Abstract
In order to elucidate the reaction between oxides and sulphur in molten steel during solidification, the effect of composition of oxides in continuously cast steels has been observed and analyzed. The results obtained are as follows.
CaO-SiO2-Al2O3 and CaO-SiO2 oxides are observed in low Al content steel (Al=0.005mass%) and CaO-Al2O3 oxides are observed in high Al content steel (Al=0.031mass%). CaO-SiO2-Al2O3 and CaO-Al2O3 oxides have higher S content than CaO-SiO2 oxides. High S content in oxides was obtained with high liquid fraction and high sulphide capacity of oxides at the solidification temperature of the steel.
Because desulphurization by oxides which have high sulphide capacity and high liquid fraction occurs during solidification, S segregated in the center of slab is absorbed by the oxides.
