| 摘要 |
A radial bearing and method for making the same are disclosed. Radial bearings are typically used in downhole motors to control the direction of drilling in directional drilling operations. The cuttings from the bit are carried away by the drilling fluid and flow across the surfaces of the bearings before being removed from the well. The cuttings will contain sand and other hard and/or corrosive substances that will erode the surfaces of the bearings and shorten their useful life. The bearing of this invention is provided with a wear resistant surface to inhibit such erosion. The bearing of this invention is made from a bearing blank to which is applied a first overlay of mild steel with dispersed cemented metal carbide pellets. The composition of the cemented metal carbide pellets is disclosed. The first overlay may be applied by any conventional technique. A second overlay of mild steel is applied to the first overlay utilizing a MIG welding process. As the second overlay is applied, a portion of the hard metal particles in the first overlay is dispersed in the weld puddle forming the second overlay. The result is a steel hybrid matrix that can be machined down to desired dimensions and which will provide improvements in wear resistance that enable the bearing to have an extended useful life even when used in highly erosive environments. This hardbanding process may be applied to any other metal part that is subjected to erosive environments such as thrust bearings, rotors, drive shafts and the like which would benefit from an improved wear resistant surface.
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