SUBMERGED-ARC WELDS FOR OFFSHORE STRUCTURES: MEETING AN AS-WELDED COD REQUIREMENT

Crack opening displacement (COD) has gained considerable acceptance as a fracture toughness criterion for welds in highly-stressed parts of offshore production platforms, and two major oil companies operating in the North Sea require their fabricators to attain 0.25 mm COD at -10 degrees C for welds in the splash zone. Economic and other considerations have focused attention on achieving this degree of fracture toughness in the as-welded condition, but this has been a difficult problem. The Authors discuss the problem and describe in some detail an experimental investigation in which changes in welding consumables and procedures were introduced in the submerged-arc welding of 50-mm thick C-Mn plate until, finally, an as-welded COD toughness above the minimum specified was consistently obtained. The investigation, conducted on a series of eight panels, included fracture toughness and microstructural studies. The results of this successful investigation are discussed, and among the several conclusions drawn it is mentioned that the overall influence of procedural factors (e.g., back gouging, root position, and edge preparation) on the measured COD was found to be only marginal compared with changes in wire type, and that differences between the COD results and those of Charpy tests (carried out on six of the panels) emphasise the difficulties encountered when specifying welding-procedure qualificaton requirements. Order from BSRA as No. 49,550.

  • Corporate Authors:

    IPC Science and Technology Press Limited

    IPC House, 32 High Street
    Guildford, Surrey  England 
  • Authors:
    • Kamath, M S
    • Abson, D J
    • Garland, J G
  • Publication Date: 1978-7

Media Info

  • Features: References;
  • Pagination: p. 385
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00188800
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Mar 14 1979 12:00AM