GB464901A - Improvements relating to the manufacture of composite cast metal rolls - Google Patents

Abstract

In a composite roll the core metal may comprise steel with a tensile strength of 286 tons per square inch or iron containing 1,8-3,2 per cent of carbon, 1,5-0,2 per cent of silicon, 0,2-1,5 per cent of manganese, up to 1,5 per cent of chromium, up to 1 per cent of molybdenum and up to 3 per cent of nickel if desired. The metal for the chilled shell may comprise iron containing 3-4 per cent of carbon, 0,2-1 per cent of silicon, 0,2-8 per cent of manganese and, if desired, up to 10 per cent of one or more of nickel, molybdenum, vanadium, tungsten, and titanium. If steel is used as the core metal the roll must be annealed at, say, 930-940 DEG C. for six hours and, to avoid softening, the shell should be made of a ledeburitic base alloy. The silicon content should, therefore, be kept as low as possible and iron containing about 3,8 per cent of carbon, 0,27 per cent of silicon, 1,25 per cent of manganese, 1,6 per cent of chromium and 0,17 per cent of nickel has proved satisfactory.