Investigation into the Interaction of Exogenous Refractory Nanophases with a Fe–C–Si Melt (Cast Iron) at 1350°С: I. Justification of the Selection of Nanophases and the Study of Heterophase Interaction

Abstract

Per the literature, the thermodynamic stability criterion of the dispersed system of nanosized phases in metal melts is reproduced, with the latter considered the specific change in free energy (referred to the unit of change in the contact surface of the phases) of the disperse system aggregation. For iron–carbon melts with [C] > 2 wt %, according to the published scientific results, the selection of two refractory phases SiC and TiC_0.8N_0.16O_0.04 for introduction into the Fe–C–Si–Mn–P–S–O melt is justified. The preparation of nanophases, the preparation of briquettes of a composite material, and the method used to study the interfacial interaction of nanophases with sulfur and oxygen of the melt is described. It is shown that a decrease in the surfactant content of the nanophase content upon 5–10 min of exposure indicates the interaction of the surfactant with nanoparticles, and the concentration dependences are characterized by extreme minimum values.