Electron-microscopic study of carbon interaction with products of molybdenum reduction from trioxide

Carbon interaction with products of molybdenum reduction from trioxide is studied by electron-microscopic methods. Morphology of the reaction products is determined by a stage nature of reduction which precedes carburization. If the process follows the scheme MoO3 → MoO2 → Mo → Mo2C, there are formed carbide pseudocrystals of intensively disoriented structure. They inherit the dendrite-like morphology of dioxide crystals. If the process is carried out with the MoO2:MoO3 → suboxide → Mo2C stage missing, carbide is formed due to a direct interaction of carbon with an intermediate oxide, that is the first thing and secondly, carbide pseudocrystals are characterized by more disperse structure due to strong grain orientation. Under definite conditions of reduction-carburization annealing (approximately 700 deg C, high rates of the gas flow) there may be formed a metastable MoCsub(1-x) carbide