Inconel 718合金δ相的溶解动力学  

Dissolution kinetics of δ phase in Inconel 718 alloy

作　　者：蔡大勇[1] 张伟红[1] 刘文昌[1] 姚枚[1] 

机构地区：[1]燕山大学亚稳材料科学与技术国家重点实验室,秦皇岛066004

出　　处：《中国有色金属学报》2006年第8期1349-1354,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(59971039)

摘　　要：采用X射线衍射技术测定了Inconel 718合金中δ相在980、1 000和1 020℃时的溶解动力学,并采用扫描电镜进行了组织观察。结果表明:Inconel 718合金在980、1 000和1 020℃保温过程中,δ相含量逐渐降低,经1 020℃保温2 h后,δ相可完全溶入基体;当温度为980和1 000℃时,δ相的平衡含量分别约为3%及0.6%。δ相的溶解过程可分为两个阶段,溶解初期主要表现为长针状δ相长度方向的断裂,且很快溶解断裂为短棒状及颗粒状,同时在厚度方向上尺寸逐渐减小;随着溶解过程的进行,后续的溶解过程主要为短棒状及颗粒状δ相尺寸的减小。δ相溶解动力学过程的控制环节并非Nb或Ni原子的长程扩散过程,而为δ相分解的界面反应过程。The dissolution kinetics and microstructures evolution of δ phase in Inconel 718 alloy during holding at 980, 1 000 and 1 020 ℃ were analyzed using X-ray diffraction and scanning electron microscopy. The results indicate that the dynamic equilibrium state reaches after holding at 980 ℃ for more than 30 min and at 1 000 ℃ for more than 2 h, the equilibrium contents are 3.0% and 0.6%, respectively. Nearly, the δ phase dissolves into the austenitic matrix holding at 1 020 ℃ for more than 1 h. The dissolution process of needle-like δ phase can be divided into two stages, the initial stage is mainly characterized as the fracture from long needle shape to short bars or particles. Then, the size of δ phase with short bars or particles decrease at the following stage. The dissolution models of δ phase were established and the controlling step was revealed. The whole dissolution process is governed by the interface reaction mechanism, but not by the long-distance diffusion of Nb or Ni atoms in the austenite matrix.

关 键 词：INCONEL 718合金 溶解动力学 控制环节 扩散 界面反应 

分 类 号：TG132.3[一般工业技术—材料科学与工程]