Experimental Research on Refining Slag Systems Containing BaO for Ultra-Low Sulphur Steel

The experimental research on refining slag systems for ultra-low sulphur steel was carried out in a 10 kg induction furnace. It was proved that sulphur element in molten steel can be removed to less than 5×10 -6 by adding CaO-Al 2O 3-SiO 2-MgO-CaF 2 slag on the surface of molten steel and feeding CaO-BaO-CaF 2 wire into molten steel. And L s, which is the coefficient of sulphur between slag and molten steel, that is ω (S) /ω , increases by increasing I (I=ω BaO /ω CaO ). When I=5/3, L s can be up to its maximum of 633. The CaSi is effective for deep desulphurization, especially when it is added to the slag of wire feeding.