GB1491864A - Continuous casting - Google Patents

Abstract

1491864 Continuous casting ALCAN RESEARCH & DEVELOPMENT Ltd 5 Nov 1974 [6 Nov 1973] 51560/73 Heading B3F Al or Al alloy, such as magnesium silicide alloy, is cast at a rate in the range 3¢-12 in./ min. in an open-ended cooled (metal) mould of “-13/4 in. length and which the molten metal enters from an insulated upper section 6, holding a metallostatic pressure head in the range 1¢-6 in., above the cooled mould, and the values of the casting rate and pressure head are selected with respect to the Fig. 3 curves G, C, H, D, E and F (corresponding, respectively, to casting rates of 3¢, 4, 5, 6, 8 and 10 in./min.) to obtain values co-ordinated with the values of the mould length which correspond to a point said to be predictable to provide a smooth strand surface, i.e. a point in an area enclosed by the curves and the horizontal axis of the graph. The mould length and casting rate may be such as to permit a variation of one inch in the pressure head. The emerging strand 5 is cooled by direct application of coolant to its surface and may be of 3-9 ins. diameter. The casting machine may have several moulds and there may be an overhang of the upper section 6 of #-2 ins. There may be a gap up to 0À01 in. between the section and mould 1. The stool on which the ingot is cast may have a raised central area, e.g. for a 6 in. diameter casting the central 3 in. may be raised “ in.