Evaluation of Long-Term Creep Strength of Welded Joints of ASME Grades 91, 92 and 122 Type Steels

Abstract

Creep rupture data of welded joints of ASME Grades 91, 92 and 122 type steels have been collected and long-term creep rupture strength of the materials has been evaluated. Similar study was conducted by the SHC Committee in 2004 and 2005, therefore, the evaluation of the creep rupture strength was conducted with emphasis on the long-term creep rupture data obtained after the previous study, in addition to discussion of the effects of product form, welding procedure and test temperature etc. on the creep strength. Almost the same results were obtained on the welded joint of Grade 92 as the previous study, however, the master creep life equations for the welded joints of Grades 91 and 122 were lower than the previous results, especially in the case of Grade 122. Furthermore, the creep strength reduction factor obtained from 100,000 hours creep strength of welded joints and base metal was given as a function of temperature.