Process Development of Tungsten Carbide Containing Hardfacings

The protection of surfaces against erosion, abrasive or corrosive influence are becoming more important in the efforts to improve service life of components in severe environments such as road construction equipment. Tar sands operations and the oil and gas industries (particularly downhole drilling tools). Tungsten carbide containing coatings are characterized by the embedding of hard materials in a relatively soft matrix. These particles of the type WC/W2C have hardness significantly above 2000 HV but a strong capacity to resist abrasive loads [1, 2]. These particles can degrade with the formation of brittle phases. This can lead to cracks and negatively influence the hardfacing characteristics. For best results the correct alloy needs to be selected and applied under accurately controlled conditions. The Plasma Transferred Arc Welding is a process that is characterized by a low degree of dilution, excellent control options and reproducibility. Because of the numerous range of possible variables such as welding current, welding voltage, gas flows, powder feed rate etc. need to be accurately monitored and controlled.