An experimental and theoretical consideration of the effect of prior creep damage on the heat affected zone fracture toughness of CrMoV steel

Material encompassing the heat affected zone has been removed from a region of a manual metal arc weldment in a CrMoV steel. This zone contained creep cavities on grain boundaries oriented normal to the direction of the maximum principal stress arising from the stress relief heat treatment. Fracture toughness tests using reconstituted Charpy geometry specimens with side grooves were undertaken at temperatures of 150 and 350 °C to assess the effect of the creep cavitation on the measured fracture toughness. The results are compared and discussed with respect to the predictions of a theoretical two-dimensional model.