Abstract: This paper summarizes the development history and application performance research results of domestic and foreign scholars on anti-oxidation low expansion In783 alloy. The resistance of stress accelerated grain boundary oxidation （SAGBO） performance of the alloy has been greatly improved by β phase precipitation， which makes the alloy exhibit low thermal expansion coefficient （CTE）， good oxidation resistance and comprehensive mechanical performance below 750 ℃. It is widely used in the manufacturing of sealing components for aviation engines and bolts for ultra supercritical steam turbines. The research results of domestic scholars on the microstructure and properties of GH6783 alloy （Chinese grade GH6783） during domestication process are summarized. After long-term service， needle shaped Ni₅Al₃ phase precipitates inside the β phase， significantly deteriorating the plasticity of GH6783 alloy at 650 ℃. The anatomy analysis of the microstructure of currently imported In783 alloy rods reveals that the uniformity of the β phase microstructure was far worse than the results reported in the literature. It not only contains a large mass of primary β microstructure， but also has a suspected needle-like Ni₅Al₃ phase inside the β phase. Daye Special Steel Co.， Ltd. has conducted systematic research on the double vacuum smelting， electrode annealing， high-temperature homogenization and forging process of GH6783 alloy， and achieved significant results， with a significant improvement in the uniformity of microstructure and mechanical properties of GH6783 rod material. Regarding to serious anisotropy high tensile plasticity at 650°C of GH6783 alloys rods produced at home and abroad， it is found that this is related to the orientation of the γ' phase， and the relevant research work is being further conducted.Finally， the application prospects and future research directions of GH6783 alloy are discussed to meet the major national demands and the demand for advanced high-temperature alloy materials for sustainable social development.

Key words: GH6783, In783, β - phase, Oxidation Resistant, Low Epansion Superalloy

摘要： 总结了国内外学者对抗氧化型低膨胀In783合金的开发历史和应用性能研究成果，通过β相的析出大幅度改善了合金的抗SAGBO性能，使合金在750 ℃以下具有低的热膨胀系数、良好的抗氧化性和综合力学性能，被广泛应用于制造航空发动机封严零部件和超超临界汽轮机螺栓。总结了国内学者对In783合金国产化（国内牌号GH6783）过程中组织和性能研究成果，长期服役后，在β相内部析出针状的Ni₅Al₃相导致合金650 ℃的塑性大幅度恶化。对目前进口的In783合金棒材组织进行解剖发现，β相组织均匀性远差于文献报道结果，不仅含有超大块的初生β相组织，而且β相内部存在疑似针状的Ni₅Al₃相。大冶特殊钢有限公司对GH6783合金的双真空熔炼、电极退火、高温均质化及锻造工艺进行了系统性研究，成效显著，棒材微观组织和力学性能均匀性大幅度提升。针对目前国内外生产的棒材的650 ℃高拉塑性均存在严重的各向异性现象，经分析发现与γ’相的取向有关，相关研究工作正在进一步开展中。最后对GH6783合金的应用前景及未来研究方向进行了展望，以满足国家重大需求和社会可持续发展对先进高温合金材料的需求。

关键词: GH6783, In783, β相, 抗氧化, 低膨胀高温合金