Double-sided Submerged Arc Welding (LSAW - Longitudinal Submerged Arc Welded), a new kind of welding method, was invented in 1940. Compared with the manual welding, the same point is that LSAW is using slag protection technology, but the slag is not the coating of electrode. The welding flux is made of by the slag specially smelting. This system of welding flux composed of a funnel transfer to the front of the welding through a pipeline.
The second difference is that the electrode was not used while adopts the welding wire because welding wire can be provided continuously. After having burned a electrode, we must throw a welding head, and we have to stop the operation, moreover, the operation continues by changing electrode to weld once again.
The first advantage of using this method is that it is fully automated. The second advantage is that the heat transfer and protection performance are stronger and the welding quality is higher under the submerged arc welding. The third advantage is that it can be used in a large current, and the high welding is efficient, as a result of submerged arc automatic welding arc is buried under the fluxing agent because submerged arc automatic welding arc is buried under the fluxing agent.
Pipeline, a kind of high strength steel, pre-makes into a part inside in a factory, and then is brought to the site and weld outdoors. Welding technology of pipeline made in factory is using submerged arc welding. Submerged arc welding has now become the double wire submerged arc welding and many wire submerged arc welding. The latter further improves the efficiency.
