Turbine blades removed from the first stage of a shipboard gas turbine engine for excessive degradation were characterized. Scanning electron microscopy coupled with energy-dispersive spectroscopy, X-ray diffraction, and inductively coupled optical emission spectroscopy was used to characterize corrosion deposits and features of field hardware that are not typically obtained in controlled laboratory settings. Corrosion was associated with deposits of varying compositions on the airfoil, beneath the platform, and within cooling passages. Deposits on the airfoil were primarily sodium sulfate presumably derived from seawater. Deposits below the platform and within cooling channels were crystalline aggregates of Ca, Mg, Al, and Si compounds presumably derived from dust and sand. FactSage thermochemical calculations were performed for gas turbine environments, and results are used to explain variations in deposit chemistry. The results show that solid sodium sulfate may not be retained in some gas turbine conditions, leaving the deposits rich in Ca and Mg compounds.

中文翻译：

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船用燃气轮机叶片的热腐蚀

从船上燃气涡轮发动机的第一级中移除的涡轮叶片因过度退化而被表征。扫描电子显微镜与能量色散光谱、X 射线衍射和电感耦合发射光谱相结合，用于表征腐蚀沉积物和现场硬件的特征，这些特征通常在受控实验室环境中无法获得。腐蚀与机翼上、平台下方和冷却通道内不同成分的沉积物有关。机翼上的沉积物主要是来自海水的硫酸钠。平台下方和冷却通道内的沉积物是 Ca、Mg、Al 和 Si 化合物的结晶聚集体，推测来自灰尘和沙子。FactSage 热化学计算针对燃气轮机环境进行，结果用于解释沉积化学的变化。结果表明，在某些燃气轮机条件下，固体硫酸钠可能无法保留，从而导致沉积物富含 Ca 和 Mg 化合物。