High-frequency welding process: Straight seam steel pipe is a steel pipe made by rolling a long strip of a certain specification into a round pipe through a high-frequency welding unit and welding the straight seam. The shape of the steel pipe can be round, square, or irregular, depending on the sizing and rolling after welding. The main materials of welded steel pipes are low carbon steel and low alloy steel or other steel with σs≤300N/mm2 and σs≤500N/mm2.
The production process of high-frequency welding of straight seam steel pipes is as follows: High-frequency welding is based on the principle of electromagnetic induction and the skin effect, proximity effect, and eddy current thermal effect of AC charges in the conductor so that the steel at the edge of the weld is locally heated to a molten state. The extrusion of the roller enables the butt weld to achieve intergranular bonding, to achieve the purpose of weld seam welding. High-frequency welding is a kind of induction welding (or pressure contact welding). It does not need weld filler, no welding spatter, narrow welding heat-affected zone, a beautiful welding shape, and good welding mechanical properties. Therefore, it is favored in the production of steel pipes. Wide range of applications. The high-frequency welding of steel pipes uses the skin effect and proximity effect of alternating current. After the steel (strip steel) is rolled and formed, a circular tube blank with a broken section is formed, which rotates a circle near the center of the induction coil in the tube blank. Or a group of resistors (magnetic rods), 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, making the edge of the weld seam Rapidly heated to the temperature required for welding and squeezed by the pressure roller, the metal in the molten state realizes intergranular bonding, and forms a firm butt weld after cooling.
Post time: May-09-2023