中文摘要：

应用X射线衍射（XRD）、扫描电子显微镜（能谱分析）（SEM-EDS）和电子探针显微分析等方法探讨了预涂覆碱金属硫酸盐的Co Cr Fe NiTi0.5高熵合金在0.75%SO2气氛中的腐蚀行为。结果表明：在0.75%SO2气氛中,合金的腐蚀动力学曲线遵循“抛物线”规律;合金表面生成由Ti,Cr2,Fe氧化物,尖晶石结构复杂氧化物AB2O4以及（Fe,Ni）硫化物组成的腐蚀产物;升高温度显著增加氧化膜厚度以及腐蚀影响区的孔隙密度,这使得氧化层与基体结合程度变差甚至剥离,腐蚀深度增大。Co Cr Fe Ni Ti0.5高熵合金在含硫气氛下的腐蚀归因于腐蚀初期合金元素的氧化,以及随后发生的金属氧化物的硫酸盐化、三元共晶复合盐的形成以及合金元素Fe在熔盐中的溶解反应;不仅如此,介于合金基体与金属氧化层间的腐蚀影响区还发生了合金元素（Fe,Ni）的硫化。

英文摘要：

The corrosion behaviors of CoCrFeNiTi0.5 high-entropy alloy pre-coated alkali metal sulphate in 0.75% SO2 were investiga- ted by means of X-ray diffraction （XRD） , scanning electron microscope （energy dispersive spectrometer） （SEM-EDS） and electron probe X-ray micro-analyzer. The results showed that the corrosion kinetic curves of the alloy in 0.75% SO2 followed the parabolic law. The corrosion products were mainly composed of （Ti, Cr, Fe） oxides and compound oxides with spinals structure AB2O4 as well as （Fe, Ni） xSy. Improving the corrosion temperature increased significantly both oxide films in thickness and the density of pore in the corro- sion affected zone, which resulted in the worse adhesive between the oxide film and matrix and even was apt to spall off the surface of the alloy. It was concluded that the corrosion of CoCrFeNiTi0.5 high-entropy alloy in 0.75% SO2 was attributed to the oxidation of the alloy at the beginning of the corrosion, the sulfate salinization of metallic oxide and the formation of ternary composed alkali metal sulfate as well as the dissolution of Fe in melted salt subsequently. In addition, the sulfidition of Fe, Ni occurring in the corrosion affected zone was also contributed to the corrosion.