Abstract: A device to generate and direct electric heat 10 for use over risers, drains, pathways and pour cups during solidification in which less than 2% plasma is utilized, comprising an outer shell 20 having one open heat delivery end 25, at least one lip 30 located at the open end 25, one closed end 35, at least one electric heating element 80 affixed within the closed 35 end and refractory material 60 surrounding the electric heating element 80. A method, employing the device 10, to improve the properties of cast alloys which comprises the heating and blanketing of a molten cast surface with an atmosphere of less than 2% plasma during solidification, the atmosphere of less than 2% plasma thereby controlling temperature during the solidification and shielding the molten cast surface from the affects of oxidation.

Abstract: The ingot mould comprises a hot-top positioned inside the upper part of the mould and comprising an inner wall formed by at least one plate of a material capable of withstanding contact with a molten metal poured into the ingot mould, without being melted or fused. The thickness of the inner wall is less than that of the wall of the mould, at least one recess is provided inside the upper part of the mould wall and the inner wall of the hot-top is placed in the recess, with its surface essentially flush and aligned with the inner surface of the mould, so as to form a closure wall separating the interior of the recess from the interior of the mould.

Abstract: Disclosed is a mold structure for casting large metallic parts such as ingots so as to avoid the formation of the "shrinkage pipe" which normally develops on the exposed top surface of such castings during their solidification. The structure comprises a cap for placement on a mold which includes a diaphragm having a front surface located to intercept radiation emitted from the top surface of the cooling metal mass and to reemit radiation back thereto, and a means for returning radiation emitted from the back surface of the diaphragm such as an infrared reflector or a stack of baffles. The cap may include means for cooling the reflective surface and suitable ports which allow the interior of the mold and cap to be evacuated. Portions of the mold adjacent its open top may be provided with insulation to prevent heat loss from the metal by conduction. Various means for providing make-up heat to the top surface of the metal mass may also be included in the structure.

Abstract: A method for casting steel ingots in molds is provided wherein the upper surface of the ingot is caused to solidify before the interior of the ingot is solidified in order to provide an improved ingot having sound and homogeneous material over all the surfaces of the ingot and a good distribution of segregates throughout the cross section of the ingot. In the improved method, the surface temperature of the upper surface of the ingots is maintained at or near the liquidus temperature of the steel being casted for at least 10 seconds after casting so that the upper surface of the ingot remains fluid to allow slag inclusions to float to the upper surface of the ingot. The upper surface of the ingot is then solidified between 10 seconds and 2 minutes after casting by lowering the surface temperature of the ingot to a temperature at or near the solidus temperature of the steel so that the upper surface of the ingot solidifies before the interior of the ingot is solidified.