Abstract: A trimetallic cylinder according to the preferred embodiment of the present invention includes a mild or alloy steel cylindrical body with stainless steel end rings welded or otherwise suitably joined to each end of the body. A wear and corrosion resistant alloy lining is provided for the composite cylinder, the combination resulting in improved corrosion resistance for the overall assembly.

Abstract: A wear and corrosion resistant alloy for lining cylinders used in extrusion and injection molding machines comprises at least two carbides admixed with a nickel-cobalt base alloy. The cylinder lining is preferably prepared by placing a quantity of the alloy in the cylinder and capping the ends of the cylinder. The cylinder is then heated above the melting point of the alloy and spun at a high rate of speed to centrifugally coat the inner surface of the cylinder. The cylinder's end caps are then removed and the lining finished to the correct internal diameter and finish by conventional lathe and hone means. The carbide mixture is evenly dispersed in the lining and produces a lining having desirable hardness and corrosion resistance throughout the thickness of the lining.

Abstract: A low alloy nickel-manganese steel consists essentially of carbon 0.18-0.23 weight percent, manganese 0.70-0.90 weight percent, silicon 0.20-0.35 weight percent, chromium 0.40-0.60 weight percent, nickel 0.40-0.70 weight percent, molybdenum 0.15-0.25 weight percent and the balance iron. The steel is especially well suited for use as a backing material for bimetallic cylinders prepared by the centrifugal casting process. The backing material has improved stability at the temperatures employed during centrifugally casting a layer of a lining alloy within a cylinder of the backing material. The backing also has improved weldability and less tendency to develop residual bending stresses under the temperatures and pressures encountered during manufacture and use of the cylinder.

Abstract: A wear and corrosion resistant alloy for lining cylinders used in extrusion and injection molding machines comprises tantalum carbide admixed with a nickel-cobalt base alloy. The cylinder lining is preferably prepared by placing a quantity of the alloy in the cylinder and capping the ends of the cylinder. The cylinder is then heated above the melting point of the alloy and spun at a high rate of speed to centrifugally coat the inner surface of the cylinder. The cylinder's end caps are then removed and the lining finished to the correct internal diameter and finish by conventional lath and hone means. The tantalum carbide added to the base alloy has an affinity for carbon and tends to reduce the free carbon in the final matrix producing a lining which has desirable hardness and corrosion resistance throughout the thickness of the lining.