FeCrBMnSi alloy coating on steel substrate (310S) was fabricated by a high-velocity arc spraying (HVAS) process. Degradation behavior of the coatings at temperatures of 700 °C and 900 °C in air and in the coal fired boiler at (700±10) °C was studied. X-ray diffraction (XRD) and scanning electron microscopy/energydisperse spectroscopy (SEM/EDS) were used to characterize the coating as well as to analyze the corrosion products for elucidating the corrosion mechanisms. Coating exhibited dense and globular morphology and the splats were interconnected as evident from SEM analysis. The maximum microhardness of the coating was found to be 630-1060 HV. The FeCrBMnSi alloy coating has imparted necessary resistance to oxidation and showed good adherence to the 310S substrate during the exposures with no tendency for spallation of its oxide scale. © The Chinese Society for Metals and Springer-Verlag Berlin Heidelberg.