中文摘要：

对离心喷射沉积（CSD）IN718合金涡轮盘沿厚度方向Nb元素的含量、热处理制度、凝固态成分偏析区的体积分数、δ及γ相中各元素含量及其分配量进行了研究。结果表明：尽管在CSD成型合金中Nb的偏析比较小，但使用标准热处理制度尚不能使其均匀化：采用1040℃，6h固溶均匀化处理可使Nb的偏析消除，并在该温度下经21h处理可在盘厚截面上获得Nb的均匀分布；将完全均匀化的试样分别经910℃，2h，4h，6h，8h时效，在δ相（γ相）中元素Ni，Nb和Ti的含量及其分配量逐渐增加（减少），与之相对应，元素Cr和Fe的含量及其分配量逐渐减少（增加），采用亚点阵元素浓度测算法，能合理确定时效过程中δ及γ相中各元素的含量及其分配量的变化。

英文摘要：

Distribution of Nb along turbine ring thickness, heat-treatment procedures, volume fraction of Nb segregation regions, elemental concentration and partition value of δ and γ phases were investigated in CSD-formed IN718 alloy. Experimental results showed that the segregation ratio of Nb in CSD-formed IN718 alloy was relatively smaller than that in the conventional as cast IN 718 alloy. The segregation of Nb along the ring thickness still existed after the standard heat-treatment performed on the CSD samples. The phenomenon of Nb-segregation in the CSD-formed IN718 samples disappeared after solution treated at 1040℃ for 6 h. The elemental in homogeneity of Nb was basically eliminated along the turbine ring thickness of the CSD-formed IN718 after solution treated at 1040℃ for 21 h. The CSD-formed IN718 samples solution treated for 21 h were aged at 910℃ for 2 h, 4 h, 6 h and 8 h, respectively in order to observe the change in elemental concentration and the partition value of δ and γ phases. The elemental concentrations and partitions value of Ni, Nb and Ti for δ（γ） phase gradually increased （decreased）; while that of Cr, Fe and Mo for δ（γ） phase gradually decreased （increased） with the increase of ageing time. The elemental concentration and partition value in δ and γ phase for aged CSD samples were determined by using the published elemental concentration determination method of sublattices of ordered phases in Ni-base superalloys.