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As interest in oil & gas exploration and production in Arctic regions increases, there is a need to ensure that welded infrastructure possesses adequate structural integrity to safely meet the demanding service environments associated with extreme low temperatures, wind and wave loading, icing, and potential ice flows. Significant research has already been carried out to develop base materials for Arctic conditions that have led to suitable plate and pipe products being commercially available. However, performance of weld consumables in Arctic environments remains an active area of research and development.

While current commercially available weld consumables provide good strength, ductility and fracture toughness for sub-tropical and temperate environments, it is less certain that these consumables will provide consistent properties in severe Arctic environments where temperatures can reach -60oC. Characterization of properties that are achievable in weld consumables produced using conventional offshore structural fabrication practice is limited for temperatures common in Arctic service. Efforts are underway at some consumable manufacturers to develop weld wires formulated specifically for Arctic service. However, for selected applications, current commercially available weld consumables might produce improved properties by using welding techniques designed to provide more control over the resulting weld deposit microstructure.

This paper will identify some welding techniques that offer the potential to increase control over weld deposit bead size, bead placement and shape, with the objective of generating weld microstructures that result in improved fracture toughness as compared with more conventional welding techniques. In addition, the results of some early-stage work currently underway at EWI to evaluate some of these techniques will be presented.