Understanding the Dynamics of Vacuum Arc Remelting: Interaction Between Thermal Buoyancy and Lorentz Force

Vacuum Arc Remelting (VAR) is a metallurgical process employed to produce ingots with highly uniform chemical composition and minimal impurity levels. This paper investigates the influence of key process parameters, including arc type (diffusive arc, constricted arc) on flow dynamics and thermal behaviors within the molten pool of two different steel alloys with different thermal expansions. Numerical simulations demonstrate that variations in these parameters significantly affect the distribution of Electro-Vortex Flow (EVF) and thermal buoyancy flows inside the molten pool. The type of arc influences flow behavior: a diffusive arc leads to less intense electrovortex flows, while a constricted arc intensifies them, further impacting the pool depth. Additionally, higher thermal expansion coefficients favor thermal buoyancy, resulting in shallower pool depths, whereas lower coefficients enhance electrovortex flow strength, deepening the pool. Such insights enable engineers to optimize VAR operations for producing high-quality ingot, meeting industrial standards. This study underscores the critical role of parameter control in VAR processes to achieve superior material properties and minimize defects, contributing to advancements in metallurgical engineering.