抄録
When defects are detected by in-service inspections of the nuclear power plants in Japan, the allowable flaws can be evaluated in accordance with the rules on Fitness-for-Service for Nuclear Power Plants of Japan Society of Mechanical Engineers (JSME maintenance rules). Fatigue crack growth (FCG) analysis is one of the important actions for assessing the allowable flaw size. However a FCG curves for nickel base alloys in air condition is not provided in the current JSME maintenance rules. The paper summarizes the data based on the fatigue tests for the alloys and formulated FCG curves. The results show that the test temperature and stress ratio are dominant factors and the curves are the functions of these parameters. Threshold of stress intensity factor is introduced in the curves by taking into account the crack closure.
