Search

Electrovortex flow of liquid metal in a vessel relates to melt stirring in electrometallurgical processes and aggregates, such as welding, electroslag remelting, electrical arc furnaces and others. Maximum values of electromagnetic force and flow velocity develop in the zone between or under the electrodes, where sophisticated 3D flows are formed. In the paper, examples of electrovortex flows near two fully submerged electrodes with bifilar DC supply are discussed. The measured electrical potential and 3D self-magnetic field compared with results of numerical calculation and with a quasi 2D model of EM fields are discussed. Numerically computed 3D electrovortex flow patterns are presented for two regimes, i.e. (i) laminar and (ii) turbulent obtained with the LES approach. There is good qualitative and quantitative agreement between experimental data, analytical and numerical computation results, as well as with some previously published results. [ABSTRACT FROM AUTHOR]

With the help of numerical and experimental methods it was shown that a stationary external magnetic field, which causes an azimuthal swirl of axisymmetric electric flow, leads to the generation of intensive hydrodynamic self-oscillating processes in a current- carrying liquid metal. Calculations are in good agreement with experimental data. [ABSTRACT FROM AUTHOR]

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]