The professional technology of straight double submerged arc welded steel pipe (steel saw pipe) is as follows:
1. Dual submerged arc welding (DSAW) was invented in 1940. Residue protection was still used in the same place as manual welding, but it was not a dreg electrode coating. In the same place as manual welding, DSAW still uses residual protection, but this is not a slag electrode coating, especially a molten flux. The flux system consists of a funnel filled through a pipe and welded in front.


2. The second difference is the use of wires, because wires can be sent continuously; electrodes, we burn a welding electrode must have a head thrown it, and the operation has to stop, and then change the electrode welding.


In this way, the first advantage is full automation; the second advantage is that under SAW, its heat exchange and protection performance is relatively strong, and the welding quality is high; the third advantage is that because SAW is embedded in flux, it can use high current and high welding efficiency, which is the latest development of natural gas pipeline engineering in China.


4. Later, it was changed to wire. With the wire feeding device and wire axle continuously sent to the wire, the welding wire was continuously fed in, ignited, covered with fusible particle flux in the arc, the welding wire, partially melted and evaporated base metal and solder formed a cavity, and the arc stabilized combustion chamber in the interior, so it was called submerged arc welding. The arc is buried inside the cavity.


5. Pipeline is a high-strength steel pipe. This kind of pipe is the first pre-formed part in the factory, and then goes to the spot. In the field of welding, submerged arc welding is used in the production of pipeline such as welding technology. Now, the submerged arc welding has developed into a double-wire submerged arc welding and multi-wire submerged arc welding to further improve efficiency.