Welding Frequency Influences the Quality of Welded Steel Pipe

In general, the influence on welded steel pipe quality because of high welding frequency is as follow.

Steel weld gap control
When the welded steel pipe is in the process of welding, please ensure the opening angle of the weld flush is in 7degree or smaller, and the gap is between 1-3 mm. Otherwise, the welding of the steel pipe may be poor, such as the weld crack produced on the surface of the welded steel pipe is incompletely fusion. On the contrary, if the weld control is too small, there are also severe problems caused by excessive heating, for example, weld burning, molten metal splash, and in turn influence the quality of welded steel pipe. Why the molten metal splashes is because the pressure of the internal is greater than the pressure on the weld surface when the melt is out of the pipe side.

Regulation of high-frequency induction loop position
Usually, the induction coil loop should be placed in the same center line pipe. When the loop is distant from the squeeze, the squeeze rollers will not burn. Whether it will burn or not depends on the size between the induction loop and the welded structural steel pipe. If the size is too big, and then the induction loop is too far away from the welded steel pipe, the strength of welding will decrease. The tighter the coupled induction coil, the better the welding strength. In addition, the diameter of a single circle must be equal to the width of the induction coil pipe. The oscillation frequency and output efficiency can be affected by optional lap or two laps.

Magnet position control
The magnet, which is also called impedance, is one of the most important parts of the cross-sectional area of the welded steel pipe. It can be used to strengthen the electromagnetic induction, and concentrate the heat weld edges. If the temperature is lower, then the permeability of the magnet will be higher. Besides, where to place the magnet may have an great influence on the efficiency and quality of the carbon steel pipe welding, so it is better to place the magnet in the heating section V-zone, which is front of the roll center.