【摘要】 通过ＩＮＣＯＮＥＬ７１８（ＧＨ１６９）合金中主要强化元素Ｎｂ、Ｔｉ、Ａｌ的调整获得γ″＋γ′相的复合析出，使其组织稳定性得以提高，突破了６５０℃的使用温度上限。在γ″和γ′复合析出强化的新型镍基合金中γ″在高温时聚集长大速率降低，γ″→δ转变延迟，高温组织稳定性提高，并且其拉伸、持久和蠕变性能都比ＩＮＣＯＮＥＬ７１８原型合金为优。新型合金成分范围基本上仍保持ＩＮＣＯＮＥＬ７１８合金的基础，当Ｎｂ含量在５０％～５３％（质量分数）时，Ａｌ＋Ｔｉ＋Ｎｂ的总量应控制为６５％～７５％（原子分数），且（Ａｌ＋Ｔｉ）／Ｎｂ的原子含量比在１１～１４之间。更多还原

【Abstract】 A peculiar form of combined precipitates of γ″ and γ′ is developed by modifying the main strengthening elements of Nb,Ti and Al in order to increase high thermal structure stability to be used beyond the ceiling temperature of 650℃. Detail TEM and mechanical property studies have shown that not only thermal structure stability was improved since the coarsening rate of γ″ in modified alloy 718 was decreased and the phase transformation of γ″→δ was delayed, but also the mechanical properites, such as tensile properties,stress rupture life and creep properties were superior than conventional IN 718. The modification of main strengthening elements has been suggested as follows:Nb:50%～53%(mass fraction); Nb+Ti+Al:65%～75%(atom fraction); (Al+Ti)/Nb:11～14 in atomic ratio.更多还原