Manufacturing control of high frequency welding pipe

Sources: this site    Click:    Date: 2017-7-31 20:49:59

1.Pipe gap control
Adjust the extrusion volume of the squeeze roller, so thatboth ends of the weld to keep flush, opening angle of 7 degrees below the weldgap control in 1-3 mm. Weld control is too large, there may be poor welding,welds are not fused or cracked, weld control is too small, due to heat is toolarge, likely to cause weld burns, melting metal splash, tumor is too large,affecting welding quality The (Metal spatter reasons: squeeze the melting tubeedge, the weld inside the steam pressure is greater than the surface pressure)

2. High-frequency induction coil position control
The position of the induction coil should be on the samecenter line as the steel pipe, and the distance between the front end of theinduction ring and the center line of the pressing roller should be as close aspossible to the steel pipe,will reduce the strength of the weld. The couplingof the induction coil is as thin as possible. When the lap is used, the widthof the induction ring should be equal to the diameter of the pipe. The choiceof single or double lap has a great influence on high frequency oscillationfrequency and output efficiency.

3. Position control of the resistor (also known as magneticbar)
The resistor is a group or a dedicated magnetic bar whosecross-sectional area accounts for 70% of the cross-section of the pipe. Itsrole is to strengthen the electromagnetic induction, concentrated weld edge ofthe eddy current heat. Sometimes the outside of the weld plus some magneticrod, but also play a supporting role. The temperature of the magnetic bar has agreat influence on the permeability, and the higher the temperature, the lowerthe permeability. The magnetic bar should be placed in the V-zone heatingsection, the front position in the center of the squeeze roller, the magneticpole position and permeability directly affect the welding efficiency and weldquality.

4. Output heat control
High-frequency power input to the steel pipe weld part of theheat is called the input heat, the input heat is insufficient, the welding speed is too fast, the edge of the pipe body can not reachthe welding temperature, the formation of non-welded or not penetrated cracksbut the input heat is too large , The welding speed is too slow, prone toover-burning, so that the breakdown of the weld, resulting in metal splash, theformation of pores. By adjusting the high-frequency voltage or welding speedmethod to control the size of the input heat, so that the weld of the steelpipe does not appear without penetration and no welding phenomenon, to meet thewelding quality requirements.

In short, the production process of high-frequency welded pipe is a special process, each link is more important, theimplementation of strict control, the quality of welding and energy efficiencywill have a significant role.