A PROCESS OF NARROW GAP SUBMERGED ARC WELDING WITH COLD WIRE ADDITION AND AN APPARATUS FOR THE SAME

摘要

A process of narrow gap submerged arc welding with cold-wire addition comprises the steps of preparation of near parallel-sided edges for welding; ensuring that the included angle for the joint is in the range of 2-4° and width of the joint at the root is in the range of 18~25 mm; feeding one additional wire with special narrow gap nozzle and interfacing the additional wire-feeder with the existing wire feeder for controlling the wire feed rate, characterized in that the process enables savings of upto 70% in weld metal requirement and in that the excess energy available in the arc cavity melts the cold wire and eliminates heavy penetration, unfavourable micro-structure formation, high shrinkage and distortion of the main plate.