An expandible and retractable enclosure surrounds a molten metal stream of metal teeming from a tundish into a casting mold, and an inert gas under slight superatmospheric pressure is introduced into the enclosure. Method and apparatus are described to expand and retract the enclosure, and also to introduce the inert gas into and to hold the enclosure in an operative position against the tundish and the mold.
Process for protecting against oxidation and/or nitridation of a liquid metal stream flowing from the outlet orifice of a ladle or a distribution vessel, comprising surrounding the pouring stream with a tube substantially throughout the height of the stream and injecting a protective gas at least around the pouring stream so as to minimize the contact of the molten metal with the ambient air and avoid the dilution of the protective gas and the aspiration of ambient air. A device for carrying out the process includes two complementary semi-shells for surrounding the pouring stream and a hinge articulating the semi-shells for opening and closing the latter.
In a continuous casting machine, the combination comprises a mould structure, a tundish car, a tundish, and a shroud for molten metal. An arrangement is provided for mounting the tundish shroud on the tundish car and for mounting the shroud adjacent the casting machine. The arrangement for mounting the shroud includes an elevating arrangement for raising the shroud into sealing engagement with a ladle when the latter is supported generally above the mould structure and for lowering the shroud to afford sufficient clearance for removal of the ladle.
A shrouding apparatus protects a molten metal stream from atmospheric contamination by establishing a protective atmosphere around the molten metal stream. The apparatus is held tightly against the vessel from which the stream is poured. The apparatus includes means for elevating and lowering the shroud, means for aligning the shroud with the pouring stream, and means for introducing a protective atmosphere to the interior of the shroud.
An apparatus for shielding a stream of molten metal during teeming consisting of a pair of cylinders aligned on a common axis by means adapted to position one cylinder against a ladle around the pouring spout and the second cylinder proximate a tundish, ingot mold or pouring trumpet. Also included are means to form a gas barrier between the cylinders to contain a shielding (inert) gas around the molten metal stream to protect the stream from contact by the ambient atmosphere and means to mount the apparatus on a pouring ladle carriage.
A shrouding sleeve for removable insertion between a tundish and an underlying mold to vertically enshroud a liquid stream issuing from the tundish to the mold wherein the shrouding sleeve consists of upper and lower substantially rigid sleeve portions. The upper sleeve is removably secured to the underside of the tundish and the lower sleeve is removably insertable for vertical alignment between the upper sleeve and the underlying mold. An annular flange is annularly secured to the bottom of the upper sleeve, and in a similar manner, annular flanges are also secured to the top and bottom of the lower sleeve. Another annular flange is also secured to the top of the underlying mold. At least one of these annular flanges is under continuous bias in the vertical direction so that when the lower shrouding sleeve is transversely inserted into vertical alignment between the upper sleeve and the mold, all of the annular flanges engage adjacent mating flanges to form a continuous shrouding sleeve under seal. The peripheral edges of the flanges may be annularly beveled to permit initial guided sliding lead-in engagement of adjacent engaging flanges under compression.
