【摘要】 通过热力学计算，建立了Ｃｒ，Ｍｏ及 Ｎｂ与ＩＮ７１８合金的赝二元相图以及Ｃｒ－Ｆｅ－ＩＮ７１８赝三元等温截面图．研究了ＩＮ７１８合金中α－Ｃｒ相析出条件和化学成分对α—Ｃｒ相析出温度及析出量的影响．确定了α－Ｃｒ相析出的临界成分和不同成分条件下α－Ｃｒ相开始析出温度及析出量，同时得出了Ｃｒ，Ｍｏ和 Ｎｂ含量与α－Ｃｒ相开始析出温度和析出量的关系式．利用Ｘ射线衍射对萃取相的分析及选择性浸蚀方法，验证并显尔了α—Ｃｒ相在ＩＮ７１８合金中的存在和分布．更多还原

【Abstract】 The precipitation behavior of α-Cr phase in IN718 alloy was studied by thermodynamic calculation and microstructural analyses. Thermodynamic calculation shows that the contents of Cr, Mo, and Nb have an important effect on the precipitation behavior and precipitation temperature of α- Cr phase. The Cr-IN718, Mo-IN718, Nb-IN718 pseudo-binary phase diagrams and the Cr-Pe-IN718 pseudo-ternary phase diagram at 650 ℃ were calculated, the critical composition, the precipitation temperature and the quantity of α-Cr phase were obtained. Furthermore, the precipitation of α-Cr phase in IN718 was identified by XRD and SEM.更多还原