This work describes a high temperature corrosion kinetics study of ∼30 % porous Fe22Cr alloys. The surface area of the alloy (∼0.02 m² g^-1) has been determined by tomographic microscopy. The weight gain of the alloys was studied by isothermal thermogravimetry in the air for 100 h at 700-900 °C. Breakaway oxidation was observed after oxidation at 850 °C (∼100 h) and 900 °C (∼30 h). The lifetime prediction shows the investigated porous alloy can be used for >3000 h at temperatures <700 °C. At temperatures ≥700 °C, the lifetime of the porous alloy is limited by the available chromium reservoir.