Views: 0 Author: Site Editor Publish Time: 2021-05-24 Origin: Site
At the end of the pre-welded steel pipe
(1) before milling, weld the pilot arc plate
(2) to find a pilot arc plate with the same thickness as the base material. The distance between the roller and the cutter head should not be too narrow. Later, you will have to apply force laterally)
(3) Method of welding the pilot arc plate: first process the pilot arc plate into a single-sided groove. You can use band saw, sawing
(4) and then weld the pilot arc plate to the end of the steel pipe pre-welded into the steel plate (the front end cannot be pre-welded) and use the bow clip to use the copper backing plate or refractory bricks, ceramic gaskets, etc. Use the reinforcing plate to make the reserved bend first.
(5) Use carbon dioxide gas to protect the welding firmly. The welding pilot arc plate must be before the milling process.
(6) Start manual welding at the pipe end of the pre-welding machine, the shorter the better (should be kept within 2 cm, otherwise weld bead is prone to appear) to prevent the steel pipe from cracking : The long weld bead is not allowed, and the long weld should be close to the automatic weld.
(7) The pipe end can be welded more on the pilot arc plate to prevent the steel pipe from cracking. If the opening of the pilot arc plate is too large, special tools can be used to eliminate it before welding.
(8) After the steel pipe pre-welding is completed, use a cutting torch to cut the pipe end, and then weld the single-piece single groove arc pilot plate, and weld it firmly to prevent gouging during internal and external welding, and steel pipe cracking when manual welds are removed.
(9) Manual CO2 gas shielded welding wire should choose a thinner wire with a diameter of 0.8-1.2mm, not a 1.6mm diameter welding wire first. The quality of the welded pilot arc plate directly affects the quality of the weld at the end of the steel pipe.
(10) For thick-wall welding, the horizontal inclination angle of the trolley should be adjusted. For thick-wall welding, uphill or horizontal welding should be selected, and the welding wire should be tilted backward.
(11) For thin-wall welding, the horizontal inclination angle of the trolley should be down-slope welding. The welding wire should be tilted forward, but in the end it needs to look at the appearance and internal quality of the weld formation.
(12) The elongation of the welding wire is 6-8 degrees of the diameter for double-wire welding. , Single wire welding is 8-10 times the diameter.
The pilot arc plate plays a prominent role in the welding process of submerged arc welded steel pipes, and effectively guarantees the quality qualification rate of the submerged arc weld. Good starting work is an important process for successful submerged arc welding.