Abstract: In order to eliminate clogging of nozzle that caused by the the accumulation of Al2O3 which was generated in the irrational process of deoxygenation during concasting SG45VCM steel, research on the influence of different deoxidization processes on nonmetallic inclusions in steel was studied, through thermodynamic calculation and experiments. Thermodynamic calculation shows that deoxidization by using aluminum and titanium can get low dissolved oxygen level, deoxidization ability of aluminum and titanium is better than that of silicon and manganese. At the end of two kinds of deoxidization process the oxygen mass fraction in steel were similar, the lowest was 7×10-6. Size of inclusions in the new deoxidization process was small. There were various types of inclusions, and they were distributed evenly in the steel. Phenomenon of clogging of nozzle caused by the pure Al2O3 which was generated in the original process of deoxygenation could be avoided. The experiment results show that the presence of aluminum in steel can against the formation of titanium oxide, and the inclusion distribution is uniform dispersion.

Key words: steelmaking, deoxidation alloying, oxygen mass fraction, inclusions, optimize