(1. 中南大学 粉末冶金国家重点实验室，长沙 410083；
2. 株洲中航动力精密铸造有限公司，株洲 412000；
3. 中南大学 能源科学与工程学院，长沙 410083)
摘 要: 研究热处理过程中不同冷却速率对镍基高温合金中γ′相析出的影响；采用Thermal-calc热力学计算、差热分析技术，确定新型镍基高温合金的γ′相完全固溶温度；采用有限元模拟、扫描电镜分析等方法，研究端淬梯度冷却过程中合金的温度场分布及γ′相析出和演化规律。结果表明：该合金γ′相完全固溶温度为1140 ℃，在端淬梯度冷却过程中，距离喷水端越远，冷却速度越低；随着冷却速度的逐渐减小，γ′析出相的体积分数逐渐增加，γ′析出相的形貌由球形向方形逐渐转变，平均尺寸逐渐增大；时效后合金中析出大量细小三次γ′相，合金硬度增加。
关键字: 镍基高温合金；γ′相；端淬；热处理；时效
（1.State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Zhuzhou AVIC Power Investment Casting Co., Ltd, Zhuzhou 412000, China;
3.School of Energy Science and Engineering，Central South University, Changsha 410083, China）
Abstract:The effect of cooling rate during the heat treatment on the gamma prime phase precipitated in the nickel-based superalloy was studied. The solution temperature of the new type nickel-based superalloy was obtained by the thermal-calc software and differential thermal analysis (DTA) test, respectively. Based on end-quenching cooling, the effect of cooling rate on the microstructure of the nickel-based superalloy was studied. The finite element was used to simulate the temperature filed distribution. The results show that with the increase of cooling rate, gamma prime phase volume fraction increases gradually, and the morphology of gamma prime phase changes from spherical to square, the size of the precipitate phase always decreases with the increase of the cooling rate. After aging, there are a large number of 3rd gamma prime phase precipitate, inducing the increase of Vickers hardness.
Key words: nickel-based superalloy; gamma prime; end-quenching; aging; heat treatment
