High frequency welding machine welding method: induction welding and contact welding

The induction welding of the high-frequency welding machine is that a multi-turn or one-turn induction coil is wrapped outside the welded steel pipe. The effect of a single turn is not as good as that of multiple turns, but the multi-turn induction coil is not easy to make and install. It is recommended that you keep the gap between the induction coil and the surface of the steel pipe 5~8mm, because the distance between the steel pipe and the surface of the induction coil is small, the efficiency is high, and it is easy to cause discharge between the induction coil and the pipe.

But when induction heating equipment is used for induction welding, because the steel plate is not in contact with the induction coil, there is no wear phenomenon. Because the induced current is relatively stable, this is conducive to ensuring the stability of welding. The surface quality of the steel pipe during welding is relatively good, and the weld seam is flat. For example, when producing high-precision pipes (API), induction welding is basically used.

Contact welding is that a pair of copper electrodes are in contact with both sides of the welded steel pipe, the induction current has better penetration, and the two effects of high-frequency current are maximized because the steel plate and the copper electrodes are in direct contact, so induction heating equipment The welding efficiency of contact welding is relatively high, but the power consumption is relatively low, and it is widely used in the production of high-speed and low-precision pipes. However, some thicker steel pipes use contact welding.

However, there are two shortcomings in the contact welding of the high-frequency welding machine: one is due to the influence of the edge straightness and the flatness of the surface of the steel plate, but the current stability of the contact welding is not good, and the current stability of the contact welding is poor. It is recommended that you This method is not used for thin-walled tubes and their high precision welding.