Estimation of C-t for weld cracks including HAZ softening region

Abstract

C-t is an important parameter in predicting creep crack growth life from the small-scale creep stage to the extensive steady state creep stage. In this paper, weld interface and non-interface creep cracks for compact tension (CT) specimens with heat-affected zone (HAZ) were studied by finite element method (FEM) to systematically research the estimation method of C-t for weld creep cracks. Simulation results showed that C-t of weld interface cracks could be estimated by Yoon's method. For weld non-interface cracks, C-t under the small-scale and transition creep stages could be exactly estimated by a proposed method. The accuracy of the proposed method was not affected by HAZ, but Yoon's method was slightly affected by HAZ.