Development of electroslag remelting technology for obtaining multilayer billets

Abstract

The paper analyzes the methods of external influence on the electroslag remelting process in order to obtain multilayer ingots. The method of electroslag remelting with rotation of the consumable electrode is proposed, which leads to the appearance of centrifugal force that affects the heat pattern in the metal bath by changing the place of delivery of electrode metal droplets and form the crystallization front, providing greater crystalline homogeneity in the axial direction. Application of the electrode rotation technology allows to obtain multilayer ingots with a minimum transition zone between layers of different chemical composition. For realization of this method it is necessary to give the electrode unidirectional or reversible rotation around its axis or the axis of the bath at asymmetric location of the electrode. The rotation speed of the electrode depends on its diameter. For electrodes with a diameter of 40–250 mm it is 30–90 rpm. Rotation of the consumable electrode has a complex positive effect on remelting performance: it increases productivity without increasing the suitable power for the slag bath; it increases refining capacity; it changes the place of electrode metal delivery into the metal bath and forms the crystallization front, providing greater crystalline homogeneity in the axial direction. Application of the technology of rotation of the consumable electrode makes it possible to introduce chemical composition-correcting additives into the liquid metal bath from the ingot surface by applying a coating consisting of filler material and water-based non-stick paint to the remelting electrode.