GB897252A - Metal casting apparatus - Google Patents

Abstract

897,252. Continuous-casting machines. REYNOLDS METALS CO. March 31, 1959 [April 4, 1958], No. 10936/59. Class 83 (1). Apparatus for continuously casting aluminium, steel, brass or copper comprises an annular mould shell and means 80 for directing a cooling stream of fluid against the solidified metal, the shell having a heated first wall 60 contacted by the molten metal, and a contiguous cooled second wall 52. The metal, graphite or aluminium wall 52 may be cylindrical or inwardly-, or outwardly-tapered. The wall 60 may be of asbestos or of graphite insulated from the wall 52. The lower end of the wall 52 is tapered and a meniscus 98 is formed on the metal. Lines 104 and 110 represent the freezing and solidification lines. With slow withdrawal speeds, the line 110 may be moved upwardly until, due to contraction, the ingot assumes the outline 112a and does not touch the wall 52. In a modification, the cooled wall 52, Fig. 1c, has an inclined portion 124, so that two menisci, 136, 138, are formed, or alternatively, the ingot may be made to take the form 112a or 112b. Other moulds have an intermediate tapered graphite liner 160, Fig. 2; a graphite insert 62, Fig. 3, with an insulated backing 166; a downwardly projecting lip 202, Fig. 9; a step 168, Fig. 5, between the walls 60, 52; or several steps 192, 194, 196, Fig. 8, on the cooled wall 52. The latter steps form grooves which may contain graphite lubricant. Lubricant, such as peanut oil, may also be supplied to a groove 68, Fig. 1, to pass down through the porous wall 60. In all the embodiments, a curved surface of the ingot, in the region where solidification commences, is in contact with a radially inclined surface of the mould. Several moulds 50, Fig. 10, may be fed from a common asbestos channelled block 220, the ingots being lowered on an elevator 230. The cross-section of the mould may be rectangular and the wall 60 may be heated. Furthermore, tubular ingots may be cast, the inner mould wall then being tapered towards the centre of the ingot to allow for shrinkage. U.S.A. Specifications 2,301,027, 2,367,148 and 2,740,177 are referred to.