V对镍基高温合金组织及蠕变性能的影响

Effect of Element V on Microstructure and Creep Property of Nickel-Based Superalloy

通过组织形貌观察及蠕变性能测试,研究元素V对一种镍基高温合金组织及性能的影响。结果表明:含有较高Ta、Hf成分的镍基柱状晶高温合金,当加入0.58%V后,铸态合金中的碳化物由细长条状转变为颗粒状;热处理后不含V合金中的长条形碳化物溶解转变为线性分布的颗粒状碳化物,而含V合金中的碳化物发生溶解,尺寸减小,同时γ′相数量增加,促进了MC型碳化物的分解速度,在900℃长时效2 000 h后开始出现针状TCP相组织;元素V的加入降低了合金的蠕变性能。

The effect of element V on the microstructure and creep property of the nickel-based superalloy DZ125 was investigated by the observation of microstructure and the test of creep properties. The results show that for the columnar crystal nickel-based superalloys containing higher Ta and Hfelements, when the element V of 0.58% is added, the shape of the precipitated carbides in the as-cast alloy transforms from the slender strips to the particles. After being heat-treated, the slender strip carbides in the alloy free of element V- are dissolved and transformed into the linearly distributed granular particles, while in the alloy containing element V, the carbides are dissolved and their sizes are decreased, furthermore, the number of γ′ phase is increased, and the decomposition rate of MC carbides is promoted. Moreover, a needle-like TCP phase began to appear in the alloy containing V after a long term aging at 900℃ for 2 000 h. The addition of element V reduces the creep performance of the alloy.