TRANSVERSE MAGNETIC FIELD INPUT DEVICES FOR ARC WELDING AND SURFACING PROCESSES (Review)

摘要

Application of controlling longitudinal and transverse magnetic fields is promising in arc welding and surfacing, allowing improvement of efficiency of electrode wire melting, refining of the structure of weld metal (deposited bead) and reducing the depth of base metal penetration. In arc welding and surfacing the influence of transverse magnetic fields on geometrical dimensions of welds (beads) and electrode melting efficiency was mainly determined. These works either do not give the input device designs, or they are presented without discussion of the subject of optimality of the used designs, or dimensions of each element of these devices. The objective of this work was analysis of known designs of input devices to assess the effectiveness of their application in arc welding and surfacing. It is shown that the devices described in publications consist of an electric magnet with ∏-shaped ferrite core with an air gap and windings. In some works just the transverse component of magnetic field B_x was measured, and longitudinal component of induction B_z induced by the applied input device, was not measured. However, the shape and dimensions of the cross-section of welds and deposited beads in this case could be influenced not only by transverse B_x, but also by longitudinal component of magnetic field B_z. Design features, as well as distribution of induction components B_x, B_z generated by known circuits of devices for application of transverse magnetic fields in the zone of welding arc and pool, were analyzed, and their disadvantages were noted. Urgency of development of new circuits is shown, as well as rationality of optimization of structural dimensions of known circuits of the devices to improve the effectiveness of are welding and surfacing with application of transverse magnetic fields.