Abstract:Aiming at the high-temperature fatigue failure risk of GH4710 alloy turbine disks for aero-engines, the fatigue crack growth behavior of the alloy at 750℃, 815℃ and 850℃ was systematically studied, the temperature influence mechanism was revealed, and a temperature-dependent model was established. The results show that grain boundary oxidation weakening is the dominant factor for accelerated crack growth at high temperatures. When the temperature increases from 750℃ to 850℃, the fatigue crack growth rate of the alloy increases significantly, the fatigue life decreases by 74.7%, and the fracture mechanism transforms from transgranular dominance to intergranular dominance. The range of 815~850 ℃ is the critical mutation temperature range for fatigue performance, and below this temperature, the alloy has a wider stress intensity factor range ( ΔK) and better crack growth resistance. Based on the Paris equation, an Arrhenius-type temperature correction term was introduced to establish the model: da/dN=9.783×10^(-7)×exp?(-3557.068/T) (ΔK)^3.183 (T is absolute temperature, K). Within the range of ΔK =20~65 MPa·m?·?, the error between the model predictions and experimental data is less than 10%, which can accurately characterize the fatigue crack growth behavior of the alloy in the temperature range of 750~850℃. This study provides theoretical support for the damage tolerance design, high-temperature service life prediction and critical temperature early warning of GH4710 alloy turbine disks.