Erosion Resistance of Arc Spray Composite Coatings at High Temperature on Boiler Tubes of Pulverized Coal Fired Power Station

Several novel cored wires for producing Fe₃Al intermetallic coating, Fe₃Al/WC intermetallic coating, FeCrAl/WC intermetallic coating and FeCrNi/WC intermetallic coating by arc spraying were developed. The erosion wastage at high temperature of coatings was researched with different impingement angles and temperatures. The results indicated that impingement angle and temperature greatly affected FeCrAl/WC coating and Fe₃Al/WC coating in erosion wastage. At the same time, the FeCrAl/WC coating had little effects on different temperature while impingement angle was 90° and different impingement angle while temperature was 650°C. As compared with water wall tube material (G20 steel) of power station boiler, the erosion resistance at high temperature of Fe₃Al coating, Fe₃Al/WC coating and FeCrAl/WC coating was higher. The erosion resistance rate of Fe₃Al coating was 1.4~2.91 times of that of G20 steel when temperature was 650°C and particle was polygonal silica. At the same time, the erosion resistance rates of Fe₃Al/WC coating and FeCrAl/WC coating was 1.4~3.06 and 1.94~2.89 times respectively. The results indicated that erosive condition of high temperature flue gas and fly ash mixture in boiler tube of pulverized coal fired power station could be solved with Fe₃Al coating, Fe₃Al/WC coating and FeCrAl/WC coating.