(1. 中航工业沈阳黎明航空发动机(集团)有限责任公司，沈阳 110043；
2. 中国科学院 金属研究所，沈阳 110016；
3. 中国人民解放军驻黎明公司军代表室，沈阳 110043)
摘 要: 通过Gleeble热模拟实验，测绘Ti-55钛合金的连续冷却转变曲线(CCT图)。结果表明：当冷速由0.1 ℃/s加快到150 ℃/s时，Ti-55钛合金中主要发生β→α与β→α′的相转变过程，其中β→α′转变开始的临界冷速为 5 ℃/s左右，Ti-55钛合金中马氏体转变开始温度为855 ℃，转变结束温度为818 ℃。
关键字: 连续冷却转变曲线；马氏体相变；Ti-55钛合金
microstructure evolution of Ti-55 alloy
（1. AVIC Shenyang Liming Aero-engine (Group) Corporation, Ltd., Shenyang 110043, China;
2. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
3. Office of Chinese Peoples Liberation Army in Shenyang Liming Aero-engine (Group) Corporation, Ltd., Shenyang 110043, China）
Abstract:The continuous cooling transformation (CCT) diagram of Ti-55 titanium alloy was plotted and the microstructure evolution of this alloy during cooling was discussed. The results show that when the cooling rate increases from 0.1 ℃/s to 150 ℃/s, there mainly exist two phase transformations, β→α and β→α′. It is also shown that the critical cooling rate of the beginning of β→α′ phase transformation is 5 ℃/s, the starting temperature of martensitic transformation is about 855 ℃ and the finishing temperature is about 818 ℃.
Key words: continuous cooling transformation diagram; martensitic transformation; Ti-55 alloy
