PHYSICO-CHEMICAL BASIS FOR OBTAINING LOW-CARBON SPONGE ALLOYS

The alloying materials obtained by the technology of solid-phase reduction have higher physical and chemical parameters in comparison with traditional ferroalloys. A thermodynamic analysis of the Cr-O-C system in the temperature range of 1273-1673K was carried out, which makes it possible to clarify the possible ways of developing carbothermic reduction of Cr2O3 with the formation of stable and unstable solid products at various C/O ratios in the charge. The thermodynamic and structural shifts caused by the presence of iron in the reacting system are analyzed. The available possibilities for reducing the carbon concentration in solid reduction products are considered. A regression equation was obtained using the factor analysis method, which determines the influence of various parameters on the carbon content in the product. The kinetics of reduction of Cr2O3 in the presence of iron has been experimentally studied. The features of the effect of iron introduced into the charge mixture in the metallic form and in the form of oxide on the development of the process at different temperatures and at individual stages of Cr2O3 reduction are revealed. Ideas about the mechanism of the influence of Fe on the rate regularities and the depth of chromium reduction from the oxide phase are developed.