U-2Nb合金等温相转变动力学  

Kinetics of Isothermal Transformation of U-2Nb Alloy

作　　者：尹嘉清 崔书山 莫文林 芮克强 何世雄 陈冬 莫川[1] 法涛[1] Yin Jiaqing;Cui Shushan;Mo Wenlin;Rui Keqiang;He Shixiong;Chen Dong;Mo Chuan;Fa Tao(Institute of Materials,China Academy of Engineering Physics,Mianyang 621907,China)

机构地区：[1]中国工程物理研究院材料研究所,四川绵阳621907

出　　处：《稀有金属材料与工程》2022年第12期4508-4518,共11页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51901210,21908210);CAEP Foundation(CX20210008)。

摘　　要：讨论了U-2Nb合金的等温转变动力学行为。通过金相定量测量,构建了其宏观动力学曲线,即时间-温度-相转变(TTT)曲线。对比之前在类似合金上的工作,发现了较大的差异。该差异主要归因于2种不同的相转变机制,即单析出反应和不连续析出反应,它们分别在较高温度(550~647℃)和较低温度范围(450~550℃)下发生。此外,讨论了通过单析出反应进行的针状α析出物在其长度方向上的生长速率。最后,运用Zener-Hillert模型模拟了单析出反应受扩散控制时的生长速率并与实验数据进行了对比。The isothermal transformation kinetics of U-2Nb alloy was investigated. Based on metallographic quantitative measurements, the general kinetics was presented with the time-temperature-transformation(TTT) diagram. Results show that considerable discrepancies are identified in comparison with previous work on similar alloys. The differences are mainly attributed to two different transformation mechanisms, namely the monotectoid and the discontinuous precipitation reactions, which are operated at higher(550~647 ℃) and lower(450~550 ℃) temperatures, respectively. In addition, the growth rate of the acicular α precipitate in its lengthening direction, which proceeds through monotectoid reaction, was discussed. Modeling of the lengthening rate was carried out with the Zener-Hillert model supposing a diffusion-controlled mechanism.

关 键 词：铀铌合金 TTT图 等温相转变 动力学 

分 类 号：TG146.8[一般工业技术—材料科学与工程]