The Investigation of Crack Crowth Rate under the Condition of Fatigue-Creep Interaction for GH132 Disc

The crack growth rates under the condition of fatigue-creep interaction at 650℃ were measured. The results of mesurement indicated that the crack growth rate was controlled by both Kmax and AK. In this case the effective stress indensity factor (Keq) is a suitable parametes describing the behaviour of crack propagation.Keq is equal to the sum of kmax and α'△k, Where α' was assumed as a parameter represented the effect of crack closure, and α' is a function of crack length.