Titanium carbide modified hardfacing for use on bearing surfaces of earth boring bits
AssigneeHughes Tool Company
InventorsEric C. Sullivan, Louis H. Barnard
Life of this patent
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Abstract
An improved hardfacing composition and method are shown for use in manufacturing an earth boring bit. The hardfacing composition is formed by combining titanium carbide with a hard-metal alloy of the iron or cobalt family. The hardfacing composition is then applied to the friction bearing surface of the rock bit.
Claims8
A method of manufacturing an earth boring bit of the type having a rotatable cutter secured to a bearing shaft on a head of the bit and at least one friction bearing surface, the improvement comprising:
- forming a hardfacing composition by combining particulate titanium carbide with a hard metal alloy, the particulate titanium carbide having a particle size less than about 10 micron;
- applying the hardfacing composition to the friction bearing surface of a selected one of the bearing shaft and rotatable cutter of the earth boring bit.
A method of manufacturing an earth boring bit of the type having a rotatable cutter secured to a bearing shaft on a head of the bit and at least one friction bearing surface, the improvement comprising:
- selecting a hard metal alloy consisting essentially of the following composition, excluding impurities:
- from about 30 to 35% by weight chromium,
- approximately 10% by weight nickel,
- approximately 12% by weight cobalt,
- approximately 5% by weight silicon,
- from about 1 to 3% by weight of carbon, and
- the balance being iron, all weight percents being based on the total weight of the hard metal alloy;
- forming a hardfacing composition by combining about 5 to 15% by volume titanium carbide with the hard metal alloy;
- and
- applying the hardfacing composition to the friction bearing surface of the earth boring bit.
A method of manufacturing an earth boring bit of the type having a rotatable cutter secured to a bearing shaft on a head of the bit and at least one friction bearing surface, the improvement comprising:
- selecting a hard metal alloy consisting essentially of the following composition, excluding impurities:
- from about 1 to 2.5% by weight carbon,
- from about 28 to 30% by weight chromium,
- from about 4 to 12% by weight tungsten, and
- the balance being cobalt, all weight percents being based on the total weight of the hard metal alloy;
- forming a hardfacing composition by combining about 5 to 15% by volume titanium carbide with the hard metal alloy;
- and
- applying the hardfacing composition to the friction bearing surface of the earth boring bit.
A method of manufacturing an earth boring bit of the type having a rotatable cutter secured to a bearing shaft on a head of the bit and at least one friction bearing surface, the improvement comprising:
- selecting a hard metal alloy powder mixture consisting essentially of the following composition, excluding impurities:
- approximately 35% by weight chromium,
- approximately 10% by weight nickel,
- approximately 12% by weight cobalt,
- approximately 5% by weight silicon,
- approximately 2% by weight of carbon, and
- the balance being iron, all weight percents being based on the total weight of the hard metal alloy powder;
- forming a powdered hardfacing composition by blending about 5 to 15% by volume powdered titanium carbide with the hard metal alloy powder mixture;
- and
- applying the powdered hardfacing composition to the friction bearing surface of the earth boring bit.
Dependencies are inferred from the claim text.