GB1260051A - Improvements in or relating to the manufacture of metal products - Google Patents

Abstract

1,260,051. Casting ingots; continuous casting. AIR REDUCTION CO. Inc. 20 March, 1969 [3 April, 1968], No. 14703/69. Heading B3F. [Also in Divisions C7 and F4] In an enclosure 11, Fig. 1, evacuated by pumps 21, 23, metal, e.g. a high- or super-alloy steel, is heated by an induction coil 26, in a crucible 24, for pouring, by way of a cooled launder 31 or 43, or 331, Fig. 4, or 331a or a hearth 343, into ingot moulds 68 or into a continuous casting mould 376 or over splash plates to produce particles; to protect the launder or hearth (which may be of copper) against erosion, a metal skull 51 or 351 is formed by the cooling, but the melt flow is maintained by beams 52 from electron guns 53 or 353. Launders 69 (mounted on a car 66 running in a mould tunnel 54 and bearing ingot moulds 68 or mounted on a car 57 also running in the tunnel and possibly bearing a ladle 59) also have coolant passages 72 so that a skull is formed and they are heated by electron beams 74. Because of the heating by the electron beams less superheat is said to be required. The enclosure 11 is divided into two chambers 12, 13 (by a wall 14 with a valved port 16 through which the launders 31 can be moved) which can be separately evacuated. In Fig. 4, there is an intermediate chamber 312a containing a vertically-displaceable ladle 391 between two launders 331, 331a which may be swung in or out of position, as indicated, to permit isolation of the chambers. There may be a vacuum enclosure for the continuous casting 378. The last chamber 313 contains the hearth 343. Such a hearth (143), Fig. 2 (not shown), extending through an unvalved port (140), has adjustable hydraulic supports (144) to control the melt flow and may be tipped repeatedly to give intermittent flow for the production of a succession of continuous castings. The top of the continuous casting (178) may be heated by a beam (152) to help form smooth sides and cause impurities to float. A hearth may be of sufficient volume to permit pouring in the chamber 13 to continue while the crucible chamber 12 is brought to atmospheric pressure for recharging. In Fig. 3 (not shown), the crucible (224) charges a travelling ladle (291) (possibly induction-heated) which then moves into an intermediate chamber (212a) before tilting to pour melt on to a hearth (243) which leads to ingot moulds (268) on a belt conveyer (284) in a mould tunnel. Pressures of 10<SP>-2</SP> to 10<SP>-1</SP> Torr may suffice but the pressure may gradually decrease from chamber to chamber to less than 1 micron in the last.