High frequency welding methods

High-frequency welding with two ways: contact welding and induction welding.

Resistance welding electrodes is a pair of copper on both sides of the steel pipe welded portion in contact with the induced current penetration is good, due to the two high-frequency current effects copper electrode in direct contact with the steel plate to obtain maximum utilization, the contact welding welding efficiency higher and lower power consumption, has been widely used in high-speed low precision pipe production, especially in the production of thick steel pipe generally requires the use of contact welding. But there are two drawbacks to contact welding: First contact with the copper electrode plates, wear out quickly; the second is due to the influence of the edge of the plate surface flatness and straightness, and poor contact welding current stability, and high internal and external weld burr when welding precision and thin-walled tube is generally not used.

Induction welding is one or more turns of the induction trap outside the welded steel pipe, multi-turn better than a single turn, but much more difficult to turn induction coil fabrication and installation. Induction coil and steel surface high pitch hour efficiency, but is likely to cause the discharge pipe between the induction coil and generally to keep away from the pipe surface induction loop has 5 ~ 8 mm gap is appropriate. When using induction welding, due to the induction coil is not in contact with the plate, so there is no wear and tear, which induced current is more stable, to ensure the stability of the welding, good surface quality when welding steel pipe, weld formation, such as in the production of high API When precision tubes, basically in the form of induction welding.