Influence of Three Corrosive Media on High-Temperature Corrosion Behavior of T92 Steel

Three corrosive media of sulfate, chloride and coal ash were painted on the surface of T92 steel respectively. And the high-temperature corrosion behavior of T92 steel at 625℃ and 675℃ was studied through corrosion dynamitic curves, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that the corrosive media accelerated obviously the high-temperature corrosion of T92 steel. At 625℃ and 675℃, chloride had the largest corrosion promoting effect on T92 steel, followed by sulfate and fly ash in the order. The corrosion products on the surface of T92 steel painted with sulfate, chloride and coal ash were all mainly composed of Fe₂O₃ and Cr₂O₃ with complex oxides. With the increase of temperature, the corrosion rate of T92 steel painted with three kinds of corrosive media increased, and the penetration ability of O, S and Cl also improved.