High-temperature short-term tensile test and creep rupture strength prediction of the T92/TP347H dissimilar steel weld joints

After short-term tensile test at 848–923 K, microstructures, fractographies and fractural mechanisms of the T92/TP347H dissimilar steel weld joints were studied. An equation of the creep rupture strength related to the short-term tensile strength of the joints was firstly derived based on the Goldenberg model [1]. In the high-temperature tensile process, the fracture location of the joints is all in the T92 side fine grained heat affected zone (FGHAZ); however, the fracture mechanism of the joints is changed from a mixed mode (normal plus shear) to a shear mode as the testing temperature risen, which was explained in terms of the stress tri-axiality theory. Moreover, an equation of the creep rupture strength of the weld joints was derived, and then the creep rupture strength of the joints was doped out, σ105873=49.0MPa. It indicates that the joints have a high reliability when used in the USC power units.

► High-temperature tensile structures and fracture mechanisms of the T92/TP347H joints.
► Stress tri-axiality theory used to discuss the tensile process of the joints.
► Creep rupture strength of the joints was doped out, σ105873=49.0MPa.