T91钢高温水蒸气氧化行为

High temperature oxidation of T91 steel in water vapour atmosphere

通过T91钢在650℃高温水蒸汽条件下的氧化实验,用静态增重法测定了T91钢的氧化动力学曲线,其氧化动力学遵循类抛物线规律;对氧化膜进行扫描电镜、X射线衍射和能谱分析.结果表明,氧化膜的氧化物类型为Fe2O3和Fe3O4,在不同的氧化时间段分别呈片状、簇状、条状和颗粒状;氧化物晶粒是通过形核和长大形成的;氧化1h时,氧化膜的表面有Cr,其后均未发现Cr,且随后的8h氧化过程中,氧化反应一直在氧化膜的外表层进行,即发生外氧化.

The oxidation behavior of T91 steel in high temperature water vapor（650℃） is studied experimentally. The oxidation kinetics curves of T91 steel have been mensurated by thermo gravimetric analyzer （TGA） method. The results show that the oxidation kinetics obeys the parabolic law. The oxide scales are examined by X-ray diffraction, scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS）. The results show that the formed oxide consists of Fe3O4 and Fe2O3; they are flaky, cluster, stripy, granular at different oxidative period. The grain size of oxide is formed with nucleating and growing up. Cr can only be identified from the surface of the oxidation film after lh＇s oxidation, when the oxidation rate is fast and the subsequent oxidizing reaction is running on the exterior surface of the oxide scale all the time, which is external oxidation. The subsequent oxidizing reaction is running on the exterior surface of the oxide scale all the time, which is external oxidation.