GB919257A - Continuous casting of steel - Google Patents

Abstract

919,257. Continuous casting - machines. CENTRE NATIONAL DE RECHERCHES METALLURGIQUES. March 2, 1961 [March 24, 1960], No. 7606/61. Class 83 (1). The thickness of the compact outer skin of a continuously-cast ingot of effervescent steel is continuously measured and the rate of addition of deoxidant to the liquid metal in the mould is controlled in accordance with this measurement so as to cause the formation of a skin of predetermined thickness. The measurement of thickness may be performed by passing radiations such as gamma rays through the ingot and comparing the intensities of the incident and emergent rays, the absorption of the radiations being affected by the presence of blow-holes in their path. The addition of the deoxidant, e.g. aluminium may then be regulated manually or automatically in dependence on a signal generated by the radiation detector. The deoxidant may be supplied in solid form, as granules or aluminium wire from a bobbin, or in liquid form as from a gas-tight furnace 9, Fig. 15, the feed being regulated by controlling the gas pressure applied above the surface of the molten aluminium through a duct 17. In a modification, Fig. 14, the molten aluminium is supplied to the mould through a siphon 19.