METHOD OF TREATMENT OF STEEL IN LADLE Russian patent published in 2003 - IPC

FIELD: non- ferrous metallurgy; making low-carbon low-silicon steels. SUBSTANCE: after treatment, steel contains carbon in the amount of 0.03-0.09 mass-% and silicon in the amount of 0.01-0.04 mass-%. Proposed method includes tapping of melt from converter into ladle and supply of deoxidants, alloying and slag-forming material. At the beginning of tapping, silicon-containing is fed at flow rate of melt of 0.1 to 2.0 kg/t till working cavity of ladle is filled to 0.3 of its height. When ladle is filled to 0.5-0.95 of height of its working cavity silicon-and- manganese-containing material is fed at flow rate of 1.0-5.0 kg/t of melt together with carbonate material at flow rate of 0.5-4.0 kg/t. Then melt is purged with argon through submersible tuyere at flow rate of 0.001- 0.007 cu m/min.l of melt and aluminum is fed in form of rod at flow rate of 0.5-3.0 kg/t of melt and manganese-containing material at flow rate of 0.01-3.0 kg/t of melt. Ferrosilicon at silicon content of 40-70 mass-% may be used as silicon-containing material; ferrosilicon-manganese at content of manganese of 60-70 mass-% and silicon of 10-20 mass-% may be used as silicon-and-manganese-containing material. Limestone may be used as carbonate material at flow rate of 1.0-4.0 kg/t of melt. Dolomite may be also used as carbonate material at flow rate of 65-95 mass-%. EFFECT: reduced oxidizability of steel at simultaneous reduction of melting losses of aluminum and manganese. 6 cl, 1 tbl