Ductile-to-Brittle Transition in Steel Weldments for Arctic Structures

摘要

The report summarizes the work performed in support of the development of fracture criteria for steel weldments in arctic structures. The ductile-to-brittle transition behavior of a shielded metal-arc weld, typical of steel weldments in arctic structures, has been studied. Fracture toughness, Charpy V-notch impact energy, and tensile properties have been measured as a function of temperature throughout the ductile-to-brittle transition range. The effect of geometric dimensions on fracture toughness has been studied for three geometries of single-edge-notch-bend (SENB) specimens. The fracture surfaces of broken specimens have been characterized by scanning electron microscopy (SEM). The microstructure of the multiple-pass weldment has been studied by optical microscopy. The mechanical properties of the steel weldment have been compared to the base metal, an ABS grade EH36 steel in normalized condition.