研究了钛合金梯度改性修复结构在800℃下氯化钠、硫酸钠混合盐中的高温腐蚀行为;计算了腐蚀动力学规律;利用扫描电镜(SEM)和X射线衍射(XRD)等分析了宏、微观形貌和相组成。结果表明:修复结构有较好的抗熔盐腐蚀性能,腐蚀线性速度常数仅为Ti600基材的39%,且二者的腐蚀动力学曲线均基本符合直线变化规律;Ti600表面腐蚀层呈多层结构,剥落现象严重,主要由疏松的金红石结构的TiO2和少量TiS、TiCl3等颗粒状粗大晶粒,以多面体规则形状堆垛,呈岛状分布,厚度180μm;修复结构表面腐蚀层覆盖均匀且薄,主要为细小的TiO2和少量Cr2O3、TiS等颗粒状氧化物,可分为外疏松层和内致密层,外疏松层较薄,内致密层致密且均匀,厚度约50μm;钛、铬的含量沿厚度方向由外向内逐渐增加,氧的分布规律相反。 The corrosion behavior of gradient modified titanium alloy structures at 800 ℃ under NaCl and sodium sulphate mixed salt was studied. The corrosion kinetics was calculated. The morphology of titanium alloy was analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) Macro, micro-morphology and phase composition. The results show that the repaired structure has better corrosion resistance to molten salt, the corrosion rate constant is only 39% Ti600 substrate, and the corrosion kinetics curves of both are in line with the linear variation; Ti600 surface corrosion layer was multi-layer The structure and spalling are serious, which are mainly composed of loose rutile TiO2 and small amount of coarse grains such as TiS and TiCl3, which are stacked in a regular polyhedral shape and are distributed in an island shape with a thickness of 180 μm. The corrosion layer on the repaired structure is covered uniformly and thinly , Mainly fine TiO2 and a small amount of Cr2O3, TiS and other granular oxides, can be divided into outer loose layer and inner dense layer, the outer loose layer is thinner, the inner dense layer is dense and uniform, the thickness is about 50μm; titanium, chromium content Along the thickness direction from outside to inside gradually increased, the oxygen distribution of the opposite.