Crack resistance of austenitic pipes with circumferential through-wall cracks

For a monotonously increasing load the correct evaluation of the crack resistance properties of a structure is essential for safety analyses. Considerable attention has been given to the through-wall case, this is generally believed to be the controlling case with regard to complete pipe failure. The maximum load conditions for circumferential crack growth in pipes under displacement-controlled loading has been determined. The need for crack resistance curves, measured on circumferentially through-wall cracked straight pipes of austenitic stainless steel 316 L under bending, is emphasized by the limitation in the data range from small specimens and by the differences in the fracture mechanics procedures. To address these issues and to improve calculational methods a joint fracture mechanics programme is being performed by Electricité de France, Novatome and Siemens-Interatom. The working programme contains experimental and theoretical investigations on the applicability of small-specimen data to real structures.