The coatings for elevated temperature erosion resistance in circulating fluidized bed (CFB) boilers were made by high velocity arc spraying process and CrB powder wire.The microstructure and phase of the coating were examined by optical microscopy(OA),electron probe microanalysis(EPMA) and Transmission electron microscopy (TEM).The properties including microhardness,adhesion strength and on-site erosion rate of the coating were measured.The failure mechanism was also discussed.The OA and EPMA results showed that the coating consisted of individual fiat lamella,thin oxide layer,porosity and very small amount of unmelted particle which characterized as different shape and color respectively.TEM results indicated that the phases within the lamella were mainly composed of α phase,amorphous phase and other nanosized particle phase of Fe23(C,B)6,Cr23C6 which precipitated from α phase or amorphous phase.The amount of amorphous phase near the substrate was more than the other area indicating that the appearance of amorphous phase was related to the high cooling rate of the coating.The microhardness was 860HV0.2.The coating exhibited high erosion-corrosion resistance,which is about six times as SA210C steel.The advantage with excellent performance,simple process and low cost made it possible to found application in power plants.