GB1389784A - Mould assembly and method for continuous or semi-continuous casting - Google Patents

Abstract

1389784 Continuous casting BRITISH ALUMINIUM CO Ltd 13 April 1973 17838/73 Heading B3F Metal such as Al, Mg, or Al- or Mg-base alloy, flows from a body 17 of the molten metal in an insulating container 15 (with a cover 16) through a number of apertures in a plate 14 of low thermal conductivity material (which may be integral with the container 15) into a mould 11 of which the inner surface for contacting the molten metal is of graphite and which is cooled by water, e.g. in a jacket 13, applied to its outer surface so that the cooled part of the surface extends downstream from a transverse plane no more than one inch downstream of the aperture plate 14. The metal is "level poured", i.e. directed to the container 15 from a furnace tap hole as a stream 18 through a launder without change of level. The use of such apparatus and method is said to reduce coarse dendrites and improve quality and be more convenient for simultaneous multiple casting. In another embodiment, the upright portion of the cover of the insulating container (26) is integral with the mould and has a separate cover-plate (27). The mould is of Al (Cu is also mentioned) and has a graphite liner (22) instead of being wholly of graphite. Water is applied to the mould outer surface at the level of the downstream surface of the aperture plate (25). The distance between this level and the outlet of the mould is not more than 2À5 inches, preferably less than 1À5 inch. The mould graphite may be soft and porous; lubricant may pass into the mould through the pores or channels instead of being applied to the inside surface directly. The graphite mould may be sprayed with copper on the outside to prevent water penetration. It may be machined from solid. As a liner, the graphite may be a shrink-fit or press-fit in the metal shell. The apertures in plate 14 are from 3/16 inch to 1 inch diameter and occupy 30-60% the effective plate area.