Spiral steel pipe submerged arc welding process instructions

Submerged arc automatic welding is a new welding method invented in 1940. The same thing as the previous manual welding is that it still uses slag protection, but this slag is not the coating of the welding rod, but a specially smelted flux. This flux system consists of a funnel that carries the flux through a pipe to the front of the welding site. The second difference is that welding rods are not used, but welding wires are used, because the welding wires can be fed continuously to the welding rods. After we burn a welding rod, we have to throw away one of the welding rod heads, and the operation has to stop, change the welding rod, and then weld again. After changing to welding wire, use the welding wire feeding device and the welding wire spool to continuously feed the welding wire. This welding method is that the continuously fed welding wire ignites the arc under the cover of the meltable granular flux so that the welding wire and mother wire Part of the material and flux melts and evaporates to form a cavity. The arc burns stably in the cavity, so it is called submerged arc automatic welding. The arc is buried inside the cavity.

The first advantage of this method is that it is fully automated; the second advantage is that it is welded under submerged arc, so its heat exchange and protection performance is relatively strong, and the quality of the welded product is relatively high; the third advantage is that it is welded under submerged arc. Because the arc is buried under the welding flux in automatic submerged arc welding, it can use large currents and has relatively high welding efficiency. Recently, our country is undertaking the West-East Gas Pipeline Project. The pipeline is a kind of high-strength steel. This kind of pipeline A section is pre-made in the factory, and then taken to the construction site and welded in the field. The welding process of this kind of pipe in the factory is submerged arc welding. Now submerged arc welding has developed into double-wire submerged arc welding. , and multi-wire submerged arc welding, which further improves efficiency.