WELDING METHOD OF ELECTRIC WELDED PIPE

摘要

PURPOSE:To decrease the flow of reactive current by applying a DC magnetic field to a part of a composite pipe where high or middle-frequency currents are supplied thereby saturating magnetically the composite pipe member of this part. CONSTITUTION:A high or middle frequency induction coil 5 is used as a heater for materials 1 to be welded and further a DC magnetization coil 9 as a magnetically saturating device for a core material 8 is disposed on the outside of the materials 1. The composite pipe member near the position enclosed by the coil 5 is saturated magnetically by a DC magnetization coil 9, by which the current reactive for welding in the material 8 is considerably decreased and the electric effective power for welding is considerably increased.