METHOD AND APPARATUS FOR CONTROLLING FLOW OF MOLTEN STEEL IN MOLD, AND METHOD FOR PRODUCING CONTINUOUS CASTINGS

摘要

A method for controlling the flow of a molten steel in a mold, which comprises applying a shifting magnetic field in such a manner as to give a braking force to the exhaust flow from an immersed nozzle, to control the flow rate (u) in the surface of the molten steel to a predetermined rate, when the flow rate (u) of the molten steel exceeds 0.32 m/sec, which is a critical flow rate for the phenomenon of catching a powder, applying a shifting magnetic field in such a manner as to rotate the molten steel in the mold in the parallel direction, to thereby control the flow rate of the molten steel to a range of 0.20 to 0.32 m/sec, when the flow rate (u) is less than 0.20 m/sec, which is a critical flow rate for the adhesion of an inclusion, and also is 0.10 m/sec or more, which is a critical flow rate for the formation of a skin in the surface of the molten steel, and applying a shifting magnetic field in such a manner as to give an accelerating force to the exhaust flow from an immersed nozzle, to control the flow rate (u) of the molten steel to a range of 0.20 to 0.32 m/sec, when the flow rate (u) is less than the critical flow rate for the formation of a skin.