The
electric resistance welded pipe (
ERW steel pipe) is a method in which a weld is combined and pressure is applied through an electrode, and the electric current is welded by the electric resistance generated by the contact surface of the joint and the adjacent region. When high-frequency currents pass through metal conductors, two strange effects occur: skin effect and proximity effect, high-frequency welding is to use these two effects to weld the steel pipe, these two effects are the basis for achieving high-frequency welding of metal. High-frequency welding uses the skin effect to concentrate the energy of the high-frequency current on the surface of the workpiece; the proximity effect is used to control the position and range of the high-frequency current flow path. The speed of the current is very fast, it can heat, melt and join the adjacent steel plate edges in a short time.
Geometric seamlessness is to remove the internal and external burrs of the ERW steel pipe. Due to the continuous improvement and improvement of the structure and cutter of the inner burr removal system, the removal of the inner burr of the large and medium diameter steel pipe has been well treated. The inner burr can be controlled at about -0.2mm to about 0.5mm.
Physical seamlessness means that there is a difference between the metallographic structure inside the weld and the base metal, which leads to a decrease in the mechanical properties of the weld zone, and measures need to be taken to make it uniform and uniform.
