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研究比较了Fe-10Si和Fe-22Si两种合金在600~700℃于ZnCl2-KCl盐膜下的氧化行为。结果表明,无盐膜下Fe-22Si合金表现出良好的抗氧化性能,而Fe-10Si合金表面生成了具有双层结构的氧化层,外层主要为Fe的氧化物,内层为Fe和Si混合氧化物。而在盐膜下两种合金均发生了加速腐蚀,表面生成了疏松多孔的腐蚀产物,并出现内腐蚀,尤其是Fe-22Si合金表面保护性膜发生退化。合金的腐蚀速率随Si含量的增加而降低,Fe-Si合金的加速腐蚀主要是由于金属表面保护膜与氯化物沉积盐发生反应所致,通过热力学相图预测了可能发生的腐蚀反应,并探讨了加速腐蚀机制以及Si的效应。
The oxidation behavior of Fe-10Si and Fe-22Si alloys at 600-700 ℃ under ZnCl2-KCl salt solution was compared. The results show that the non-salt film Fe-22Si alloy showed good oxidation resistance, and Fe-10Si alloy surface has a two-layered oxide layer, the outer layer is mainly the oxide of Fe, the inner layer of Fe and Si Mixed oxides. Both of the two alloys accelerated corrosion under the salt film, resulting in loose and porous corrosion products on the surface and internal corrosion, especially the degradation of the protective film on the surface of Fe-22Si alloy. The corrosion rate of the alloy decreases with the increase of Si content. The accelerated corrosion of the Fe-Si alloy is mainly caused by the reaction between the metal surface protective film and the chloride deposition salt, and the possible corrosion reaction is predicted by the thermodynamic phase diagram Accelerate the corrosion mechanism and the effect of Si.