Fig. 1 Schematic representation of microstructure during dissolution of pearlite into austenite a and variation of carbon content along the dashed line A-A′ b

Fig. 2 Schematic representation of linearized Fe-C phase diagram with Gibbs-Thomson effect and definition of concentrations imposed at interface for CA calculation

Fig. 3 Schematic representation of sidewise planar growth of austenite into ferrite and cementite (rγ/α and rγ/θ are positions of the moving austenite fronts into ferrite and cementite, respectively)

Fig. 4 Variation of carbon concentration along dotted line indicated in Fig. 3 at different time

Fig. 5 Change in austenite interface positions predicted by CA and DICTRA

Fig. 6 Schematic representation of initial structure for austenite growing within pearlite lamella

Fig. 7 Austenite growing inside pearlite lamella with interlamellar spacing of 0.5 μm at 1073 K: a evolution of phase interface; b carbon concentration field at steady-state stage

Fig. 8 Change in local carbon concentration profile along moving interface of OD as shown in Fig. 7

Fig. 9 Change in local velocities of the \({\gamma \mathord{\left/ {\vphantom {\gamma \alpha }} \right. \kern-0pt} \alpha }\) interface (\(v_{y}^{\gamma /\alpha }\)) at different positions of B, C and D (as shown in Fig. 7) of moving austenite interface

Fig. 10 Interface shapes of growing austenite and carbon concentration profiles at steady state with varied carbon diffusion coefficient: a 2.0 \(D_{\text{C}}^{\gamma }\); b \(D_{\text{C}}^{\gamma }\); c 0.5 \(D_{\text{C}}^{\gamma }\)

Fig. 11 Evolution of velocity at position D of moving interface (\(v_{y}\)) with varying carbon diffusivity in austenite

Fig. 12 Interface shapes and carbon concentration profile of growing austenite at steady state with varied interlamellar spacings of 0.2 μm a, 0.4 μm b and 0.8 μm c

Fig. 13 Growth rate (\(v\)) and parabolic coefficient of interface shapes at steady state during austenite formation from pearlite with various interlamellar spacings