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-Al2O3-SiO2-MgO-CaF2 slag on the surface of molten steel and feeding CaO-BaO-CaF2 wire into molten steel. And Ls, which is the coefficient of sulphur between slag and molten steel, that is ω(S)/ω[S], increases by increasing I (I=ωBaO/ωCaO). When I=5/3, Ls 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.