图8. 不同冷却速率条件下C浓度分布与Gibbs自由能

Fig.8. Carbon concentration distribution (a) and Gibbs free energies at cooling rates of 5 ℃/min (b), 15 ℃/min (c) and 100 ℃/min (d), respectively (T₁, T₂ and T₃ are peritectic phase transformation temperatures at cooling rates of 5, 15 and 100 ℃/min, respectively. T₀-line is the thermodynamic equivalence of δ and γ. G{}_{\delta }^{\mathrm{m}}, G{}_{\gamma }^{\mathrm{m}}and G{}_{\mathrm{L}}^{\mathrm{m}} are Gibbs free energies of δ, γ and liquid, respectively. ΔG^m is the thermodynamic driving force for the transformation of δ to γ. C{}_{\delta }^{\mathrm{*}} is interfacial composition of δ. C{}_{\delta }^{\mathrm{e}}, C{}_{\gamma /\delta }^{\mathrm{e}}, C{}_{\gamma /\mathrm{L}}^{\mathrm{e}}and C{}_{\mathrm{L}}^{\mathrm{e}} are the average compositions of δ,γ/δ interface, γ/L interface and liquid, respectively)
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