METHOD FOR DECARBONIZING MOLTEN STEEL WITH OXYGEN TOP BLOWING UNDER REDUCED PRESSURE

摘要

PURPOSE:To prevent the occurrence of splash and to efficiently execute decarbonization and temp. compensation by adding slag-making agent and slag on a molten steel surface, making oxidizing slag and adding reducing flux after blowing oxygen gas. CONSTITUTION:A slag-making agent hopper 4a and a slag-making agent charging chute 4b are installed at a side wall in a vacuum vessel 3, and the slag- making agent and the converter slag are added on the surface of the molten steel 1a in the vacuum vessel 3 during executing top blowing reduced pressure treatment to make the oxidizing slag. Further, after executing the oxygen top blowing refining, the flux, etc., incorporating Si is charged on the surface of the molten steel 1a in the vacuum vessel 3 or in the ladle 2 to execute the pressurized decarbonizing treatment. Thus, the reduced treatment time is shortened and the decarbonizing effect in low carbon area is improved.