Crack propagation behavior by thermal fatigue around DSCu/SS316 HIP bonded interface

Hot Isostatic Pressing bonded (HIPed) structure of DSCu/SS316 is proposed for the first wall (FW) of ITER. In this report, the thermal fatigue crack propagation behavior around HIPed interface is investigated with DSCu/SS316 HIPed plate as a specimen which has an initial crack on DSCu side. In addition, numerical analysis is carried out to clarify the mechanism of the interfacial crack propagation and to evaluate crack propagation rate with fracture mechanics. It is concluded that the crack which was propagated very close to HIPed interface did not penetrate into SS316 and changed its propagation direction from perpendicular to parallel to HIPed interface. The interfacial crack is propagated by residual stress in combined mode.