Creep behavior of commercial FeCrAl foils: Beneficial and detrimental effects of oxidation

Creep tests were performed at 875 °C and 1050 °C on commercially available FeCrAl foils (∼50 μm, 2 mil thickness) over a wide range of stress and duration. The oxide scales formed on the creep specimens were analyzed and compared to those that formed on unstressed specimens to assess the effect of stress and strain on oxide growth behavior. Below a specific stress threshold, the creep rate becomes moderately dependent on the applied load, the lifetime independent of that load, and rupture occurs due to the onset of breakaway oxidation. A creep rate model based on the strengthening of the FeCrAl foils due to load-bearing by the thermally grown alumina scale was observed to be in good agreement with the experimental results.