| Abstract Scope |
Ferritic stainless steels (FSS) comprise a family of materials based on the Fe-Cr system with the Cr content ranging from 12 to 18 wt. %, some grades reaching 30%. FSS find a wide application in the Solid Oxide Fuel Cells (SOFCs) or Electrolyzer (SOE) technology as interconnect material. The commercially available steel grades are designed to form a slow-growing, electrically conductive, protective Cr2O3 scale at 600-850 °C.Thin-walled components made of FSS such as foils, wires or metallic foams have a limited Cr reservoir and, hence, a chemical lifetime. Analytical and numeric models were proposed to predict time to breakaway oxidation based on component geometry, alloy chemical composition and temperature. In the present work, the classical lifetime model is extended to account for the alpha-to-gamma transformation occurring in the Fe-Cr system above 830 °C. The novel model is validated by case-studies involving commercial ferritic steels and model alloys. |