Abstract: In order to study the deoxidation and inclusion control of gear steel, this paper combines the factory experiment and thermodynamic calculation to analyze the composite deoxidation products of sulfur-containing gear steel at different smelting moments. The results show that in the smelting process, with the deoxidation reaction and the movement of deoxygenation equilibrium, the dissolved oxygen content in the steel decreases continuously, and the inclusion composition is transformed from pure Al2O3 inclusions to Al2O3-MgO-CaO-Ti2O3-CaS composite inclusions. There is a big gap between the deoxidation thermodynamics of pure iron and the actual molten steel, and the actual production can not be guided by the deoxidation thermodynamics of pure molten iron.

Key words: sulfurcontaining gear steel, deoxidization, inclusions, thermodynamics