Large diameter thick wall straight seam double submerged arc welding pipe welding technology invented back in 1940, a new welding method. It is the same place, and manual welding or the use of slag to protect it, but this is not a slag electrode coating. It is dedicated to melting out of the flux. The flux system consists of a funnel filled with flux through a pipeline to be welded to the front.
Generally biased towards sided submerged arc welding straight seam steel pipe weld requirements, straight seam double submerged arc welded steel tubes used for water, gas pipelines, construction, electrical engineering, mechanical, bridge beams, steel, basic piling and other facilities. In recent years a large steel structure with a large amount of straight seam steel pipes. Pipe material, pipe bending properties, especially in the last few years, the thickness of the steel pipe demanding requirements, resulting in a lot of works on the pipe thickness requirements and material requirements are very stringent. Spiral pipe in oil and gas pipelines are widely used in 70 to 80 years by the LSAW and ERW tubes serious challenge, since oil and gas pipeline in the world is no longer substantially spiral steel pipe, many large international oil companies and oil and gas pipeline companies have been allowed spiral submerged arc welded pipe pipe selection. This is because the development of the pipeline industry increasingly high reliability requirements, while spiral welded pipe manufacturing itself can not overcome because of its flaws, making it difficult to meet the objective requirements of the development.
The second difference is not used electrode using wire, because the wire can be continuously sent; electrode, we gotta burn a welding electrode head gave a throw, and the operation was stopped, and then for electrode welding. Production of large diameter thick wall straight seam welded steel pipe products technology is currently used in this package, this technology has greatly improved our productivity and weld quality. In this way, the first advantage is fully automated; second advantage, it is carried out under submerged arc welding, the heat exchange and so it is relatively strong protection performance, higher quality weld out; third advantage as submerged arc welding arc welding flux buried underneath, so it can use a large current, welding efficiency is relatively high, the recent progress of our country's natural gas pipeline project. After wire changed, with the delivery device and the wire coil wire, the wire is continuously sent, this welding process is continuous feeding of the wire and the solder to melt under the coverage of the particulate ignition of the arc, the welding wire, base material and flux melting and evaporation constitute part of a cavity, the cavity inside the arc is stable combustion, so call it submerged arc welding.
