Abstract
The formation and dripping behavior of droplets in the process of the electroslag remelting with two series-connected electrodes (TSCE-ESR) has an important influence on the optimization of power supply parameters and the purity of the electroslag ingot. In this article, through numerical simulation based on the VOF (volume of fluid) model, combined with the transparent experimental device for physical simulation, the mechanism of metal droplet formation and the effect of the filling rate on its droplet behavior were studied. The results showed that the proximity effect, instead of the skin effect, is a major factor influencing droplet formation in TSCE-ESR process. The proximity effect makes the region inside the two electrode tip melt first, and the molten steel converges at the electrode tips to form a droplet source. The process of droplet formation and dropping can be divided into three stages: formation of molten layer, droplet stretching and necking, and detachment. In the stage of droplet stretching and necking, the increase in the contact area between the droplet and the slag and the instantaneous increase of the current provide good thermodynamic and dynamic conditions for the removal of non-metallic inclusions. After the droplet drops into the slag pool, it promotes the flow of slag and improves the heat and mass transfer efficiency of the slag/metal interface. The relatively large filling rate can form smaller and dispersed droplets, which improves the refining effect. At the same time, the increase of the filling rate can improve the input power and the electrode remelting rate.
Highlights
Electroslag remelting (ESR) can effectively improve the cleanliness and compactness of steel and is widely used in the production of high-quality steel and alloys
In the process of droplet formation and dripping, the molten metal and the slag are fully contacted, and the contact area and time are much larger than the traveling time of the droplet in the slag pool, so the electrode tip is the main area for slag/metal reaction and non-metallic inclusion removal [1]
Due to the high temperature and the opacity of the metal phase, it is difficult to observe the phenomenon of metal droplets in the slag in the actual process of ESR, so only numerical simulation or physical simulation can be used for research
Summary
Electroslag remelting (ESR) can effectively improve the cleanliness and compactness of steel and is widely used in the production of high-quality steel and alloys. ElGammal [11] used NaCl solution to remelt the low melting point alloy All these works studied the influence of slag composition and height [12], interfacial tension [5], current density [13,14], consumable electrode shape [15], current frequency [9,16], and other factors on droplet formation. Under the condition of satisfying the electromagnetic effect, the change of velocity field and temperature field in the slag pool can be studied by the method of numerical simulation when the drops fall. The distribution of the flow field and temperature field in the slag pool was obtained through steady state calculation as the initial condition of the electrode melting model in the numerical simulation. The influence of filling rate on droplet formation and the dropping process was studied, which provided a theoretical basis for improving the quality of ingot in TSCE-ESR
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
