High frequency welded steel pipe and submerged arc welded straight seam steel pipe

　　1. Straight seam steel pipe high-frequency welding process: according to the way high-frequency current generates heat in the workpiece can be divided into contact high-frequency welding and induction high-frequency welding. When in contact with high frequency welding, high frequency current is transmitted to the workpiece through mechanical contact with the workpiece. In the induction of high-frequency welding, the high-frequency current generates an induced current in the workpiece through the coupling action of the external induction coil of the workpiece. High-frequency welding is a specialized welding method that requires special equipment according to the product. High productivity and welding speed of 30m/min. That is to say, the weld is parallel to the surface of the steel pipe and will not be higher or lower than the surface of the steel pipe.

　　2. Straight seam pipe submerged arc welding process: Submerged arc welded steel pipe is also a welding method using arc as a heat source. In submerged arc welding, the arc is burned under the cover of a layer of granular meltable flux, and the arc light is not exposed. Submerged arc welding is named after this. The metal electrode used was a bare wire that was fed without interruption. Because submerged arc welding has a large penetration depth, high productivity, and high degree of mechanical operation, it is suitable for welding long welds of medium and heavy plate structures. It is widely used in the manufacturing sectors of shipbuilding, boilers and pressure vessels, bridges, overweight machinery, nuclear power plant structures, marine structures, weapons, etc. It is one of the most commonly used welding methods in the production of welded steel pipes.