Microstructure and erosion resistance of nanostructured WC-10Co4Cr coating sprayed by HVOF
ZHOU Xialiang1,2,3, CHEN Xiaoming1,2, WU Yanming1,2, ZHAO Jian1,4, LIU Wei1,4, MAO Pengzhan1,3, WANG Lirong1,3
1. Standard & Quality Control Research Institute, Ministry of Water Resources, Hangzhou 310012, China;; 2. Key Laboratory of Research on Hydraulic and Hydro-Power Equipment Surface Engineering Technology of Zhejiang Province, Hangzhou 310012, China; 3. Water Machinery and Remanufacturing Technology Engineering Laboratory of Zhejiang Province, Hangzhou 310012, China; 4. Hangzhou Mechanical Design Research Institute, Ministry of Water Resources, Hangzhou 310012, China
Abstract:To improve the slurry erosion resistance of turbine surface, nano-structured and micro-structured WC- 10Co4Cr coatings were prepared on stainless steel (0Cr13Ni4Mo) surface by HVOF. Microstructure of powders and coatings with different structure were characterized by scanning electron microscopy (SEM). The micro-hardness, bonding strength and erosion resistance were compared. Erosion failure mechanism in the sandy stream was analyzed as well. The results show that the microstructure of nano-structured WC-10Co4Cr coating prepared by HOVF is dense. Its microhardness and bond strength are higher than that of conventional coating. As well, it is found that nano-structured coating exhibits lower erosion mass loss than that of micro-structure coating. Nano-structure coating has finer grains, higher microhardness and toughness, and better micro-cutting resistance and anti-fatigue spalling properties, and can enhance the slurry erosion resistance of the coating.