Bimetallic/narrow gap welded pipe fracture tests under cyclic bending load
In order to study the crack growth and cyclic tearing instability, which are required for realistic assessment of Leak Before Break applicability, experimental investigations were carried out on five numbers of narrow gap welded SA 312 Gr. TP 304LN stainless steel straight pipes of 324 mm outer diameter under quasi-cyclic loading. The pipe specimens which were tested under load control failed by ductile tearing till sufficient crack length was reached followed by sudden rupture and collapse. For load values corresponding to 70%, 80%, 85% and 90% of the static load carrying capacity of the pipe, the number of cycles to final failure under quasi-cyclic loading were 120, 72, 41 and 21 respectively.
