Manufacturing process of high-frequency straight seam steel pipe
The high-frequency straight seam steel pipe 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. The steel at the edge of the weld is locally heated to the molten state, and the butt weld is realized by the extrusion of the roller. Inter-crystalline bonding, so as to achieve the purpose of welding seams. High frequency welding is an induction welding (or pressure contact welding). It does not require welding filler, no welding spatter, narrow welding heat affected zone, beautiful welding molding, good welding machinery and other advantages, so it is affected by the production of steel pipes. Wide application. The high-frequency welding of steel pipes uses the skin effect and the proximity effect of alternating current. After the steel is rolled and formed, a round tube blank with a broken cross-section is formed. In the tube blank, one or a group of impedance are rotated around the center of the induction coil. (Magnetic rod), the resistor and the tube blank open teeth forming an electromagnetic induction loop, under the skin effect and the proximity effect, the edge of the tube blank open teeth generates a strong and concentrated thermal effect, so that the edge of the weld is quickly heated to the welding After the required temperature is pressed by the pressure roller, the molten metal achieves inter-granular bonding, and after cooling, forms a strong butt weld.