Axel Johnson Metals, Inc.

A. Johnson Metals Corporation

Charles H Entrekin

Howard R Harker

Janine C Borofka

Robert A Borowski

In the disclosed embodiments, vacuum casting of metal ingots is effected by melting metal in a hearth, directing molten metal from the hearth through a hearth outlet to one of a series of mold segments positioned on the periphery of a rotatable drum, and directing an energy beam from an electron gun or plasma gun toward the surface of the molten metal being poured into the mold segment to control solidification of the ingot. After the mold segment has been filled, the drum is indexed to position an adjacent mold segment beneath the hearth outlet. The energy beam is directed toward the surface of the completed ingot in the adjacent segment as well as toward the mold segment being filled to form a smooth surface on the solidified ingot.

Static vacuum casting of ingots

In the representative embodiment described in the specification, continuous casting of fine-grain ingots is effected by supplying molten metal to a mold in which the metal is solidified and an ingot is withdrawn downwardly and controlling the temperature in the central region of the molten metal above the ingot at a level at which small crystallites of metal are formed, but large quantities of solid material are not formed. The desired temperature level may be maintained by visual observation of the surface of the metal or pyrometric detection of the temperature of the surface and control of a directional energy input device such as an electron beam gun or a plasma torch to supply sufficient energy to maintain the desired temperature level. The typical apparatus described in the specification includes a cold hearth containing a pool of molten metal which is supplied to the mold and energy input devices, which may be electron beam guns or plasma torches, for melting the material in the hearth and maintaining the temperature of the molten material in the hearth and the mold at the desired levels, along with temperature detectors for detecting the temperature of the molten metal in the hearth and the mold, and a control unit for controlling the energy input devices for the hearth and the mold.

Continuous casting of fine grain ingots

In the particular embodiment of an electron beam cold hearth refining arrangement described in the specification, two separate hearth segments are disposed at right angles to each other and raw material is supplied to a melt area at the end of the first hearth segment remote from the second hearth segment. Molten material is poured from the opposite end of the first hearth segment into the adjacent end of the second hearth segment and refined molten material is poured into a mold from the opposite end of the second hearth segment. To prevent spattering of unrefined material into the mold or the adjacent refining area of the second hearth segment a baffle is positioned in the angle between the two mold segments.

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Coatesville, PA, United States of America

Charles H Entrekin