GB853853A - Continuous casting - Google Patents

Abstract

853,853. Continuous - casting machines. AMERICAN SMELTING & REFINING CO. May 9, 1957 [Aug. 27, 1956], No. 14763/57. Class 83 (1). A continuous-casting-mould comprises a graphite block, preferably a composite graphite block of halfsections, with coolant passages in its walls. Reference is made to the casting of steel, silver, nickel, aluminium, magnesium and copper. The apparatus comprises a holding- furnace 10, from which moltenmetal is poured into a tiltable pouring ladle 11, thence via a funnel 12 into the mould 13. The outlet 33 of the funnel, Fig. 2, is of inverted T-shape, with a horizontal outlet passage 36 having at its bottom a narrow slit 34, or a series of holes, to achieve a satisfactory distribution. The mould is mounted on a platform 14 which is verticallyreciprocable by a connecting-rod 39 and links 40-45, and the assembly is mounted on a carriage 15 for horizontal displacement. A starting block 17 is supported on a piston 19. The mould comprises graphite blocks 51, 51 supported within a metal casing and clamped together by bolts 54. Coolant is supplied to manifolds 50, and flows to the main cooling tubes. These each comprise an outer copper tube 85, Figs. 8 and 9, which is oversize with respect to the opening in the graphite into which it fits, and has an expansion rib 85, and a shorter inner tube 80, which has a rib 92 nesting with the rib 85, and two ribs 91 which space the inner tube from the outer tube to provide water passages therebetween. In a modification, the outer tubes 85 are elliptical and a force-fit in the graphite block. The tops of the outer tubes are sealed by caps 88, and coolant from the manifolds flows up the inner tubes and overflows down between the tubes. The openings in the graphite block are relieved at each end, as at 89, 90, so that the tubes assume a slightly larger diameter at the ends to reduce a tendency to longitudinal movement. The manifolds also supply coolant through cross-passages 68, Figs. 3 and 4, to downwardlyangled nozzles 67, and to a lower set of nozzles 84. Coolant is also sprayed from openings 82 in the bends 79 connecting the manifolds to the main cooling tubes. The mould-face has a series of recesses 74 below the nozzles 67, so as to provide a series of ribs which support the casting, and between which coolant is supplied direct to the casting from the nozzles 67. The mould-cavity is tapered. Casting processes; mould materials.-When casting oxygen-free-copper, a protective layer of particles of carbonaceous material such as flake - graphite, lampblack and pulverized - anchracite, is preferably maintained floating on the surface of the melt in the mould. This acts as a protective blanket to prevent oxygenabsorption and, due to the reciprocation of the mould, as a moving mould-wash. Alternatively, a reducing-gas may be used around the molten-metal stream. Specifications 835,854 and 835,855 are referred to.