Welding method of spiral steel pipe

Welding method of spiral steel pipe Spiral pipe is a spiral seam welded pipe made of strip steel coil as raw material, extruded at regular temperature, and welded by automatic double-wire double-sided submerged arc welding process. The welding method of submerged arc automatic welding is the same as manual welding in that it still uses slag protection, but this slag is not the coating of the electrode, but the welding flux specially smelted. The characteristic of the welding method of the spiral pipe is: use an extrusion device to first squeeze the inner surface of the steel plates on both sides of the unwelded weld to eliminate uneven protrusions and ensure that the inner sides of the steel plates on both sides of the unwelded weld are clean and smooth , and then welded. At the same time, the extrusion device is also used as a positioning device for the welding head, that is, the welding head and the extrusion device are tightly fixed together, and when the extrusion device moves along the unwelded weld, it is ensured that the welding head is also accurately along the The unwelded seam moves to ensure that the welding head is always in the middle of the seam. In this way, it can ensure that the quality of the welds produced by the automatic welding of the production line is stable and excellent, and there is basically no need for manual repairs. This method of welding spiral pipes, first, realizes automation; second, it is welded under submerged arc, so its heat exchange and protection performance is relatively strong, and the quality of welding is relatively high; third This advantage is due to the fact that the arc is buried under the flux in submerged arc automatic welding. The difference of submerged arc automatic welding is: submerged arc automatic welding does not use welding rods, but welding wires, because the welding wires can be fed continuously; welding rods, we have to throw away a welding rod head after burning a welding rod, and the operation must be stopped. Change the welding rod and weld again. After changing to welding wire, the welding wire feeding device and the welding wire reel will continuously feed the welding wire. This welding method is to continuously feed the welding wire and burn the arc under the cover of the meltable granular flux to make the welding wire and base metal Part of the melting and evaporation of the flux forms a cavity, and the arc burns stably in the cavity, so it is called submerged arc automatic welding. Post time: Mar-29-2023