Study on low-cycle fatigue life of nickel-based superalloy GH4586 at various temperatures

Abstract The nickel-based superalloy GH4586 has been more widely used as the main material for the preparation of aerospace turbine components. However, with the development of reusable rocket engine technology, a more profound understanding of the low-cycle fatigue performance of the material under cyclic loading is required. In this study, the same specification of GH4586 used in the turbine disk of an engine is used to prepare test specimens, the fatigue performance at different strain levels of 0.5, 0.7, 0.9 and 1% is investigated, and fatigue tests are carried out at six temperatures from room temperature to 1,173 K. The fatigue σ – N curves of the material are obtained. In this study, the cyclic hardening/softening transformation mechanism of GH4586 alloy and its influence on the life of turbine components are systematically revealed through low-cycle fatigue tests with multiple temperature points (room temperature to 1,173 K) and multiple strain amplitudes (0.5–1%). The study shows that optimizing the strain amplitude below 900 K can improve the component life by more than 20%, which provides a quantitative basis for the strain–temperature coupling design of reusable rocket engine turbine.