Transition between partitioned and unpartitioned growth of proeutectoid ferrite in Fe-C-Xi systems

The kinetic transition between partitioned and unpartitioned growth of proeutectoid ferrite has been studied experimentally in a low alloy steel. A direct method to calculate the partitional local equilibrium (PLE)/negligible partitional local equilibrium (NPLE) transition temperature was developed from basic thermodynamic considerations. The calculated PLE/NPLE transition temperature shows a good agreement with the experiment results. The constants for parabolic growth of proeutectoid ferrite under local equilibrium and paraequilibrium models were also evaluated using the new method.