Influence of Electrode Rotation in Electroslag Remelting on the Anisotropy of Ingot Properties

Abstract

In the analysis of electroslag remelting, attention is focused here on how rotation of the consumable electrode affects the physicomechanical properties of the ingot (billet) produced. In electroslag remelting with rotation of the consumable electrode around its axis, an ascending heat flux is formed in the slag bath. That improves the hydrodynamic conditions in the mold in terms of heat utilization. With rotation of the consumable electrode, centrifugal forces act on the film of liquid metal formed at the end of the electrode, resulting in radial flow of the metal droplets. The droplets subsequently break away from the electrode perimeter. Thus, the droplets of electrode metal enter the metal bath closer to the mold wall. That ensures a more uniform temperature front in the bath. With decrease in the temperature gradient over the bath cross section, a flatter solidification front is obtained. Such electroslag remelting with rotation of the consumable electrode will affect the physicomechanical properties of the ingot (billet) produced. Remelting trials are conducted to establish the resulting influence on the metal properties. Data are presented for the experimental electroslag remelting of AISI420 streel electrodes in an A-550 system, using different methods. The experimental data show how rotation of the consumable electrode affects the remelting conditions, the solidification of the ingot, and its physicomechanical properties. Its influence on the ingot properties is of particular interest: data regarding the microhardness, density, and size of the dendritic cell in the experimental samples are analyzed. It is found that, in electroslag remelting with rotation of the consumable electrode, the microhardness is more uniform in the transverse direction. In addition, with rotation of the consumable electrode, the dendritic cell is smaller, and the ingot density is higher, than in the classical technology without electrode rotation.