Oxidation of the Fe-base alloy T22 in humid air at 500 °C was investigated. The samples were exposed for up to 1000 h at 1 bar and 20 bar. The influence of three furnace tube materials, alumina, ET45 and quartz glass, on the oxide scale morphology was investigated. Samples and their cross sections were examined using optical microscopy, scanning electron microscopy, electron probe micro analysis and Raman spectroscopy. Multilayered oxide scales consisting of hematite, magnetite and Fe–Cr spinel were found on all samples. However, the composition and morphology of the oxide scales depend on the furnace tube material and on the system pressure. The system pressure is assumed to change the reaction equilibria and adsorption rates. The tube material changed the initial gas composition by formation of volatile Cr species. This volatilization rate increased at higher system pressures.

研究了铁基合金 T22 在 500 °C 潮湿空气中的氧化。样品在 1 bar 和 20 bar 压力下暴露长达 1000 小时。研究了三种炉管材料氧化铝、ET45 和石英玻璃对氧化皮形貌的影响。使用光学显微镜、扫描电子显微镜、电子探针显微分析和拉曼光谱检查样品及其横截面。在所有样品上都发现了由赤铁矿、磁铁矿和 Fe-Cr 尖晶石组成的多层氧化皮。然而，氧化皮的成分和形态取决于炉管材料和关于系统压力。假定系统压力会改变反应平衡和吸附速率。管材料通过形成挥发性 Cr 物质改变了初始气体成分。这种挥发率在较高的系统压力下增加。