Fracture toughness testing of weld metal: Results of a European round robin

This paper presents the results of a collaborative project on fracture mechanics toughness resting of weldments, carried out by twelve European laboratories. Each collaborator was asked to measure the fracture toughness of a steel weldment, notched in the weld metal. Tests were carried out at two temperatures, using three test geometries, in accordance with a standard procedure. Results are reported in terms of the effect of temperature and specimen geometry on fracture toughness (mean value and standard deviation), the extent of inter-laboratory reproducibility of results and the effect of ''invalid'' results on the measured value of fracture toughness. As a result of the study, it is recommended that a number of the current validity criteria in BS7448:Part 1 should be relaxed in Part 2 when applied to tests on weld metal.