Control of the Best Efficiency of High Frequency Welded Pipe Welding Process

60Hz power is converted to high frequency power for solid metal welding of 90% efficiency. In high frequency welding, the welding power is generally above 100kW, heating, impedance, and the power consumption of the roller is 4/5, so the key to reduce the power loss is to set the reasonable coil, the impedance and the reasonable configuration of the rolling mill. In most cases, by optimizing welding process, the power loss can be reduced by 50%, which can improve welding quality, reduce downtime and increase output.


The high frequency welding mechanism is: the voltage passes through the edge of the opening part of the pipeline, and is used to reach the accumulation point. When the current flows through the contact point, the metal is rapidly heated. The heat of the extruding roller is pressed through the melting of the metal and the impurity is extruded through the weld.


Technically speaking, impedance is the main consumption of low-frequency current through resistive elements. With the increase of frequency and the increase of magnetic field, induction resistance becomes the main factor of impedance and increases with the increase of frequency. In the welding process, as the induction coil of primary winding, the size should be reduced properly, and the power can be adjusted by electromagnetic coupling, and the magnetic loss caused by high frequency is related to the number of turns and current of the coil. The frequency of 60Hz requires hundreds of turns of coils and thousands of ampere currents; high-frequency welding is usually 7% coils and hundreds of ampere currents. In addition, high frequency welding can also be beneficial to skin effect and proximity effect.


High frequency welding is inefficient because the position and impedance of the induction coil are not very good. When the voltage is added to the edge of the billet, some current flows through the V - shaped area along the edge and heating the steel side; the other flows through the inner ring of the open tube, and the outer ring surface returns to produce power loss.