The difference between submerged arc welded spiral steel pipe and straight seam high frequency welded steel pipe

The difference between submerged arc welded spiral steel pipe and straight seam high frequency welded steel pipe

Submerged arc welding spiral steel pipe uses continuous welding wire as the electrode and filler metal. When working, the welding area is covered with a layer of granular flux. The large-diameter spiral pipe arc burns under the flux layer to melt the end of the welding wire and the local base material. Under the action of arc heat, the upper part of the flux melts the slag and metallurgically reacts with the liquid metal. The slag floats on the surface of the molten metal pool. On the one hand, it can protect the weld metal, prevent air pollution, and produce physical and chemical reactions with the molten metal to improve the strength and performance of the weld metal; on the other hand, it can also make the weld metal Cool down slowly. Submerged arc welding can use a larger welding current, and the advantages are good weld quality and high welding speed. Therefore, it is particularly suitable for welding large-diameter spiral steel pipes. And most of them use automatic welding, which has been widely used for welding carbon steel, low-alloy structural steel, and stainless steel.

High-frequency welding Co-frequency welding is a solid-phase resistance welding method. High-frequency welding can be divided into contact high-frequency welding and induction high-frequency welding according to the way that high-frequency current generates heat in the workpiece. When contacting high-frequency welding, high-frequency current flows into the workpiece through mechanical contact with the workpiece. During induction high-frequency welding, the high-frequency current generates induced current in the workpiece through the coupling action of the external induction coil of the workpiece. High-frequency welding is a highly specialized welding method, which must be equipped with special equipment according to the product. The productivity is high, and the welding speed can reach 30m/min. With solid resistance heat as the energy source, the resistance heat generated by the high-frequency current in the workpiece is used to heat the surface of the workpiece welding zone to a molten or nearly plastic state, and then the upsetting force is applied (or not) to achieve the metal bonding.