The reduction in the emission of CO2 in the atmosphere is one of the most important problems faced by different industries in the world. The generation of energy from oxyfuel oxygen, [1], also called Oxyfuel technology, is a matter of CO2 emission for ZERO [1,2]. Inevitably, as pipes of the heat exchangers that make up these power plants, they suffer corrosion in contact with the flue gases (H2O-CO2) at high temperatures. These pipes, made of steel or iron-chromium alloys, are not used instead of reducing corrosion. Pipes with protective coatings have already been submitted to increase resistance to corrosive processes without requiring the use of high cost alloys. One which must be inert and static at high temperatures is the case of ceramic materials. An alumina, being a suitable material to the environments characteristic of the Oxyfuel process, presents characteristics favorable to the protection [3]. Fe-9Cr samples were oxidized under conditions that simulated Oxyfuel processes in the laboratories of the Bundesanstalt Für Materialforschung Und-Prüfung (BAM) Berlin-Germany. The process occurred at 650 degree Celsius for 2000 h, in an atmosphere containing 60 percent CO2, 30 percent H2O, 7 percent N2, 2 percent O2 and 1 percent SO2. The microstructural characterization of the oxidized samples was performed in the laboratories of the National Institute of Technology (INT), using Scanning Electron Microscopy (SEM) and X-ray Energy Dispersion Spectroscopy (EDS) techniques. Risks were produced on the Al2O3 coating surface, prior to the oxidation tests, to simulate coating failures; besides the effectiveness of the alumina coating, the role of chromium as a protective medium against corrosion and other alloying elements in the oxidation process of P92 steel was also evaluated, in order to identify the oxidation mechanism. As a result of the flow of oxyfuel gases, Fe3O4, Fe2O3 and chromium-spinel layers are formed in the alloys without coating. The samples that had the alumina coating presented optimum protection, with results of a high efficiency, while the samples that had scratches presented an internal oxidation of protective chromium-spinel oxidation in the matrix just below the affected region.