In order to propose the fatigue crack growth rate curves for nickel base alloy, fatigue crack growth rates were measured by fatigue crack growth tests. Compact Tension specimens with a thickness of 1 inch made by JIS-NCF600 were used in simulated BWR environment. As a result of this study, the threshold stress intensity factor range (ΔK_<th>) for JIS-NCF600 was estimated at 3.0 MPa√m. The fatigue crack growth rate curves for JIS-NCF600 in BWR environment were proposed.
