Submerged arc welding spiral steel pipe uses continuous welding wire as the electrode and filler metal. During operation, the welding area is covered with a layer of granular flux. The large-diameter spiral tube arc burns under the flux layer, melting the end of the welding wire and part of the base metal. Under the action of arc heat to form a weld, the upper flux melts the slag and reacts metallurgically with the liquid metal. The molten slag floats on the surface of the metal molten pool. On the one hand, it can protect the weld metal, prevent air pollution, and produce physical and chemical reactions with the molten metal, improving the structure and performance of the weld metal. On the other hand, it can also make the weld metal Slowly cool down. Submerged arc welding can use a larger welding current, and its advantages are good weld quality and high welding speed. Therefore, it is particularly suitable for welding large-diameter spiral steel pipes. Most of them adopt automated welding, which has been widely used in the welding of carbon steel, low alloy structural steel, and stainless steel.
High-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 based on the way high-frequency current generates heat in the workpiece. When contacting high-frequency welding, high-frequency current is transmitted into the workpiece through mechanical contact with the workpiece. During induction high-frequency welding, the high-frequency current generates an induced current in the workpiece through the coupling effect of the induction coil outside the workpiece. High-frequency welding is a highly specialized welding method, and special equipment must be equipped according to the product. High productivity, welding speed can reach 30m/min. Using solid resistance heat as the energy source, the resistance heat generated by high-frequency current in the workpiece is used during welding to heat the surface of the welding area of the workpiece to melting or close to a plastic state, and then apply (or not apply) upsetting force to achieve the bonding of metals.
Post time: Feb-21-2024