GB1480216A - Electroslag refining - Google Patents

Abstract

1480216 Etectroslag refining; continuous casting BRITISH STEEL CORP 4 Oct 1974 [5 Oct 1973] 46699/73 Heading B3F At least one electrode 6 (which may be of steel and consumable) projects into a molten slag bath 7 contained within the upper open section 2 of a body 1, a lower section 3 of which is of smaller cross-section than both the upper section and the electrode and functions as a mould for producing a casting 13 and is insulated electrically from the upper section 2, e.g. by an asbestos sheet 4. The sections 2, 3 of the body 1 are of copper and are water-cooled. The body 1 is initially mounted on (and preferably insulated from) a base plate 8 from which it is raised by a carriage 9. The electrode 6 and the plate 8 are connected to an A.C. or D.C. source. The electrode is raised or lowered to maintain the current value. The insulation of the sections 2 and 3 from each other is said to prevent electric current 16 penetrating the layer of solid slag 15 which freezes on the body walls and forming cracks therein which produce casting fins. The mould section 3 may have two cavities, from which two castings are simultaneously withdrawn by rollers. In another embodiment, the upper section is in the form of a cylindrical wall mounted on a separate annular plate which is electrically insulating, e.g. being made of zirconia. The mould is stationary and the casting is withdrawn downwardly by rollers and is tubular since a cooled mandrel extends down through an electrode which is hollow or through an annular array of electrodes and down through the mould.