Effect of carbon structure crystallinity on initial stage of iron carburization

Iron carburization is one of the most important reactions in iron making process. If the rate and efficiency of carburization reaction are increased, energy consumption of the process will be reduced to a large extent. The purpose of this study is to clarify the effect of carbon structure on initial iron carburization behavior for suggestion of effective carbon utilization in iron making process. Samples of different carbon structures were prepared by heat treatment of CH₄ decomposed carbon at various temperatures. Carbon structures of prepared carbon samples were analyzed by a Raman spectroscopy. For experiments, high-purity iron samples directly-contacted with carbon were prepared. A laser microscope combined with an infrared image furnace was used for heating of the sample and "in-situ" observation of carburization phenomena. Carbon concentration profile in iron sample was analyzed by a wavelength dispersion type electron probe micro analyzer. The results of this work showed that primary Fe-C liquid formation temperature became lower from 1 439 to 1 431 K with use of lower crystallization carbon. It was indicated that utilization of the lower crystallization degree of carbon structure causes formation of primary Fe-C liquid at the lower temperature.