System, method and apparatus for hardfacing composition for earth boring bits in highly abrasive wear conditions using metal matrix materials

Abstract

A highly abrasive wear metal matrix composite hardfacing material for downhole tools is disclosed. The hardfacing material may comprise a matrix of a softer material with high hardness, such as amorphous nanocomposite steel alloys, and one or more hard component materials. The hard component materials may comprise sintered tungsten carbide, monocrystalline WC, polycrystalline WC, and the additional component of spherical cast tungsten carbide. Alternatively, a matrix of softer material, hard component materials and crushed cast tungsten carbide may be used.

1 . A hardfacing material formed from a metal matrix composite for highly abrasive wear applications, comprising:
 a matrix formed from a softer amorphous nanocomposite steel alloy and having a hardness of at least 60 Rc; and   a hard component in the matrix of softer amorphous nanocomposite steel alloy, the hard component having a higher hardness than the matrix.   
     
     
         2 . A hardfacing material according to  claim 1 , wherein the matrix comprises a range of about 20 to 90 wt % of the metal matrix composite, and the hard component comprises a range of about 10 to 80 wt % of the metal matrix composite. 
     
     
         3 . A hardfacing material according to  claim 1 , wherein the matrix comprises about 30 wt % of the metal matrix composite, and the hard component comprises about 70 wt % of the metal matrix composite. 
     
     
         4 . A hardfacing material according to  claim 1 , wherein the matrix comprises about 40 wt % of the metal matrix composite, and the hard component comprises about 60 wt % of the metal matrix composite. 
     
     
         5 . A hardfacing material according to  claim 1 , wherein the hard component comprises spherical sintered tungsten carbide pellets. 
     
     
         6 . A hardfacing material according to  claim 1 , wherein the hard component is formed from at least one of sintered tungsten carbide and cast tungsten carbide. 
     
     
         7 . A hardfacing material according to  claim 1 , wherein the hard component is formed from at least one of spherical and crushed tungsten carbide. 
     
     
         8 . A hardfacing material according to  claim 1 , wherein the hard component is formed from at least one of monocrystalline WC, macrocrystalline WC and polycrystalline WC. 
     
     
         9 . A hardfacing material according to  claim 1 , wherein the hard component further comprises spherical cast tungsten carbide. 
     
     
         10 . A hardfacing material according to  claim 1 , wherein the hard component has a particle size in a mesh range of −16 to +325, and the matrix has a hardness of at least 65 Rc. 
     
     
         11 . A downhole tool, comprising:
 a downhole tool body;   a hardfacing on the downhole tool body, the hardfacing being formed from a metal matrix composite for highly abrasive wear applications; the hardfacing comprising:   a matrix formed from a softer amorphous nanocomposite steel alloy and having a hardness of at least 60 Rc; and   a hard component in the matrix of softer amorphous nanocomposite steel alloy, the hard component having a higher hardness than the matrix.   
     
     
         12 . A downhole tool according to  claim 11 , wherein the matrix comprises a range of about 20 to 90 wt % of the metal matrix composite, and the hard component comprises a range of about 10 to 80 wt % of the metal matrix composite. 
     
     
         13 . A downhole tool according to  claim 11 , wherein the downhole tool body comprises a drill bit body having gage areas, legs, and roller cones rotatably mounted to the legs, and each of the roller cones having steel teeth extending therefrom, and wherein the hardfacing is located on at least one of the gage areas, legs, and steel teeth. 
     
     
         14 . A downhole tool according to  claim 11 , wherein the matrix comprises about 40 wt % of the metal matrix composite, and the hard component comprises about 60 wt % of the metal matrix composite. 
     
     
         15 . A downhole tool according to  claim 11 , wherein the hard component comprises spherical sintered tungsten carbide pellets. 
     
     
         16 . A downhole tool according to  claim 11 , wherein the hard component is formed from at least one of sintered tungsten carbide and cast tungsten carbide. 
     
     
         17 . A downhole tool according to  claim 16 , wherein the hard component further comprises at least one of spherical and crushed tungsten carbide. 
     
     
         18 . A downhole tool according to  claim 16 , wherein the hard component further comprises at least one of monocrystalline WC, macrocrystalline WC and polycrystalline WC. 
     
     
         19 . A downhole tool according to  claim 11 , wherein the hard component further comprises spherical cast tungsten carbide. 
     
     
         20 . A downhole tool according to  claim 11 , wherein the hard component has a particle size in a mesh range of −16 to +325, and the matrix has a hardness of at least 65 Rc. 
     
     
         21 . A method of forming a drill bit, comprising:
 (a) providing roller cones with steel teeth extending therefrom;   (b) applying a hardfacing on the steel teeth, the hardfacing being formed from a metal matrix composite for highly abrasive wear applications; the hardfacing comprising a matrix formed from a softer amorphous nanocomposite steel alloy and having a hardness of at least 60 Rc, and a hard component in the matrix of softer amorphous nanocomposite steel alloy, the hard component having a higher hardness than the matrix; and   (c) rotatably mounting the roller cones to a drill bit body.   
     
     
         22 . A method according to  claim 21 , wherein step (b) comprises applying the hardfacing to the steel teeth with a welding technique selected from the group consisting of PTA pulsed arc, PTA continuous arc, MIG pulsed arc, MIG continuous arc, TIG pulsed arc, TIG continuous arc, and oxy-acetylene. 
     
     
         23 . A method according to  claim 21 , wherein the matrix comprises a range of about 20 to 90 wt % of the metal matrix composite, and the hard component comprises a range of about 10 to 80 wt % of the metal matrix composite. 
     
     
         24 . A method according to  claim 21 , wherein the hard component is selected from the group consisting of sintered tungsten carbide, cast tungsten carbide, spherical sintered tungsten carbide pellets, spherical tungsten carbide, crushed tungsten carbide, monocrystalline WC, macrocrystalline WC and polycrystalline WC. 
     
     
         25 . A method according to  claim 21 , wherein the hard component further comprises spherical cast tungsten carbide, and the hard component has a particle size in a mesh range of −16 to +325, and the matrix has a hardness of at least 65 Rc.