GB807938A - Improvements in or relating to the production of composite metal articles - Google Patents

Abstract

807,938. Casting composite articles. SOC. D'ELECTRO-CHIMIE, D'ELECTRO-METALLURGIE ET DES ACIERIES ELECTRIQUES D'UGINE. Nov. 16, 1956 [Nov. 19, 1955], No. 35171/56. Class 83 (1). A composite casting of two or more different steels or ferrous-alloys is made by casting steel or ferrous alloy into a mould containing a mass of a different steel or ferrous alloy, covered by a supernatant layer of liquid slag whose composition is such that at the melting point of the cast metal it has a low viscosity and a high interfacial tension with regard to said metal, and which is at a temperature considerably above said melting point, the temperature of the metallic mass being above the melting point of the slag, whereby the cast metal comes into contact with the metallic mass and progressively displaces the slag, and then allowing the cast metal and the metallic mass (if molten), to solidify. The metallic mass present in the mould may be solid or liquid, and may comprise two or more metals or alloys. To prevent erosion of the mass by the pouring of the next metal, an ingot mould has a sloping end wall B onto which the pouring jet impinges, and a sill S which is as thick as, or thicker than, the metallic mass already in the mould. The method may be performed by placing an ingot mould, small end up, in a larger mould, casting the first metal in the small mould, and progressively removing said mould as the ingot solidifies, pouring liquid slag into the large mould to cover the ingot, and then casting the second metal. Alternatively, the slag may be introduced before the small mould is removed. Specifications 789,657, 789,752, [Group XXXVII], 801,309 and 801,310 are referred to.