晶界一次γ'相对GH4720Li合金晶粒长大行为的影响

As-forged GH4720Li superalloy was isothermally heat treated at different temperatures for different time, and the grain size, volume fraction and particle size of primary γ' phase were quantitatively characterized. The dissolution and grain growth behavior of grain boundary primary γ' phase of the as-forged GH4720Li superalloy during heating at 1050-1160℃ were studied, and the influence of grain boundary primary γ' phase on the grain growth behavior of the superalloy was analyzed. The results show that when the size of the grain boundary primary γ' phase is less than 3. 5 μm, the pinning effect on grain boundary is weakened, which leads the grain size of the superalloy to grow obviously. When the heat treatment temperature is higher than 1150℃, the grain grows abnormally due to the large amount of dissolution of the strengthened phase. The grain growth law of the superalloy with different sizes of grain boundary primary γ' phases is analyzed from the kinetic point of view, the kinetic model to characterize the grain growth behavior of the GH4720Li superalloy is established by using Arrhenius equation, and the prediction accuracy of the model is evaluated by the experiment results.