Initial oxidation behavior of ferritic stainless steel with a sputtered NiFe2 coating for solid oxide fuel cells interconnect application was investigated in air at 800 °C to understand the transformation process from the NiFe2 alloy coating to NiFe2O4 spinel layer. The results indicated that the NiFe2 coating was initially converted to a surface scale with a layered structure consisting of a top Fe2O3 layer followed by NiFe2O4 mid-layer and an NiO inner layer. Cr oxide started to form at scale/steel interface before the coating was completely oxidized. The preferential growth orientation of Fe2O3 on the surface varied with time during the initial oxidation stage. Steel preoxidation prior to coating not only accelerated the oxidation of NiFe2 coating and the growth of NiFe2O4 layer, but also suppressed the orientated growth of Fe2O3. The surface scales on the coated steels were electrically conductive. The oxidation mechanism of the coated steels is discussed.

中文翻译：

---

铁素体不锈钢互连件与溅射 NiFe2 合金涂层的初始氧化行为

用于固体氧化物燃料电池互连应用的具有溅射 NiFe2 涂层的铁素体不锈钢的初始氧化行为在 800°C 的空气中进行了研究，以了解从 NiFe2 合金涂层到 NiFe2O4 尖晶石层的转变过程。结果表明，NiFe2 涂层最初转化为具有层状结构的表面氧化层，由顶部 Fe2O3 层、随后是 NiFe2O4 中间层和 NiO 内层组成。在涂层完全氧化之前，氧化铬开始在氧化皮/钢界面处形成。在初始氧化阶段，Fe2O3 在表面的优先生长方向随时间变化。涂层前钢的预氧化不仅加速了NiFe2涂层的氧化和NiFe2O4层的生长，而且抑制了Fe2O3的定向生长。涂层钢上的表面氧化皮是导电的。讨论了涂层钢的氧化机理。