Method of welding of elements for the power industry, particulary of sealed wall panels of power boilers using MIG/MAG and laser welding

摘要

The subject of the invention is a method of welding of elements (4, 5) for the power industry, particularly of sealed wall panels of power boilers and steam generators. The method according to the invention consists in joining tubes (5)that form sealed walls with flat bars (4) by means of a high power fibre laser (3), wherein welding is realised as a double sided plain butt welding with no bevelling of the faces being joined, at a speed of more than 1 m/min, while the laser beam is either irradiated into a molten pool, such pool being formed in the process of MAG welding with noble gas shielding, or the laser beam is trailing after the pool up to 10 mm behind it, with the MAG process electric arc positioned at an angle 6 of 40-80° in the XZ plane and at an angle of 6 of 40-80° in the YZ plane, where the weld is remelted with the laser beam positioned at an angle of incidence ± of 1-5° in the XZ plane and at an angle Y of 1-5° in the YZ plane. In another embodiment of the invention filler wire is fed into the focal point of the laser beam and/or into the molten pool, and the process is realised in the manner described above.