TWI Industrial Member Report Summary 233/1984
By N A Kennedy
Published literature concerning the use of narrow gap preparations in the submerged-arc welding of steels is reviewed. Mention is made of the process variations in current use and an outline is given of the equipment and consumable requirements associated with this technique. The effects of welding in a deep, narrow groove on the metallurgical structure and the mechanical properties of the weld metal and heat affected zone (HAZ) are examined. It is concluded that the technique offers potential advantages in the manufacture of heavy-section components by increasing joint completion rate but that selection of a suitable flux is vital for defect free welds. High standards of process control are essential during all aspects of the welding operation. The most widely suitable process variant involves the deposition of two weld heads per layer of metal.