PHYSICAL MODELING OF THE TRAJECTORY OF ELECTRODE METAL DROPLETS DURING HOLLOW INGOT PRODUCTION BY ELECTROSLAG REMELTING

Abstract

The paper investigates the electroslag remelting (ESR) process using a single-electrode configuration with a piercing mandrel for the production of hollow ingots. The primary challenge of this technology is the adhe-sion of molten electrode metal droplets onto the mandrel tip, which disrupts the formation of a hole with the desired geometry. To address this issue, rotation of the consumable electrode about its own axis is proposed, enabling redistribution of the liquid metal flow through centrifugal forces. The expe-rimental study was conducted using physical modeling, employing Wood’s alloy (to simulate metal) and glycerin (to simulate the slag bath), thereby ensuring similarity criteria compliance with the actual industrial process. It was found that at rotation speeds of 290–340 rpm, centrifugal forces redirect the metal flow ra-dially, transforming the electrode’s melting surface from conical to flat. This prevents droplet contact with the mandrel, channeling the metal into the annular gap between the mandrel and the mold. Concurrently, an inversion of slag flow patterns (from downward to upward) and a shift in the current path within the pool beneath the electrode were observed, resulting in reduced thermal loading on the mandrel. The exper-iments validated the analytical relationship for calculating the optimal rotation speed, which accounts for the system’s geometric parameters. The study demonstrated that electrode rotation reduces droplet mass by more than half at moderate speeds. However, excessive rotation rates (e.g., 500 rpm) lead to the for-mation of a concave electrode surface and an increase in droplet volume. These findings confirm the feasibility of controlling the thermal center of the slag pool, thereby enhancing the competitiveness of the single-electrode ESR configuration compared to multi-electrode alternatives. The proposed technology reduces electrode manufacturing costs while maintaining ingot quality and offers promising prospects for industrial implementation.