Wear resistant coating and process
AssigneeWall Colmonoy Corporation
InventorSamuel C. DuBois
Life of this patent
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Abstract
A composite article comprising a metallic substrate having an improved ductile wear and corrosion resistant surface coating thereon and metallurgically bonded thereto in which the coating comprises a nickel-chromium-tungsten base alloy matrix having uniformly dispersed therethrough a plurality of primary wear resistant particles such as tungsten carbide, for example, and secondary chromium and/or tungsten carbide crystals. The invention further encompasses the method of making the composite article by applying a particulated mixture of the metal alloy and primary wear resistant particles preferably by the Plasma Transferred Arc technique on the surface of a metallic substrate.
Claims15
A method of applying a wear and corrosion resistant alloy layer on a metallic substrate which comprises the steps of forming a powder mixture containing about 40% to about 85% by weight of prealloyed particles and about 60% to about 15% by weight of primary wear resistant particles, said prealloyed particles containing from about 0.5% to about 1.7% by weight carbon, about 22% to about 36% by weight chromium, about 0.5% to about 2% by weight boron, about 1% to about 2.8% by weight silicon, up to a maximum of about 5% by weight iron, about 3% to about 14% by weight tungsten, up to a maximum of about 2% by weight cobalt, up to a maximum of about 2% by weight of conventional residuals and impurities and the balance comprising nickel;
- heating said powder mixture to a temperature of at least about 2,350.degree. F. and effecting a melting of said prealloyed particles and applying the heated said powder mixture in the presence of an inert gas atmosphere to a metallic substrate in the form of a layer and thereafter cooling said layer.
A powder mixture adapted for application by the Plasma Transferred Arc technique to a metallic substrate for forming a metallurgically bonded wear and corrosive resistant layer comprising a nickel-chromium-tungsten base alloy matrix having substantially uniformly dispersed therethrough primary wear resistant particles in combination with secondary chromium carbide and/or tungsten carbide crystals comprising a mixture containing about 40% to about 85% by weight of prealloyed particles and about 60% to about 15% by weight primary wear resistant particles, said prealloyed particles containing from about 0.5% to about 1.7% by weight carbon, about 22% to about 36% by weight chromium, about 0.5% to about 2% by weight boron, about 1% to about 2.8% by weight silicon, up to a maximum of about 5% by weight iron, about 3% to about 14% by weight tungsten, up to a maximum of about 2% by weight cobalt, up to a maximum of about 2% by weight of conventional residuals and impurities and the balance comprising nickel.
Dependencies are inferred from the claim text.