3542 Effect of grain size on properties of fatigue crack growth of Inconel 718 at elevated temperature

Abstract

Rotating bending fatigue tests were carried out for Inconel 718 at 500℃ in order to investigate the effect of grain size on the propagation behavior of a fatigue crack. Fatigue strength was higher in fine grained material than in coarse grained one. However, the resistance to crank growth was higher in coarse grained material than in fine grained one. The difference in fatigue strength in both materials can be explained by the retardation of small crack growth and the crack growth resistance.