航空航天领域对高温合金性能要求不断提高，而主元素成分调控法已经达到优化合金性能瓶颈，难以继续 通过调整主元素添加比来显著提升高温合金的性能。 稀土是一种重要的微合金化元素，微量的稀土元素添加就可对高 温合金组织及性能产生显著影响。 采用工业级1t真空感应熔炼方法制备了K465母合金锭，冶炼过程添加了Ce和Y 稀土元素，以提升该铸造高温合金性能。采用OM对添加Ce和Y稀土元素的母合金以及固溶处理后组织进行了观察， 利用SEM、能谱仪(EDS)对母合金微观组织进行系统性表征，利用电子高温持久试验机对固溶热处理合金进行室 温拉伸与高温持久性能试验。研究结果表明，添加稀土元素后的组织类型未发生转变，主要由基体相γ相、强化相γ′相、 (γ+γ′)共晶相以及碳化物构成，析出γ′相具有较高的立方度。 抗拉强度和伸长率分别可达到887MPa和4.0%，975℃ /225 MPa 条件下持久寿命88.5h。

With increasingly stringent demands for superalloys in the aerospace field, conventional composition optimization approaches have reached their performance ceiling. It has become increasingly difficult to significantly improve the performance of superalloys by adjusting the ratios of primary elements. Rare earth elements serve as important microalloying additives, and the addition of trace amounts can profoundly influence the microstructure and properties of superalloys. Industrial-scale 1 t vacuum induction melting was employed to prepare K465 master alloy ingots. The rare earth elements cerium (Ce) and yttrium (Y) were added during the smelting process to enhance the performance of this cast superalloy. Microstructural characterization was performed via optical microscopy (OM) on both the as-cast and solution-treated samples, whereas scanning electron microscopy (SEM) combined with energy-dispersive spectroscopy (EDS) was employed to analyse the microstructure systematically. The room-temperature tensile properties and high-temperature stress rupture performance after solution treatment were examined via a universal testing machine and a creep testing machine. These findings indicate that the addition of rare earth elements (Ce and Y) did not alter the phase constitution of the alloy, which is mainly composed of γ matrix phase, γ′ phase, (γ+γ′) eutectic phase, and carbides. The master alloy exhibits a room-temperature tensile strength of 887 MPa with 4.0% elongation and demonstrates high-temperature stress rupture lifetimes of 88 h and 30 min at 975 ℃/225 MPa.