On the Early Stages of the Formation Reaction of Cementite, Fe3C

Abstract

Abstract The formation of cementite, Fe3C, in thin iron foils has been studied under in-situ conditions in the temperature range from 500 °C to 600 °C by means of Mössbauer spectroscopy in time-resolved experiments at different carbon activities. Overall, the reaction shows a two-step process exhibiting two different kinetic regimes, which can be well described on the basis of a modified Johnson–Mehl–Avrami kinetics with a characteristic parameter n = 3/2. Deviations from this behaviour, occurring in the early stages of the reaction, are discussed.