一种新型第三代镍基粉末高温合金亚固溶热处理调控 γ'相分布的研究

This research investigated the influence of sub-solvus heat treatment processes on the γ' phase microstructure of a novel third-generation nickel-based powder superalloy FGH4113A(WZ-A3). The temperature, soaking time, cooling rate of sub-solvus heat treatment, and the effects of super-solvus+sub-solvus, sub-solvus+sub-solvus on γ' phase were mainly explored. The results indicate that: the volume fraction of γ' phase is inversely proportional to the sub-solvus heat treatment temperature. The tendency of γ' phase dissolving back into γ phase is inversely proportional to the size, and the quantity is inversely proportional to the soaking time. The size of grain boundary γ' phase increases with the increase of soaking time, and the overall volume fraction of γ' phase does not change significantly with the increase of soaking time. A fast cooling rate can re-precipitate an intergranular fine unimodal γ' phase structure. A slower cooling rate can re-precipitate intergranular multimodal γ' phase structure. The size of the reprecipitated γ' phase is inversely proportional to the cooling rate. The microstructure after super-solvus+sub-solvus heat treatment is mainly affected by the temperature and cooling rate of the sub-solvus heat treatment. The lower the temperature, the more rectangular γ' phases are in the grain. The small size spherical γ' phase will be coarsened into a rectangle shape at high temperature, which is affected by the absolute value of the mismatch degree of the γ/γ' phase. The γ' phase microstructure of sub-solvus+sub-solvus heat treatment is greatly affected by temperature.