Decarbonization refinement manner of the containing Cr molten steel which

摘要

PROBLEM TO BE SOLVED: To provide a decarburize-refining method having high yield and high efficiency, by which the spitting of molten Cr-containing steel is restrained in a top-bottom combined blown AOD furnace. ;SOLUTION: The ratio L/Lo of a dent depth L on the molten steel surface and a depth Lo of the molten steel bath is regulated to 0.05-0.20. The dent depth L of the molten steel is a value obtd. by an empirical formula from a nozzle size of a lance, lance height, gas supplying pressure, gas flow rate and an overlapping ratio of the adjacent dents. The overlapping ratio of the dents is a value obtd. by an empirical formula from the number of the lance nozzles, lance nozzle size, lance height, gas supplying pressure and the gas flow rate.;COPYRIGHT: (C)2000,JPO