = σPγ − σPδ where σPγ (σPδ) is the interfacial energy between the particle and γ (δ) phases. The large positive value of Δσ yields the strong pinning effect. In addition, it is shown that the δ–γ interface migration is accelerated when Δσ is large negative. These results originate from the increase in the total interfacial energy when Δσ > 0 and the decrease when Δσ < 0 during the interface passing through the particles. A degree of the retardation, Δa was summarized in the relation, Δa = m1(r/l2)(1 + m2Δσ), where m1 and m2 are constants and r is radius of the particle and l is particle spacing.
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