WC-M coating to improve resistance of hydraulic turbines to cavitation erosion and abrasion
(Department of Mechanical Engineering,
Kunming University of Science and Technology, Kunming 650051, China)
Kunming University of Science and Technology, Kunming 650051, China)
Abstract: WC-M hard-faced ceramic coating was made on the substrate of steel by means of high velocity oxygen-fuel flame (HVOF) thermal spraying. The resistance of this coating to cavitation erosion and abrasion (CEA) is about 2.5 times higher than that of 18-8 stainless steel, and is about 1.5 times higher than that of Stellite alloy (CoCrWC) made in America. When this coating were applied to the hydraulic power stations with more silt content in the flow water, which reaches 50kg/m3, the resistance of above-mentioned coating to CEA was about 2 times to that of NiCr alloy coating, and is about 4-5 times to that of OCr13Ni4Mo stainless steel. In addition, the micro-hardness, microstructures and electron probe analyzing of the WC-M coating are all discussed.
Key words: WC-M coating; cavitation erosion; abrasion hydraulic turbines