The oxidation performance of NiCrAlY and NiCrMo coatings thermally sprayed by high velocity air-fuel (HVAF) technique has been investigated in a chloridizing-oxidizing environment, with and without a KCl deposit, at 600 °C for up to 168 h. Both coatings protected the substrate in the absence of KCl due to formation of a dense Cr-rich oxide scale. In the presence of KCl, Cl−/Cl2 diffused through a non-protective and porous NiCr2O4 scale formed on NiCrAlY, leading to formation of volatile CrCl3. On the other hand, Mo in NiCrMo stimulated the formation of a more protective Cr-rich oxide scale which increased the corrosion resistance by reducing Cl−/Cl2 diffusion.

中文翻译：

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KCl和HCl对HVAF喷涂NiCrAlY和NiCrMo涂层高温腐蚀的影响

研究了通过高速空气燃料 (HVAF) 技术热喷涂的 NiCrAlY 和 NiCrMo 涂层的氧化性能，在氯化-氧化环境中，有和没有 KCl 沉积物，在 600 °C 下长达 168 小时。由于形成了致密的富铬氧化皮，两种涂层在没有 KCl 的情况下都可以保护基材。在 KCl 的存在下，Cl−/Cl2 通过在 NiCrAlY 上形成的非保护性多孔 NiCr2O4 氧化皮扩散，导致形成挥发性的 CrCl3。另一方面，NiCrMo 中的 Mo 刺激了更具保护性的富铬氧化皮的形成，通过减少 Cl-/Cl2 扩散来提高耐腐蚀性。