Method for welding red copper pipe fitting and bronze flange joint

The invention discloses a welding method for a red copper pipe fitting and a bronze flange joint, and belongs to the technical field of ocean engineering. The welding method for the red copper pipe fitting and the bronze flange joint comprises the following steps: forming a groove in the edge of a flange inner ring, and embedding the end part of the pipe fitting into the flange inner ring to form a fillet weld; performing positioned welding in the fillet weld by using alternating current TIG welding; under mixed protective gas of 30% of helium and 70% of argon, layered backing welding and cosmetic welding are conducted on the fillet weld in sequence through the alternating current TIG welding process, and the interlayer temperature range is controlled to be 100-120 DEG C; wherein a leftward welding method is adopted for backing welding, after electric arc ignition, stopping is conducted for 8-10 seconds at the ignition position, the center of the electric arc deviates to the flange side, a welding gun does no