Coupled Model for Carbon Partitioning from Martensite into Austenite During the Quenching Process in Fe-C Steels

In this paper, a coupled model for carbon partitioning from martensite into austenite during the quenching process in Fe-C steels is constructed where the carbon is permitted to partition while the martensite is continuously forming. A diffusion model of carbon at the ‘martensite/austenite interface’ is created where the interface does not move during the carbon partitioning process, and the driving force for carbon partitioning originates from the chemical potential difference. The results show that the martensitic transformation and carbon partitioning affect each other, and that the cooling rate between the martensite start temperature (M _s) and room temperature has a major effect on the volume fraction of the final retained austenite. The simulation results are shown to be in good agreement with experiments.