ВЛИЯНИЕ ВРАЩЕНИЯ РАСХОДУЕМОГО ЭЛЕКТРОДА ПРИ ЭЛЕКТРОШЛАКОВОМ ПЕРЕПЛАВЕ НА АНИЗОТРОПИЮ СВОЙСТВ ПОЛУЧАЕМОГО СЛИТКА

Abstract

The article presents theoretical substantiation of the influence of electroslag remelting technology with rotation of consumable electrode on physicomechanical properties of the formed casting (billet). The technology of electroslag remelting with rotation of consumable electrode around its own axis leads to formation of upward flow of heat in the slag bath, making hydrodynamic environment in mold more rational from the point of using generated heat. During rotation of consumable electrode, centrifugal forces act on liquid metal film formed at the end of the electrode, providing radial flow of molten metal droplets. Subsequent separation occurs from the outer perimeter of electrode. Thus, drops of electrode metal fall into the metal bath closer to the wall of the mold, aligning temperature front of the bath. Decrease in temperature gradient of bath over the cross section leads to a flatter crystallization front. Studied technology of electroslag remelting with rotation of consumable electrode should have an impact on physical and mechanical properties of resulting casting (billet). In order to establish effect of rotation of consumable electrode during electroslag remelting on properties of metal obtained, experimental remelting was carried out. The article presents data on experimental electroslag remelting of electrodes of 20Kh13 grade steel using various technologies at A-550 unit. In course of experiment, influence of rotation technology of consumable electrode on conditions of remelting process, billet crystallization, changes in mechanical and physical properties was established. The influence of remelting method on complex properties of resulting billet was analyzed. As the main research tool, processing of the obtained data on microhardness, density, dendritic cell size of experimental samples was used. Analysis of the research results of billets in transverse direction showed an increase in microhardness uniformity in implementation of electroslag remelting technology with rotation of consumable electrode along the course of smelting. It is also shown that use of the rotation technology reduces size of dendritic cell of billet and increases density of the ingot formed in comparison with traditional technology without rotating electrode.