Dynamic fracture toughness of heavy section, narrow gap, gas tungsten arc weldments

Dynamic fracture toughness tests were performed on three, ASME SA533 Gr A Cl 2 narrow gap, gas tungsten arc weldments (minimum yield strength equals 70 ksi, 485 MPa). Linear elastic K_Id results were obtained at low temperatures while J-integral techniques were utilized to evaluate dynamic fracture toughness over the transition and upper shelf temperature ranges. Loading rates in terms of K averaged 4.41 × 10⁴ksi√(in.)/sec (4.88 × 10⁴MPa√(m)/sec). Tensile, Charpy impact and drop weight nil ductility transition (NDT) tests were also performed. The dynamic fracture toughness of both stress relieved (24 hr at 1125°F, 607°C) plus quenched and tempered SA533 Gr A Cl 2 narrow gap, gas tungsten arc weldments: (a) easily transcended the ASME specified minimum reference toughness K_IR curve, and (b) significantly exceeded the fracture toughness demonstrated by lower strength, stress relieved (3/3.5 hr at 1125°F, 607°F) SA533 Gr A Cl 2 automatic submerged arc weldments.