Efficiency of gas shielding in welding joints with deep and narrow gaps

摘要

Investigations into the efficiency of gas shielding in welding were greatly intensified after the publication of Montevski~1 . At that time, there were two directions in the development of torches for welding joints with deep and narrow gaps. In the first case, the nozzles of the torches were positioned above the surface of the edges and the shielding jet, flowing into the gap, ensuring efficient shielding at a depth of the order of 0.8-0.9D (D is the diameter of the outlet orifice in the cross, section of the nozzle). In the second case, the nozzles of the torches were inserted into the gap and efficient gas shielding was provided only in the immediate vicinity of the weld pool.This created difficulties in service, shortened the service life and impaired reliability~(2,3).