(1. 中南大學 粉末冶金國家重點實驗室，長沙 410083；
2. 株洲中航動力精密鑄造有限公司，株洲 412000；
3. 中南大學 能源科學與工程學院，長沙 410083)
摘 要: 研究熱處理過程中不同冷卻速率對鎳基高溫合金中γ′相析出的影響；采用Thermal-calc熱力學計算、差熱分析技術，確定新型鎳基高溫合金的γ′相完全固溶溫度；采用有限元模擬、掃描電鏡分析等方法，研究端淬梯度冷卻過程中合金的溫度場分布及γ′相析出和演化規(guī)律。結果表明：該合金γ′相完全固溶溫度為1140 ℃，在端淬梯度冷卻過程中，距離噴水端越遠，冷卻速度越低；隨著冷卻速度的逐漸減小，γ′析出相的體積分數(shù)逐漸增加，γ′析出相的形貌由球形向方形逐漸轉(zhuǎn)變，平均尺寸逐漸增大；時效后合金中析出大量細小三次γ′相，合金硬度增加。
關鍵字: 鎳基高溫合金；γ′相；端淬；熱處理；時效
（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
