中文摘要：

研究了不同Cr含量的Fe-x Cr-5Al合金（x=10%,15%,20%,原子分数）在KCl-Zn Cl2盐膜下在600℃空气中的腐蚀行为。结果表明,与无盐膜条件下合金的氧化相比,3种材料在KCl-Zn Cl2盐膜下均发生了加速腐蚀,其表面氧化铬膜在氯化物盐中发生溶解,且合金中较高Cr含量并没有有效提高合金抗氯化腐蚀的能力。在氯化盐中合金发生快速腐蚀主要是由于氧化铬溶解生成了铬酸盐,使得合金表面形成疏松的富Fe氧化产物。基于热力学相图讨论了合金在氯化物盐中的腐蚀机制,并揭示了Cr的作用机制。

英文摘要：

The corrosion of three Fe-x Cr-5Al alloys containing 10%, 15% and 20%Cr（atomic fraction） is investigated beneath KCl-Zn Cl2 deposits in air at 600 ℃. Compared to their oxidation in air without salt films, all the alloys suffer from accelerated oxidation in the presence of salt deposits due to the dissolution of chromia in the chlorides. The corrosion resistance of the alloys could not be effectively improved by the additions of high Cr content. The accelerated corrosion of Fe-x Cr-5Al alloys induced by Zn Cl2-KCl salts is attributed to the dissolution of the protective chromia in the melt, leading to the formation of loose and non-adherent scales on the surface of these alloys.The effect of Cr in Fe-Cr-Al alloys is clarified, and the accelerated degradation mechanism is also discussed in terms of the relevant thermodynamical phase stability diagrams.