High Frequency Steel Pipe Manufacturing Control

Weld control is too large, it may appear poor welding, weld cracking produce incomplete fusion or weld control is too small, due to the excessive heat, weld is likely to cause burning, molten metal splash, build-up is too large, affecting the quality of welding. (Splatter reasons: melt extrusion tube side, the internal pressure is greater than the surface of the weld steam pressure) induction coil placement should be in the same center line pipe, extruded from the end from the induction loop roller centerline. Under the premise of not burning squeeze rollers, depending on pipe size as close, too far away when the heat affected zone width, make the weld strength. Coupled induction coil more tightly as possible, the selection of a single circle, should be equal to the width of the induction coil pipe diameter. Optional lap or two laps great impact on high frequency oscillation frequency and output efficiency. Impedance is a group or a special magnet whose cross-sectional area of 70% attributable to the inner diameter of the steel pipe section. Its role is to strengthen the electromagnetic induction, eddy currents concentrate the heat weld edges. Sometimes add some magnets outside the weld, can also play a supporting role. Magnet permeability on temperature is large, the lower the temperature the higher the permeability. Magnet should be placed in the heating section V-zone, squeezing front roll center position, the position of the magnet and the magnetic permeability of welded directly affect the efficiency and weld quality. High-frequency power input to the heat pipe weld area called the input of heat, lack of heat input welding speed is too fast, can not reach the edge of the pipe welding temperature, the formation of incomplete fusion or penetration of the crack but excessive heat input When welding speed is too slow, too prone to burning, so that the weld breakdown, causing metal splash, the formation of pores. By adjusting the speed of the high-frequency voltage or welding method, the size of the control input of heat, the steel pipe weld neither appear nor appear incomplete penetration welding wear phenomenon, reaching the welding quality requirements. First, the role of guide roller to control the direction of the weld to ensure a straight seam welded pipe into the squeeze roller is not reversed, the second is to ease the tube extension and rebound edge seam determine the size of the opening angle. Adjustment steel pipe joints could easily lead to bad twist or take welding, pipe wavy edges and other defects.