The main reason for demagnetization of spiral welded pipes - enhancing welding quality

During the production process of spiral welded steel pipes, especially during the welding process, the use of direct current welding results in the generation of a strong magnetic field at the welding head and welding wire due to the high current. This magnetic field causes the magnetic moments of the steel pipe body to align with the direction of the external magnetic field. After welding is completed, the magnetic field gradually decreases until it disappears. However, due to hysteresis, a certain magnetic flux density, commonly referred to as residual magnetism, remains on the pipe body. The presence of residual magnetism adversely affects subsequent welding operations, such as by influencing the stability of the welding arc, thereby reducing welding quality. Therefore, demagnetization treatment can eliminate or weaken residual magnetism, enhancing welding quality.