A Monte Carlo simulation study of dissolution of graphite in iron-carbon melts

A Monte Carlo (MC) simulation study has been carried out on the dissolution of graphite in Fe-C melts in the temperature range 1300 degreesC to 1600 d egreesC. Atoms in graphite and iron melt were arranged on a rigid graphitic hexagonal lattice and interactions were assumed to be pairwise and short r anged. This hexagonal model of iron melts has been validated using saturati on solubility of C in iron melts. The aim of this study was to investigate the effect of the atomic nature of the interfacial region on graphite disso lution. Using canonical ensemble, simulations were carried out as a functio n of carbon content of the melt, temperature, interface orientation, and su rface roughness. A contact between graphite and melt resulted in the format ion of a broad interfacial region containing high concentrations of C and F e atoms. During the initial stages of contact, strong C-C bonds in the basa l plane hinder the dissociation of C atoms and affect the overall dissoluti on rate. As dissolution proceeds, interfacial effects become less important and dissolution is controlled by mass transfer in the melt. Interfacial ef fects do not play an important role across prismatic planes. The simulation results also show an excellent agreement with the basic trends in experime ntal results on graphite dissolution.