High-frequency straight seam welded steel pipes can be divided into straight seam high-frequency resistance welded steel pipes and straight seam high-frequency induction welded steel pipes according to different high-frequency welding processes. The forming process generally adopts roll bending cold forming.
High-frequency straight seam welded steel pipes are generally produced in smaller diameters, generally with an outer diameter of 660mm or less than 26 inches. Its characteristics are: fast welding speed. For example, for steel pipes with an outer diameter of less than 1 inch, the welding speed can reach up to 200 meters/minute. For steel pipes with an outer diameter of 25 inches, the welding speed can also reach more than 20 meters/minute. The welding method is crimping instead of fusion welding. Compared with fusion welding, the welding heat-affected zone is relatively small and has little impact on the structure of the base metal. The strength and toughness of the weld after welding are different from those of the parent material. According to the use requirements, the internal and external welding burrs can be cleaned or not cleaned. The workpiece does not need to be cleaned during welding, and thin-walled pipes and metal pipes can be welded.
High-frequency straight seam welded steel pipe process: slitting - uncoiling - strip leveling - head and tail shearing - strip butt welding - loop storage - forming - welding - burr removal - sizing - flaw detection - flying cutting - initial inspection ―Steel pipe straightening―Pipe section processing―Hydraulic testing―Flaw detection and testing―Printing and coating―Finished products. High-frequency straight seam welded steel pipes are mainly used in water supply projects, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, and urban construction.
For liquid transportation: water supply and drainage. For gas transportation: coal gas, steam, liquefied petroleum gas. For structural purposes: piling pipes, bridges; pipes for docks, roads, building structures, etc.
