Patent ID: 7967058
Filing Date: 2011-06-28
Classification: B22D

Abstract:
1. An apparatus for controlling a flow of a molten steel in a mold by applying a shifting magnetic field to the molten steel in a slab continuous casting machine, the apparatus comprising: a casting-condition acquiring means for acquiring at least five conditions as casting conditions, including a cast product thickness, a cast product width, a casting speed, an amount of inert gas injection into a molten steel outflow opening nozzle, and an immersion nozzle shape; a calculating means for calculating a molten steel flow velocity on a molten steel bath surface in accordance with the acquired casting conditions; a data unit that stores a mold-powder entrainment critical flow velocity and an inclusion-adherence critical flow velocity; a determining means for determining whether the acquired molten steel flow velocity is higher than the mold-powder entrainment critical flow velocity and whether the molten steel flow velocity is lower than the inclusion-adherence critical flow velocity by comparing the acquired molten steel flow velocity with the mold-powder entrainment critical flow velocity and the inclusion-adherence critical flow velocity; a control means for applying a shifting magnetic field to impart a braking force to a discharge flow from an immersion nozzle when the acquired molten steel flow velocity is higher than the mold-powder entrainment critical flow velocity, and applying a shifting magnetic field to rotate the molten steel in a horizontal direction when the acquired molten steel flow velocity is lower than the inclusion-adherence critical flow velocity; and a shifting magnetic field generating apparatus for generating a predetermined shifting magnetic field in accordance with an output from the control means.