Grain-boundary Diffusion and Grain Alteration of Intermetallic of Fe_3Al under Sulphidation Attack

Intermetallic compound(IMC)of Fe3Al was prepared by vacuum melting.Corrosion behavior,phase change and diffusion of Fe3Al at 800-1000 ℃ in O-S mixed atmosphere were studied by scanning electron microscopy(SEM),X-ray diffraction and energy dispersive X-ray detector(EDX).Thermodynamic and kinetic mechanisms of corrosion were discussed.It was concluded that Fe3Al has perfect corrosion resistance at 600-900 ℃,but the corrosion speed increased greatly when the temperature is higher then 1000 ℃.