High frequency welded pipe

High frequency welded pipe

High-frequency welded pipe is also called high-frequency resistance straight seam welded pipe. Using the skin effect and proximity effect of alternating current, the hot-rolled coil is rolled to form a circular tube blank with a broken section, which is close to the induction coil in the tube blank. Rotate one or a group of resistors near the center, and the resistor and the opening of the tube blank form an electromagnetic induction loop. Under the action of the skin effect and the proximity effect, the edge of the tube blank opening produces a strong and concentrated thermal effect, which makes the edge of the weld bead. After being rapidly heated to the temperature required for welding and extruded by the pressure roller, the metal in the molten state realizes intergranular bonding, and after cooling, a firm butt weld is formed.

The high-frequency welded steel pipe is different from the ordinary welded pipe welding process. The welding seam is formed by melting the base material of the steel strip body, and the mechanical strength is better than that of the ordinary welded pipe. The appearance is smooth, the precision is high, and the cost is low. The welding methods of high frequency welded steel pipes and submerged arc welded pipes are significantly different. Since the welding is completed instantaneously at high speed, it is much more difficult to ensure the welding quality than submerged arc welding.