Reusable Turbine Material GH4586: Stochastic Analysis and Reliability Assessment of Low-Cycle Fatigue Life Parameters at Multiple Temperatures

Turbines, crucial in reusable rocket engines, benefit significantly from precise fatigue life forecasting in their force-thermal cyclic loading conditions. Further, low-cycle fatigue life predictions can be random due to uncertainties in material properties. This study aims to analyze the probabilistic low-cycle fatigue life of GH4586 under different temperature. Mechanical and thermal tests were carried out for the temperatures between 87 K and 1173 K. Random distributions of low-cycle fatigue parameters were obtained using various methods. The cyclic life reliability of a reusable rocket engine turbine rotor blisk was analyzed using stochastic low-cycle fatigue parameters. Mitchell's method had a higher prediction accuracy when the reliability was greater than 0.8. Sensitivity analysis shows the significant impact of GH4586 fatigue parameters on cyclic life reliability. Sensitivity coefficients of strength coefficient and ductility coefficient are 32.73% and 27.06%, respectively. These findings provide valuable insights that inform the design of turbines and enhance their reliability.