Abstract Limited information is available on the oxidation mechanism of accident tolerant claddings (ATC) Kanthal APMT and T91 at the onset of beyond design-basis accident (BDBA) conditions. We characterized the surface of these ATC alloys after steam and air exposure at 1200 °C for 2 h, defining the oxidation mechanism. Thickness and composition were analyzed with microscopy, Raman spectroscopy, and synchrotron diffraction. Our results demonstrate that APMT forms a compact and homogeneous α-Al2O3 layer when exposed to air or steam. T91 forms a heterogeneous porous layer, containing a mixture of Cr- and Fe-based oxides, whose composition changes with the exposure environment.

中文翻译：

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Kanthal APMT 和 T91 在超出设计基准事故温度下的氧化特性

摘要 在超设计基准事故 (BDBA) 条件开始时，关于容灾覆层 (ATC) Kanthal APMT 和 T91 的氧化机制的信息有限。我们表征了这些 ATC 合金在 1200 °C 下暴露于蒸汽和空气 2 小时后的表面，确定了氧化机制。用显微镜、拉曼光谱和同步加速器衍射分析厚度和组成。我们的结果表明，当暴露于空气或蒸汽时，APMT 会形成致密且均质的 α-Al2O3 层。T91 形成异质多孔层，包含 Cr 和 Fe 基氧化物的混合物，其成分随暴露环境而变化。