Evaluation of Properties of Anti-Cavitation Alloy Coatings on Hydraulic Turbine

Alloy coatings of Deloro60, Stellite6, Stellite21, Sus316L and JK135 were prepared on the blade surface of hydraulic turbine by supersonic flame spraying technology. The coating quality, microstructure, chemical composition and cavitation resistance of the alloy coatings were analyzed. The results show that the alloy coatings prepared by supersonic flame spraying technology were uniformly coated and adhered well to base metal. The dispersive carbides with high hardness and strength in the alloy coatings improved the cavitation resistance of the alloy coatings. The Deloro60 alloy coating had a surface hardness of 621 HV, higher than that of other alloy coatings. When the Deloro60 alloy coating worked in real work condition for 3 850 h, the weight loss ratio was 1.6% and area loss ratio was 0.26%, higher than those of other four kinds of alloy coatings. The Deloro60 alloy coating had good comprehensive properties in cavitation condition.