Fluidized bed combustors components suffer severe erosion, frequently accomplished by corrosive gases attack at elevated temperatures. The tubes damage rate depends on the boiler design bed constituents and combustion parameters, however an accelerated metal wastage is usually found in the same specific areas of different boilers. New HVOF sprayed coatings are developed for the tubii erosion corrosion protection, based on Cr3C2/ Ni-Cr, Cr-Ti-C/ Ni-Cr-Mo, and Al2O3/NiAl composite materials. The Combustion arc Fe-Cr-C coatings were found as an economical solution for relatively low erosion rate zones. The coatings properties and behavior under simulated elevated temperature erosion
conditions and in the operating boilers are discussed.
Keywords: fluidized bed combustion, erosion-corrosion, combustion arc spraying, high velocity oxygen- fuel spraying, tungsten carbide, chromium carbide, titanium carbide, nickel aluminide, aluminum oxide, elevated temperature erosion test, hardness, thermal shock resistance, bond strength