China Spiral Steel Pipe will strip into welded pipe unit, the multichannel roll rolling, strip steel rolled up gradually, there is an open space form of round billet, adjust the quantity of the squeezing roller, make the weld gap control in 1 ~ 3 mm, and make joint flush on both ends.
1. If the gap is too large, the adjacent effect will be reduced, and the eddy current heat is not enough.
2. If the clearance is too small, the proximity effect will increase, and the welding heat will be too large, resulting in the weld loss. Or the weld is extruded, rolled and formed deep pit, affecting the weld surface quality.
When the two edges of the tube are heated to the welding temperature, the common metal grains penetrate and crystallize, forming a solid weld at the end of the extrusion roll. If the extrusion pressure of spiral steel tube is too small, the number of common crystals will be small, and the strength of the weld metal will decrease, which will cause cracking after stress. If the extrusion pressure is too high, the molten metal will be extruded, which not only reduces the weld strength, but also produces a large number of internal and external burrs, and even defects such as welding seams. As Spiral Steel Pipe Supplier,we keep trying.