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US 3,995,678 AGranted
Induction stirring in continuous casting
AssigneeRepublic Steel Corporation
InventorsAlexander A. Zavaras, Robert E. Ryan
Life of this patent
Estimating the term…
Abstract
In continuous casting of a metal ingot which undergoes solidification progressively inwardly from its periphery while advancing through and beyond an open-ended mold, with induction stirring of the molten interior of the ingot effected by a moving magnetic field acting on the ingot throughout a stirring zone in the path of ingot advance so as to produce longitudinally directed metal flow, the applied stirring force is caused to diminish progressively and continuously toward at least one extremity of the stirring zone.
Claims19
Continuous casting procedure comprising
- a. supplying molten metal to a cooled mold having an open outlet end while
- b. advancing the metal in one direction through and beyond the mold outlet end as an ingot having a solid outer shell and a central pool of molten metal cooperatively defining a solid-liquid interface that tapers inwardly in said one direction, and
- c. causing, by application of stirring force created by a moving magnetic field in the path of ingot advance throughout a stirring region having upstream and downstream extremities spaced apart in said one direction, a circulating flow of molten metal within said pool that sweeps along said interface in a direction substantially parallel to said one direction, while
- d. producing and maintaining said magnetic field as a field for creating stirring force, in the stirring region, that decreases gradually and progressively in at least one direction from a central locality of said region to a substantially zero value at least at one extremity of said region for effecting gradual and progressive diminution of circulation-causing force in said pool in said one direction throughout the portion of said region extending to said one extremity from the central locality thereof.
1 more element
Continuous casting procedure comprising
- a. supplying molten metal to a cooled mold having an open outlet end while
- b. advancing the metal in one direction through and beyond the mold outlet end as an ingot having a solid outer shell and a central pool of molten metal cooperatively defining a solid-liquid interface that tapers inwardly in said one direction, and
- c. causing, by application of stirring force created by a moving magnetic field in the path of ingot advance throughout a stirring region having upstream and downstream extremities spaced apart in said one direction, a circulating flow of molten metal within said pool that sweeps along said interface in a direction substantially parallel to said one direction, while
- d. producing and maintaining said magnetic field, by exciting a coil disposed in surrounding relation to the path of ingot advance at said stirring region with alternating current supplied to have at least two different phases in longitudinally successive portions of the stirring region, as a field for creating stirring force, in said stirring region, that decreases gradually and progressively from a central locality of the stirring region to at least one extremity thereof over a distance, measured along the path of ingot advance, at least equal to the diameter of said coil.
1 more element
Continuous casting apparatus including
- a. an open-ended ingot casting mold;
- b. means for supplying molten metal to the interior of the mold;
- c. means for cooling the mold to effect peripheral solidification of metal contained therein;
- d. means for advancing metal from the mold along a path extending through and beyond the open end thereof as an ingot having a solid outer shell with a central pool of molten metal and a solid-liquid interface that tapers progressively inward in the direction of ingot advance;
- and
- e. a helical coil disposed in substantially coaxial surrounding relation to the path of the advancing ingot, having upstream and downstream ends and comprising a plurality of turns, energizable with alternating current supplied to have at least two different phases in longitudinally successsive portions of the coil, for producing a moving magnetic field that acts on molten metal in the pool within the ingot to cause longitudinally directed flow of molten metal along said interface;
- wherein the improvement comprises
- f. said coil having a number of turns per unit length along the axis of said coil that decreases progresssively in a downstream direction from a central locality of said coil to the downstream end thereof.
5 more elements
Continuous casting apparatus including
- a. an open-ended ingot casting mold;
- b. means for supplying molten metal to the interior of the mold;
- c. means for cooling the mold to effect peripheral solidification of metal contained therein;
- d. means for advancing metal from the mold along a path extending through and beyond the open end thereof as an ingot having a solid outer shell with a central pool of molten metal and a solid-liquid interface that tapers progressively inward in the direction of ingot advance;
- and
- e. helical coil disposed in substantially coaxial surrounding relation to the path of the advancing ingot, having upstream and downstream ends and comprising a plurality of turns, energizable with alternating current supplied to have at least two different phases in longitudinally successive portions of the coil, for producing a moving magnetic field that acts on molten metal in the pool within the ingot to cause longitudinally directed flow of molten metal along said interface;
- wherein the improvement comprises
- f. the turns of said coil having progressively increasing radii in a downstream direction from a central locality of the coil to the downstream end thereof.
5 more elements
In casting apparatus wherein an elongated metal ingot having a solid outer shell and a molten core is advanced along a defined path while undergoing progressive inward solidification, a device for creating longitudinally directed circulating flow of molten metal within the advancing ingot by induction stirring, said device including
- a. stirring means providing a plurality of electroconductive paths each extending generally transversely of the path of ingot advance, said conductive paths being disposed in successive spaced relation along and adjacent a predetermined zone of said path of ingot advance;
- and
- b. means for passing, along said conductive paths, alternating current supplied to have at least two different phases in longitudinally successive portions of said zone, for producing throughout said zone a moving magnetic field acting on an ingot advancing therethrough to effect circulating flow of molten metal within the ingot as aforesaid;
- wherein the improvement comprises
- c. successive adjacent conductive paths of said stirring means being spaced apart by distances that increase progressively from a central locality of said zone to at least one end of said zone.
2 more elements
Dependencies are inferred from the claim text.