利用OM、SEM及热力学计算等方法研究了GH4151合金在热处理过程中的组织演变行为。结果表明，高合金化导致合金的铸态组织复杂，包括Laves相、γ/γ′共晶、η相等低熔点相。由于各析出相的初熔温度不同，制定了三段式热处理，有效地消除了合金中的有害相。铸态GH4151合金中偏析元素Nb和Ti含量对低熔点相初熔温度的影响较大，Mo含量的影响相对较低，W含量的影响不明显。降低Ti含量，提高Nb、Mo含量可降低η相的初熔温度；提高Ti、Mo含量，降低Nb含量可降低Laves相的初熔温度。高含量的γ′相形成元素导致γ′相的组织演变行为具有冷却速率敏感性。15℃/min是GH4151合金中γ′相发生不规则生长的临界冷却速率。与低含量γ′相形成元素的合金相比，GH4151合金冷却速率高于15℃/min时，γ′相尺寸更大；冷却速率低于15℃/min时，γ′相不规则程度更高。高合金化的特点导致GH4151合金呈现复杂的组织演变行为。

Designing high-performance aeroengine is important for development in the aviation industry. One of the key components is turbine disk material that can operate at 800^oC. Among various methods for strengthening alloys, increasing the alloying degree is important, and GH4151 is one of the typical alloys with a high alloying degree. It comprises a large number of refractory metal elements and γ'-forming elements. OM, SEM, and JMatPro software were used to study the sensitivity of GH4151 microstructure evolution during heat treatment processes. The results show that a high alloying degree produces a complex microstructure with low-melting phases, such as Laves, γ/γ′ eutectic, and η phases. Due to the difference in incipient melting temperature of each precipitated phase, a three-stage heat treatment was developed to effectively eliminate the harmful phases in the alloy. The contents of segregation elements Nb and Ti in the as-cast GH4151 alloy have an obvious influence on the incipient melting temperature, whereas the effect of Mo content is relatively slight, and that of W content is not obvious. Decreasing Ti content while increasing Nb and Mo contents could reduce the incipient melting temperature of the η phase. Furthermore, increasing Ti and Mo contents while decreasing Nb content could reduce the incipient melting temperature of Laves phase. A large amount of γ'-forming elements contributes to the cooling rate sensitivity of γ′ phase evolution. 15^oC/min is the critical value for the irregular growth of the γ' phase in the GH4151 alloy. When compared to alloys with low γ′-forming elements content, the γ′ phase in GH4151 alloy has a larger size when the cooling rate is > 15^oC/min, and exhibits an irregular shape when the cooling rate is < 15^oC/min. Thus, a high alloying degree contributes to the complex and sensitive microstructure evolution behavior of GH4151 alloy.