The welding method of high-frequency stainless steel welded pipe is roughly divided into two methods, namely: contact welding and induction welding. What are the special features of the two different welding methods?

1. Contact welding

Contact welding is a pair of copper electrodes that are in contact with both sides of the welded steel pipe. The induced current has good penetrability. The two effects of high-frequency current are greatly used because the copper electrode directly contacts the steel plate. With high efficiency and low power consumption, it is widely used in the production of high-speed low-precision pipes, and contact welding is generally required when producing particularly thick stainless steel high-frequency welded pipes.

But there are two disadvantages of stainless steel contact welding:

1. Due to the influence of the surface flatness of the stainless steel plate and the straightness of the edge, the current stability of contact welding is poor, and the internal and external burrs of the weld are high. Generally, contact welding is not used when welding high-precision and thin-walled tubes.

2. The copper electrode is in contact with the steel plate and wears out quickly;

2. Induction welding

Induction welding is a one-turn or multi-turn induction ring wrapped around the welded steel pipe. The effect of multi-turn is better than single-turn, but the production and installation of multi-turn induction ring is more difficult. When the distance between the induction ring and the surface of the steel pipe is small, the efficiency is high, but it is easy to cause discharge between the induction ring and the pipe. It is generally appropriate to maintain a gap of 5 ~ 8 mm from the surface of the steel pipe. When induction welding is used, since the induction ring does not contact the steel plate, there is no abrasion, and the induction current is relatively stable, which ensures the stability during welding. The surface quality of the steel pipe during welding is good, and the weld seam is smooth. For precision tubes, induction welding is basically used.