In fact, the mechanism of resistance welding is very simple, mainly refers to the voltage passing through the edge of the opening portion of the tube blank, and the current is brought to the meeting point by induction. The metal is heated rapidly as current flows through the junction. The pressure of the squeezing roller is used to cause the metal to be heated and melted to achieve hot extrusion bonding.
At the same time, some of the impurities contained in it are also extruded from the weld. It should be noted that the placement of the resistor is important during the processing of the welded pipe. If you focus too much on the meeting point, you can get higher efficiency, but it is easy to damage. It is common to place the impeder in the tube so that it has a gap from the inner surface of the tube that is equivalent to the wall thickness of the tube.
In other cases, the small unit's resistor is mounted on the lower bottom of the Wuxi welded pipe. In this case, not only is the welding efficiency low, but it is also easily towed away when the pipe moves. Normally, the magnetic properties of the resistor should extend from the center of the induction coil to the point of compression. The minimum resistor length is the diameter of the squeeze roller plus the length of the induction coil.
In addition, in order to ensure the welding quality of the welded pipe, in the resistance welding, it is necessary to properly design the induction coil. It is generally safer to use a low voltage, high current device in solid state welding. This is because the power consumption of the working coil is the square of the current value, so even if the coil resistance is extremely small, more power is still consumed. It is recommended that the induction coil be usually fabricated by soldering an oxygen-free copper plate to a cooling tube.
In addition to these factors, the welding frequency should also be controlled during the welding of the welded pipe. Normally, high frequencies are suitable for the production of small diameter tubes, while low frequencies are suitable for the production of large diameter tubes. The best way is to make the welding frequency adjustable. High-frequency welding has been widely used in the production of Wuxi welded pipes, improving the efficiency of the welding process, not only reducing costs, but also improving product quality and output.
For more about resistance welding, visit:https://www.hu-steel.com/product90_985.html
For more information, visit: https://www.hu-steel.com