目的 研究纳米 NiCrBSi-TiB2 涂层在 800 ℃下的 Na2SO4-30% (质量分数)K2SO4 熔盐中的热腐蚀行为。 方法 采用超音速火焰技术在中碳钢表面喷涂纳米 NiCrBSi-TiB2 涂层,以饱和 Na2SO4-30%K2SO4溶液为腐蚀介质,研究该涂层在 800 ℃时的热腐蚀行为。 结果 微米涂层晶粒粗大,Si 的扩散系数低,易出现贫 Si 富 Cr 层,形成的 Cr2O3 膜在碱性熔盐中具有较低的溶解度,对涂层具有良好的保护作用。结论 微米涂层在 Na2SO4-30% K2SO4 熔盐中具有更优的抗热腐蚀性能。

Objective To study the hot corrosion behavior of the NiCrBSi-TiB2 coating in molten Na2SO4-30% K2SO4 salt at 800 ℃. Methods The nanostructured NiCrBSi-TiB2 coating was sprayed on the surface of carbon steel by high velocity oxy-fuel (HVOF), and its hot corrosion behavior at 800 ℃ was investigated using saturated Na2SO4-30% K2SO4 solution as the corrosion medium. Results The micron coating had coarse grains, and the diffusion coefficient of Si was low, which easily led to the formation of Si-depleted Cr-rich layer, and the Cr2 O3 film formed had relatively low solubility in basic molten salt, which could well protect the coating. Conclusion The micron coating had higher resistance against hot corrosion in molten Na2 SO4 -30% K2 SO4 salt.