Bit leg and cone hardfacing for earth-boring bit
AssigneeBaker Hughes Incorporated
InventorJames L. Overstreet
Life of this patent
Estimating the term…
Abstract
An earth-boring bit has a bit body, and a bit leg depending from the bit body with a circumferentially extending outer surface, a leading side and a trailing side. A cone is rotatably mounted on a cantilevered bearing shaft depending inwardly from the bit leg. A first layer of a hardfacing composition of carbide particles dispersed in a nickel-based matrix is formed on the bit leg. A second layer of a hardfacing composition of carbide particles dispersed in an iron-based matrix that is formed on the cone. The first layer of hardfacing is applied by conveying carbide particles in a nickel-based matrix through a pulsed plasma transferred arc process. The second layer of hardfacing is applied with a torch and a hardfacing tube comprising carbide particles held within an iron-based tube.
Claims14
An earth-boring bit comprising:
- a bit body;
- a bit leg depending from the bit body and having a circumferentially extending outer surface, a leading side and a trailing side;
- a cone rotatably mounted on a cantilevered bearing shaft depending inwardly from the bit leg;
- a first layer formed on the bit leg of a hardfacing composition of carbide particles dispersed in a nickel-based matrix, defining a first hardfacing layer wherein nickel comprises a primary metal of the nickel-based matrix;
- and
- a second layer formed on the cone of a hardfacing composition of carbide particles dispersed in an iron-based matrix, defining a second hardfacing layer wherein iron comprises a primary metal of the iron-based matrix.
An earth-boring bit comprising:
- a bit body;
- a bit leg depending from the bit body and having a circumferentially extending outer surface, a leading side and a trailing side;
- a cone rotatably mounted on a cantilevered bearing shaft depending inwardly from the bit leg;
- a shirttail being defined along an edge of the bit leg that corresponds with the cone;
- a layer of hardfacing formed on the shirttail, the hardfacing having a composition of carbide particles dispersed in a nickel-based matrix, defining a first hardfacing layer that contains more nickel than any other metal;
- a plurality of teeth on the cone;
- and
- a layer formed on at least a portion of the teeth of a hardfacing composition of carbide particles dispersed in an iron-based matrix, defining a second hardfacing layer that contains more iron than any other metal.
An earth-boring bit comprising:
- a bit body;
- a bit leg depending from the bit body and having a circumferentially extending outer surface, a leading side and a trailing side;
- a cone rotatably mounted on a cantilevered bearing shaft depending inwardly from the bit leg;
- a layer formed on the bit leg of a hardfacing composition of sintered tungsten carbide pellets less than about 177 microns in diameter dispersed in a nickel-based matrix consisting essentially of nickel;
- and
- a layer formed on the cone of a hardfacing composition of carbide particles dispersed in an iron-based matrix wherein iron comprises a primary metal of the iron-based matrix.
Dependencies are inferred from the claim text.