热处理作为影响高温合金显微组织的重要手段，在高温合金的研究中占有重要的地位。了解合金显微组织演变有助于优化合金成分、显微组织和加工工艺，进而为研发并设计新一代高性能高温合金提供理论指导。本文利用JMatPro热力学模拟计算软件对不同硼含量合金的平衡相图、凝固路径等特性进行了计算，结合差示扫描量热法确定了合金的相变温度点，依据合金的凝固特征温度制定了六种热处理工艺，对合金进行了不同工艺的热处理，并对铸态组织和热处理理后的组织进行了分析研究。主要研究了热处理对合金的枝晶组织、γ/γ′共晶组织、γ′相形貌与尺寸、碳/硼化物、微孔及γ/γ′两相晶格错配度的影响，得到以下主要结论： （1）合金在600℃~1500℃之间的模拟析出相为L相、γ相、γ′相、碳化物相、M3B2硼化物相及TCP相等；随着B元素含量的增加，TCP相的析出量和析出温度呈降低态势，表明B元素能够抑制高温合金中的TCP有害相；合金的特征温度也随B含量的增加逐渐下降，合金热力学计算结果与DSC实验结果接近，表明了模拟计算结果的准确性。在B3合金中σ相、μ相的孕育期较长，但在TTT曲线中的鼻尖温度较低，合金在1070℃及以上温度服役时最长经过30.9 h或在1140℃最长经过7.3 h的孕育期合金内部会逐渐析出TCP有害相，因此合金的时效处理制度可设为1080℃/6h+870℃/24h。 （2）B0和B1合金分别在T6(1310℃)、T5(1305℃)的热处理制度下合金的枝晶花样消除均比较完整。B1合金经过T5(1305℃)制度热处理后各元素的Mapping分析发现，合金经过热处理后的元素均匀化效果非常显著。B2、B3合金经过T1(1285℃)、T2(1290℃)热处理制度处理后枝晶花样消除非常明显。升高热处理固溶温度，B2、B3合金分别在T4(1300℃)、T3(1295℃)热处理制度处理下，合金的枝晶组织基本消除，均匀化效果更加显著。 （3）经过热处理后，合金中的碳化物形貌由铸态的汉字状转变为了颗粒状和细杆状，随着固溶处理温度的增加碳化物的尺寸逐渐减小。对碳化物进行EDS元素能谱分析，发现合金中的碳化物相主要为富含Ta、Hf的MC型碳化物，说明合金中的碳化物类型并未发生转变。 （4）合金经过热处理处理后γ′相形貌开始转变为规则的立方体形貌；B0、B1合金的γ′相尺寸随着固溶温度的升高逐渐增大，B0和B1合金的γ′相尺寸最大分别达到了0.355 μm和0.351 μm；B2、B3合金的γ′相尺寸随着固溶温度的升高呈先增大后减小的变化趋势，两者在T2(1290℃)展现出了最大的尺寸，最大分别达到了0.438 μm和 0.398 μm，在之后的冷却过程中析出的γ′相形貌均表现为规则的立方体形貌。

As an important means to influence the microstructure of superalloys, heat treatment plays an important role in the research of superalloys.Understanding the microstructural evolution of alloys is helpful to optimize the composition, microstructures and processing technology of alloys, thus providing theoretical guidance for the development and design of a new generation of high performance superalloys.In this paper, the equilibrium phase diagrams and solidification paths of alloys with different boron content are calculated by JMatPro thermodynamic simulation software.The phase transformation temperature of the alloy was determined by differential scanning calorimetry. Six heat treatment processes were developed according to the solidification characteristic temperature of the alloy. The heat treatment of the alloy was carried out in different processes. The as-cast structure and the structure after heat treatment were researched.The effects of heat treatment on dendritic structure, γ/γ′ eutectic structure, morphology and size of γ′ phase, carbon/boride, micropore and mismatch degree of γ/γ′ phase lattice of the alloy were studied. (1) The precipitation phases of the alloy are L phase, γ phase, γ′ phase, carbide phase, M3B2 boride phase and TCP equal between 600 and 1500℃. With the increase of B element content, the precipitation amount and precipitation temperature of TCP phase decrease, which indicates that B element can inhibit the harmful TCP phase in the superalloy. The characteristic temperature of the alloy decreases gradually with the increase of B element content, and the thermodynamic calculation results of the alloy show that B element can inhibit the harmful TCP phase in the superalloy. It is close to the DSC experimental results and shows the accuracy of the simulation results. The incubation period of σ and μ phases in B3 alloy is longer, but the nose tip temperature in TTT curve is lower. TCP harmful phases will gradually precipitate in the alloy during the incubation period up to 30.9 h at 1070℃ or 7.3 h at 1140℃. Therefore, the ageing treatment system of the alloy can be set at 1080℃/6 h+870℃/24 h. (2) The dendrite patterns of B0 and B1 alloys were eliminated completely under the heat treatment systems of T6 (1310℃) and T5 (1305℃) respectively. Mapping analysis of elements in B1 alloy after T5 (1305℃) heat treatment shows that the homogenization effect of elements in B1 alloy is remarkable. The dendrite pattern of B2 and B3 alloys is eliminated obviously after heat treatment of T1 (1285℃) and T2 (1290℃). With the increase of solution temperature, the dendrite structure of B2 and B3 alloys is basically eliminated and the homogenization effect is more remarkable under the treatment of T4 (1300℃) and T3 (1295℃) respectively. (3) After heat treatment, the morphology of the carbide in the alloy changes from the as-cast Chinese character to the granular shape and the thin rod shape, and the carbide size decreases with the increase of the solution treatment temperature. The EDS elemental energy spectrum analysis of the carbides showed that the carbide phase in the alloy is mainly MC-type carbides rich in Ta and Hf, indicating that the carbide type in the alloy did not change. (4) After heat treatment, the morphology of γ′phase begins to change into regular cubic morphology; the size of γ′phase of B0 and B1 alloys increases gradually with the increase of solution temperature, and the maximum size of γ′ phase of B0 and B1 alloys reaches 0.355 and 0.351 μm respectively. The γ' phase size of B2 and B3 alloys increased and then decreased with the increase of solid solution temperature. The two exhibited the largest size at T2 (1290℃), reaching a maximum of 0.438 μm and 0.398 μm respectively. The γ' phase morphology precipitated during the subsequent cooling process is represented by a regular cubic morphology.