Introduction of High Frequency Straight Seam Welded Pipe

The high-frequency welding process is based on the principle of electromagnetic induction, as well as the skin effect of the AC charge in the conductor, the eddy heat flow effect, and the proximity effect. The edge steel of the weld is heated until it is heated to a molten state, and then Using the roller extrusion process, the butt weld can achieve intergranular bonding, so that the purpose of weld welding can be achieved. High-frequency welding is a kind of induction welding, and we can also call it pressure-based welding. High-frequency welding does not require filler materials for the weld seam, and there is no welding spatter during welding. The area affected by welding heat during the welding process is narrow, the shape after welding is very beautiful, and the mechanical properties of the welding are very good. Due to these advantages of high-frequency welding, high-frequency welded pipes are widely used in the production of steel pipes.

The high-frequency welding of steel pipes uses the skin effect and proximity effect of alternating current. After the steel is rolled and formed, a circular tube blank with a broken section is formed. One or a group of resistors are rotated near the center of the induction coil in the tube blank, and an electromagnetic induction loop is formed between the resistor and the opening of the tube blank. Under the effect of skin effect and proximity effect, the edge of the opening of the tube blank produces a strong and concentrated heat effect, which makes the edge of the weld seam rapidly heated to the temperature required for welding. After being squeezed by the pressure roller, the metal in the molten state realizes intergranular bonding, and forms a firm butt weld after cooling.