Abstract
In this study, tensile and creep rupture properties of dissimilar welded joints (9Cr-1Mo-V-Nb/Inconel82/SUS304) were examined at elevated temperatures. Effect of temperatures and stresses on the failure location of the dissimilar welded joint was also investigated. Creep rupture tests were conducted at three temperatures: 823, 873, and 923K, and in stress ranges from 160 to 240 MPa, 80 to 160 MPa, and 40 to 80 MPa, respectively. The results of the elevated temperature tensile tests on the dissimilar welded joint showed that the location of fracture changes dependent on the tensile strength of base metal. The creep rupture strength of the dissimilar welded joint was lower than that of the 9Cr-1Mo-V-Nb steel base metal at all temperatures. In addition, the differences in creep strength between the dissimilar welded joint and base metal were increased as the temperature increased. The fracture type observed after long-term creep rupture tests on the dissimilar welded joint was shifted from the Type V and Type VII fracture at lower temperatures to the Type IV fracture at higher temperatures. It can be predicted that the fracture type of the 100,000 h creep rupture at 823K and 873K for dissimilar welded joint is Type IV fracture of 9Cr-1Mo-V-Nb steel.
