| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a refining method in which the progress of a desulfurization reaction is accelerated by maintaining high Al content in molten steel during the period from the start to the end of desulfurization treatment to suppress an increase of an O activity in the molten steel, so that low-sulfur steel can be stably obtained. <P>SOLUTION: In a refining method, a flux 8 for desulfurization including calcium oxide and aluminum oxide as principal ingredients is sprayed together with carrier gas, fuel gas 9 and oxidizing gas 10 from a lance 7 provided on the top of a vacuum degassing tank 2 to blow on molten steel 3 in the vacuum degassing tank. In the refining method, a feed rate of the flux 8 for desulfurization is 0.5-0.8 kg/min per ton of molten steel, and Al content [%Al]<SB POS="POST">ME</SB>of the molten steel before the flux 8 for desulfurization is blown is equal to or more than ([%Al]<SB POS="POST">SP</SB>+0.025 M). <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
