LSAW-Longitudinal Submerged Arc Welded is a new welding method invented in 1940. It is the same as the previous manual welding. It is still protected by slag, but this slag is not the coating of the electrode. The double-sided LSAW steel pipe and the manual welding are the same in that it is still protected by slag, but this slag is not the coating of the welding rod, and is a specially smelted flux. This soldering system is transported by a funnel-loaded flux through a pipe to the front to be welded.
The second difference is that the welding wire is not used, because the welding wire can be continuously fed; the welding rod, we burned a welding rod and always have a welding rod head to throw it, and the operation has to stop, change the welding rod and then re-weld.
The first advantage of this method is that it is fully automated; the second advantage is that it is welded under the submerged arc, so its heat exchange and protection performance is relatively strong, the quality of the welding is relatively high; the third advantage Because the arc is buried under the flux under the automatic welding of the submerged arc, it can use large current and the welding efficiency is relatively high. Recently, the West-East Gas Pipeline Project is underway in our country.
After being changed into a welding wire, the wire is continuously fed to the welding wire by means of a wire feeding device and a wire reel. This welding method is a continuous feeding wire which is ignited by a meltable granular flux to ignite the arc and the base metal. A part of the flux melts and evaporates to form a cavity, and the arc is stably burned in the cavity, so it is called submerged arc automatic welding. The arc is buried in the cavity.
The pipe is a kind of high-strength steel. The pipe is pre-formed in the factory and then taken to the construction site for welding in the field. The welding process of the pipe is made by submerged arc welding. Now submerged arc welding . It has been developed to have double wire submerged arc welding and multi-wire submerged arc welding, and the efficiency is further improved.