为了应对先进航空发动机中材料研发成本大幅攀升的实际问题，亟需研发新型低成本高性能的镍基单晶高温合金。本工作以一种仅含3%Re (质量分数)的新型低成本第三代镍基单晶高温合金为研究对象，分析该合金1120 ℃高温下的氧化动力学行为与γ′相退化规律。结果表明：氧化前5 h，样品表面形成连续且均匀的三层氧化膜结构，此时氧化膜较薄(厚度仅约5 µm)，合金的氧化增重遵循次抛物线动力学规律；氧化10~100 h，Al₂O₃层间裂纹的萌生与扩展加速表面保护性氧化膜的剥落，导致样品内部的氧化加剧，反应形成AlN以及大面积的氧化反应区(ORD)，合金的氧化增重遵循线性动力学规律；氧化150 h后，ORD底部形成连续且曲折的Al₂O₃层，有效阻碍合金元素与O元素的扩散，并随着Al₂O₃层的增厚，合金的氧化增重逐渐接近抛物线动力学规律。此外，样品表面的高温氧化反应会加速合金中近表面γ′相的退化以及有害TCP相的析出。合金表面氧化膜与基体之间结合强度不足，是该基础合金非连续氧化条件下抗氧化性能低于连续氧化条件下的主要原因。

At present, the development of low-cost Ni-based single-crystal (SX) superalloys with excellent properties is urgently needed to address the increasing cost of advanced aero-engines. In this study, a novel low-cost, third-generation Ni-based SX superalloy containing 3%Re (mass fraction) was investigated to assess its oxidation behavior and γ′ phase degradation at 1120 ^oC. Results showed that during the first 5 h of oxidation, a continuous and uniform three-layer oxide film was formed on the surface of samples. Given the relatively thin oxide film, measured at approximately 5 μm, the experimental alloy followed sub-parabolic kinetics. Between 10 and 100 h of oxidation, the nucleation and propagation of cracks in the Al₂O₃ interlayer accelerated the spallation of protective oxide films. This event resulted in the increased oxidation of the matrix alloy, along with the formation of AlN and large areas in the oxidation reaction domain (ORD). These phenomena caused the transformation from sub-parabolic kinetics to linear kinetics. After 150 h of oxidation, a continuous and zigzagging Al₂O₃ layer was formed at the bottom of the ORD that could hinder the outward diffusion of alloy elements and the inward diffusion of oxygen. Consequently, the alloy gradually approached parabolic kinetics as the Al₂O₃ layer was thickened. In addition, the intense oxidation reaction on the surface accelerated the degradation of the γ′ phase and the precipitation of the topologically close pack phase near the surface. Therefore, the low bond strength between the surface oxide film and the alloy matrix primarily contributed to the deficiency of high-temperature oxidation resistance of this experimental alloy.