Abstract: A method of producing cylindrical objects with one or more lobes in which the bore surfaces are completely protected by a surface layer of abrasion resistant and/or corrosion resistant alloy and which protective layer is free of any contamination by the metal of the substrate. A hard, wear resistant, and corrosion resistant nickel-based alloy is especially suitable as lining material for surface of cylindrical products, such as housings or shells used in extrusion and injection molding devices for processing halogenated resins or rubbers. The alloys will preferably also contain 0.5 to 5% silicon and 1 to 4% boron. Also disclosed is a method of producing cylindrical objects with one or more lobes in which the bore surfaces are completely protected by a surface layer of abrasion resistant and/or corrosion resistant alloy, such as the above-described metal-based alloy.

Abstract: A high strength bimetallic cylinder having a wear-resistant ferrous liner or inlay and capable of withstanding high stresses is provided by a heat treatment process wherein the cylinder steel is transformed into the austenitic phase, followed by rapidly cooling the cylinder to an intermediate temperature so that the ferrous outer housing is transformed to a bainitic structure, and then slowly cooling the cylinder to transform the ferrous liner into a martensitic structure.