Comparison of the creep and damage failure prediction of the new, service-aged and repaired thick-Walled circumferential CrMoV pipe Welds using material properties at 640 deg C

摘要

Finite element creep and damage analyses were performed for a series of new, service-aged, folly repaired and partially repaired, circumferential welds in CrMoV main steam pipes, under an internal pressure and a uniform axial stress, using simplified axisymmetric models. The material properties used were those of a 1/2Cr1/2Mo1/4V: 21/4CrlMo weldment at 640 deg C. Failiure were obtained using damage modelling and these were obtained using damage modelling and these situations were also investigated. Comparison of the various failure predictions allows the effects of the differences in the relative properties of the constituents of the weld, the geometry and system loading, to be identified. The information is useful for assessing the performance of practical service-aged/repaired welds in power plants pipework.