Creep of welded pipes

Abstract

Creep continuum damage mechanics analyses and peak stationary state stresses in the base, heat-affected zone and weld materials of a welded joint in a pipe were used to obtain failure times. The properties related to a1/2Cr1/2Mo1/4V:21/4Cr1Mo welded joint were used in the analyses. Similar analyses were performed on cross-weld specimens. The predictions indicate that, for moderate systems loading, using the mean diameter hoop stress in conjunction with cross-weld creep test data would result in safe failure predictions for the welded pipes. The results also indicate that reasonably accurate predictions of safety factors would be obtained using peak stationary state stresses, thus eliminating the need for the more complex and time-consuming creep continuum damage mechanics analyses.