The effectiveness of several thermal spray coatings for improving the corrosion resistance of a low alloy steel was evaluated at the temperature of 650°C under two conditions: an oxidizing atmosphere in a fluid catalytic cracking regenerator of a petrochemical unit and a simulated atmosphere in laboratory. Characterization of the phases present in the oxidized layer was carried out by X-ray diffraction (XRD), optical microscopy (OM) and scanning electronic microscopy (SEM) with X-ray energy dispersive analysis (EDS).