Evaluation of fracture resistance of AISI type 316LN stainless steel base and welded pipes with circumferential through-wall crack

Highlights: • The J-R curves of 316LN SS base and weld pipes are compared with C(T) specimens. • The effect of initial crack angle on weld pipe J-R curve is negligible. • In weld pipes, the crack has deviated into interface/base material due to extensive plastic deformation in the interface. • Crack initiation occurs much earlier than maximum bending moment. -- Abstract: Fracture resistance of 316LN SS base and welded straight pipes with circumferential through-wall cracks has been evaluated. The pipe J-R curves have been determined using existing experimental methods and analytical expressions available in literature. The J-R curves of 88.9 mm OD pipe and pipe welds have been compared with the J-R curves obtained from C(T) specimen tests. The results indicate that the C(T) specimen data is not suitable for fracture assessment of pipes due to difference in constraint level and the fracture resistance of the base pipe is inferior to welded pipe. Further, the limit load analyses based on expressions available in literature reveals that the initiation and crack propagation are observed prior to the maximum bending moment.