Straight seam steel pipe induction ring installation

Straight seam steel tube high-frequency induction ring should be as close as possible to the position of the squeeze roller. The internal stress of the steel tube is small and evenly distributed, which can effectively prevent stress corrosion cracking, high dimensional accuracy, and easy on-site welding construction.

If the induction ring is far away from the squeeze roller, the effective heating time is longer, the heat affected zone is wider, and the strength of the weld is reduced. The edge of the welding seam does not reach the welding temperature, and the metal structure remains solid, forming unfused or not fully penetrated. When the input heat is too much, the edge of the heated weld exceeds the welding temperature, causing over-burning or droplets, causing the weld to form a melt hole.

The resistor is one or a group of special magnetic rods for welded tubes. The cross-sectional area of the resistor should not be less than 70% of the cross-sectional area of the inner diameter of the steel pipe. The proximity effect is generated, and the eddy current heat is concentrated near the edge of the weld seam of the tube blank, so that the edge of the tube blank is heated to the welding temperature.