A Novel Model for the Removal and Capture of Inclusions in Electroslag Remelting Process

Abstract

The cleanliness of steel is a critical factor influencing its corrosion resistance and mechanical properties. Electroslag remelting (ESR) technology has demonstrated excellent performance in removing inclusions from electroslag ingots. In general, four primary pathways exist for the removal and capture of inherited inclusions from the electrode in the ESR process. Current numerical simulation research typically focuses on modeling two or three of these pathways in ESR processes. This study, however, presents a highly accurate model that integrates the electromagnetic field with the flow field and heat transfer throughout the entire process of inclusion movement, removal and capture in ESR. To validate the accuracy of the model, a 2-ton industrial-scale ESR furnace was employed for the preparation of hot work tool steel H13. By comparing the metal droplet size in the residual electrode and the distribution of inclusions in the electroslag ingot as measured in industrial production, the ability of the model to predict the distribution of inherited inclusions from the electrode was confirmed. The results reveal that as the size of inclusions increases from 5 μm to 20 μm, the proportion of inclusions exuded from the liquid metal film decreases. Conversely, there is a significant increase in the proportion of inclusions that escape from the droplets and float up from the metal pool. Notably, the escape of inclusions from metal droplets accounts for a substantial proportion, exceeding ten percent. This stage is a crucial factor in industrial-scale models that cannot be overlooked.

Keywords: Electroslag remelting, inclusion removal, Heat transfer, electromagnetism