IMPROVED PULSED GMAW TECHNIQUES FOR HANDHOLE PIPE WELDING

摘要

The invention relates to improved pulsed GMAW technique for hand hole pipe welding and in particular for hand-hole pipe to dish end cover butt welding in headers for boiler components where the conventional adopted process was by Gas Tungsten Arc Welding (GTAW) for root passes and shielded Metal Arc Welding (SMAW) for further passes. The improved process discloses root pass welding by using wave form controlled Gas Metal Arc Welding (GMAW) commonly referred as Surface Tension Transfer (STT) process followed by pulsed current GMAW (P-GMAW) process for filler passes by setting parameters and setting arrangement which has ensured higher productivity, minimized rejection rate as well as eliminating dependency over skilled welding personnel.