Wear resistant alloy coating containing tungsten carbide

Claim 1

A method of hard facing a metal substrate with an alloy coating material adapted to impart improved resistance to wear and abrasion to said metal substrate which comprises, flame spraying a fusible powder mixture onto a metal substrate by means of a flame-spraying torch, said powder mixture comprising an atomized nickel-base alloy powder of minus 100 mesh having substantially uniformly blended therewith a powder comprising agglomerates of nickel powder intimately combined with tungsten carbide powder, said agglomerates being minus 150 mesh in size, the nickel powder and tungsten carbide powder in said agglomerates each having an average particle size ranging from about 0.1 to 10 microns, the amount of tungsten carbide in said agglomerates ranging from about 70% to 90% by weight, with the nickel powder in said agglomerates ranging from about 30% to 10% by weight, the ratio of said agglomerates to said nickel-base alloy powder in said mixture being such that the total mixture has an average tungsten carbide content of about 10% to 30% by weight, the composition of said nickel-base alloy powder in said mixture comprising by weight about 2.5 to 20% Cr, about 0.5% to 6% Si, about 0.5% to 5% B, up to about 10% Fe and the balance essentially nickel, maintaining a flame on said deposited hard facing alloy to assure a molten deposit on said substrate, and then allowing said molten deposit to solidify, whereby a hard coating is obtained metallurgically bonded to said metal substrate characterized metallographically by a substantially fine uniform dispersion of hard particles comprising tungsten carbide of average size not exceeding 10 microns dispersed through a nickel-base alloy matrix at an average interparticle spacing of less than about 15 microns.

Claim 2

A method of hard facing a metal substrate with an alloy coating material adapted to impart improved resistance to wear and abrasion to said metal substrate which comprises, flame spraying a fusible powder mixture onto a metal substrate by means of a flame-spraying torch, said powder mixture comprising an atomized nickel-base alloy powder of minus 100 mesh having substantially uniformly blended therewith a powder comprising agglomerates of nickel powder intimately combined with tungsten carbide powder, said agglomerates being minus 150 mesh in size, the nickel powder and tungsten carbide powder in said agglomerates each having an average particle size ranging from about 0.1 to 10 microns, the amount of tungsten carbide in said agglomerates ranging from about 70% to 90% by weight, with the nickel powder in said agglomerates ranging from about 30% to 10% by weight, the ratio of said agglomerates to said nickel-base alloy powder in said mixture being such that the total mixture has an average tungsten carbide content of about 10% to 30% by weight, the composition of said nickel-base alloy powder in said mixture comprising by weight about 2.5 to 20% Cr, about 0.5% to 6% Si, about 0.5% to 5% B, up to about 10% Fe and the balance essentially nickel, maintaining a flame on said deposited hard facing alloy to assure a molten deposit on said substrate, and then allowing said molten deposit to solidify, whereby a hard coating is obtained metallurgically bonded to said metal substrate characterized metallographically by a substantially fine uniform dispersion of hard particles comprising tungsten carbide of average size not exceeding 10 microns dispersed through a nickel-base alloy matrix at an average interparticle spacing of less than about 15 microns.