Some of the Japanese Fossil power plants have been operating more than 200 thousand hours, and several kinds of damage was observed. So the assessment of residual life of these aged components has became important increasingly. In order to improve the accuracy of residual life prediction, several new techniques have been developed. In this paper, recent three kinds of techniques in IHI are introduced as follows. -For the creep-fatigue damage in header tube stub, Y-piece of main steam pipe and pipe stub, the assessment method based on the behavior of small cracks was developed. -For the creep damage in early stage of life, which could not be detected before, the assessment method based on the change of carbides components was developed. -For the assessment of creep damage in tube, the creep rupture tests of sampled pieces have performed until now. the alternative non-destructive method based on the creep deformation was proposed to reduce the assessment cost and to improve the accuracy.
展开▼
