The oxidation behavior of a series of iron‐aluminum alloys (to 8% Al) containing up to 0.1% carbon has been investigated over the temperature range 450° to 900°C. The oxidation rate increases and then decreases with increasing aluminum content and also with increasing temperature as the result of changes in the oxide composition. The composition of the oxide is also influenced by the carbon content of the alloy, water vapor in the atmosphere, and the partial pressure of oxygen. Perforation of the protective films that form at the higher temperatures results in the formation of scattered nodes of iron oxide. The amount of nodular oxide increases with temperature, carbon content, and water vapor and decreases with increasing aluminum concentration.