Evaluation of the influences of the stress ratio, temperatures, and local microstructure on small fatigue crack propagation behavior of the FGH96 superalloy

Here, the influences of the stress ratios, temperatures, and local microstructure on the propagation behavior of small fatigue crack for FGH96 superalloy are quantitatively investigated. Following an increase in the stress ratio and temperature, the small fatigue crack growth rates increased. The influences of the local microstructure on the restrained ability for small fatigue crack propagation are analyzed, and the critical stress range of small fatigue crack propagation for the FGH96 superalloy at different stress ratios is proposed based on an amendatory-three-dimensional Kitagawa–Takahashi diagram. These results can aid in the fatigue damage tolerance design of FGH96 superalloy components.