SURFACE SMOOTHED TOOL JOINT HARDFACING

摘要

A tool joint hardfacing containing sintered tungsten carbide granules embedded in an alloy steel matrix, with the surface substantially free of protruding granules to decrease casing wear during well drilling. The hardfacing is applied in a single application by rotating the drill pipe, providing an arc between a consummable steel wire and the pipe to create a weld puddle, and reciprocating the wire paralled to the pipe axis to create a band. Sintered tungsten carbide granules are gravity fed from an orifice directly into the arc and precipitate toward the bottom of the matrix to provide a smooth surface. The bottom of the matrix appears to be harder than the top.