Fracture Behavior of Dissimilar Joint by Friction Welding at Elevated Temperatures

In this study, the tensile and creep rupture behaviors of dissimilar (SA-387 Grade 91/309S or 310S/SUS-304) joint by friction welding at high temperatures were examined. The effects of temperature and applied stress on the failure locations of the dissimilar welded joints were also investigated. Creep rupture testing was conducted at 600°C and 650°C under stresses ranging from 40 to 160 MPa and 30 to 80 MPa, respectively. For all the temperatures at which the tests were conducted, the creep rupture strengths of the friction welded dissimilar metal joints were found to be lower than those of the 9Cr-1Mo-V-Nb steel base metal and dissimilar joints welded using Gas Tungsten Arc Welding (GTAW). A new type of fracture was observed for the friction welded dissimilar joints.