Ultrahard sintered carbide particles in hardfacing for earth-boring bit
AssigneeBaker Hughes Incorporated
InventorJames L. Overstreet
Life of this patent
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Abstract
A hardfacing composition for downhole well tools, such as earth-boring bits, contains sintered ultrahard particles. The ultrahard particles consist of tungsten carbide grains, cobalt and vanadium. The ultrahard particles are dispersed within a matrix metal of iron, nickel or alloys thereof. The composition may also have sintered tungsten carbide particles of a larger size than the ultrahard particles. The ultrahard particles have a greater hardness than the sintered tungsten carbide particles. The ultrahard particles and the sintered tungsten carbide particles may be in a spherical pellet form. Other hard metal particles may be in the composition.
Claims21
A hardfacing composition, comprising:
- sintered ultrahard pellets, each consisting of tungsten carbide grains, cobalt, and vanadium;
- and
- a matrix metal comprising iron, nickel, or alloys thereof, the sintered ultrahard pellets dispersed in the matrix metal.
A hardfacing composition, comprising:
- spherical sintered ultrahard pellets comprising tungsten carbide grains, elemental cobalt, and elemental vanadium;
- and
- a matrix metal comprising iron, nickel, or alloys thereof, the spherical sintered ultrahard pellets dispersed in the matrix metal.
An earth-boring bit comprising:
- a body;
- a plurality of bit legs;
- a plurality of cones rotatably mounted to the plurality of bit legs;
- hardfacing on at least one of the plurality of bit legs and the plurality of cones, and comprising:
- spherical sintered ultrahard pellets comprising tungsten carbide grains, elemental vanadium, and at least one of cobalt, iron, and nickel;
- spherical sintered tungsten carbide pellets of a larger diametrical size than the spherical sintered ultrahard pellets;
- and
- a matrix metal comprising iron, nickel, or alloys thereof, the spherical sintered ultrahard pellets and the sintered tungsten carbide pellets dispersed in the matrix metal.
Dependencies are inferred from the claim text.