METHODS OF GENERATION OF EXTERNAL MAGNETIC FIELDS FOR CONTROL OF ELECTROSLAG WELDING PROCESS.

Efficiency of application of electromagnetic actions for control of joint formation during electroslag welding is determined in many respects by application of external magnetic fields to welding zone and structural peculiarities of corresponding devices. The aim of present work lied in analysis of methods for generation of external magnetic fields during electroslag welding of butt joints and evaluation of their effect on weld pool melt. The main methods of generation of longitudinal and transverse magnetic fields in a welding gap are considered, and principal schemes of corresponding electromagnetic devices are given. It is shown that direction and intensity of electromagnetic force effecting the weld pool melt is determined first of all by spatial orientation of the external magnetic field in relation to object being welded, value of field magnetic induction and its frequency characteristics. Rationality of application of that or another scheme of application of magnetic field in the gap depends on welded joint parameters, and it should be considered separately for each individual case. Appropriateness of application of magnetic fields providing constant (cyclic) rearrangement of hydrodynamic structure of flows in the weld pool or creating melt vibration was indicated. In this case, usage of pulsed magnetic fields generated by discharges of capacitor batteries to electromagnet coil is perspective. Relevance of development of new schemes and devices for generation of magnetic fields and their power sources is shown. [ABSTRACT FROM AUTHOR]