Research On Wear-proof Coating Preparation And Characteristic Of Water-cooled Wall

In the industry of thermal power plants, coal-fired boilers are the main contributor to Chinese power generation. The boiler tubes are exposed to erosive environment of high temperature, high pressure, corrosion and fume erosion, water wall tubes are easily corroded in high temperature and wore by dust, which made water wall tubes become thin and burst. The direct hazard of leakage and burst of boiler tubes will affect the running safety of boiler severely and make the huge loss of economy.The protection of water wall tubes of boiler has become a technical problem that should be solved urgently.This paper analyzes corrosion and wear mechanism on water wall of circulating fluidized bed boiler, expounds the characteristics and superiority of laser cladding preparation coating technology.The usual laser cladding materials, the properties and applications of laser cladding coating on boiler tubes were introduced, reaches the possibility for generalization of this new technology on circulating fluidized bed boiler. Based on analyzing the failure mechanism of boiler tubes, three kinds of NiCr-Cr3C2+Ti composite coatings with different Ti content, which possess excellent performance of corrosion and wear resistance were designed in this paper. By using XRD, SEM, EDS, Microhardness Tester and Reciprocating Friction and Wear Testing Machine, the metallic phase constitution, microstructure, microhardness and frictional wear character are studied systematically. At last, The heat transmission of boiler tubes with and without wear-proof coatings were calculated and their effects were compared with each other.