Tundish stopper rod for continuous molten metal casting

Abstract

Stopper rods for the continuous casting of molten metal have a stopper rod body, and a stopper rod tip at a lower end of the stopper rod body. The stopper rod tip defines a frustroconically shaped exterior surface which terminates in a recessed nose. The recessed nose is most preferably a curvilinear surface (e.g., a spherical segment), but non-curvilinear surfaces (e.g., prismatic, pyramidal, triangular, and quadrangular surfaces) may alternatively be employed. The frustroconically shaped exterior surface of the stopper rod tip most preferably forms an angle θ with respect to a horizontal plane which is sufficiently great so as to increase the velocity of the flowing molten metal to reduce the boundary layer thickness thereof adjacent the nozzle and stopper rod tip surfaces so as to minimize the deposition of inclusions thereon. In addition, the angle θ formed by the frustroconically shaped exterior surface is also most preferably sufficiently small so as to not detrimentally affect the lifting force sensitivities of the stopper rod.

Description

FIELD OF THE INVENTION [0001] The present invention relates generally to the casting of molten metal, such as steel, copper, aluminum and alloys thereof. More specifically, the present invention relates to stopper rods for regulating the flow rate of molten metal discharged from a tundish during a continuous casting operation. BACKGROUND AND SUMMARY OF THE INVENTION [0002] The continuous casting of molten metal involves providing an available source of molten metal in a suitable vessel, for example, a tundish or ladle, which is located physically above a mold in the continuous casting apparatus. When using a tundish as the vessel for holding the molten metal, a flow of molten metal is discharged therefrom into the mold via a tundish discharge nozzle at a flow rate which is suitable for the casting conditions. The flow rate of molten metal being discharged from the tundish nozzle is controllably regulated by a stopper rod. More specifically, the stopper rod is moveable relative to th...

AI Technical Summary

Benefits of technology

[0002] The continuous casting of molten metal involves providing an available source of molten metal in a suitable vessel, for example, a tundish or ladle, which is located physically above a mold in the continuous casting apparatus. When using a tundish as the vessel for holding the molten metal, a flow of molten metal is discharged therefrom into the mold via a tundish discharge nozzle at a flow rate which is suitable for the casting conditions. The flow rate of molten metal being discharged from the tundish nozzle is controlla

Problems solved by technology

One problem associated with controlling molten metal flow is that so-called inclusions (e.g., contaminants in the molten metal such as oxidized particles of the metal being cast) are typically present in the molten metal as it is discharged from the tundish through the nozzle.

Over time, therefore, the geometry of the orifice are defined between the tundish nozzle and th

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