Numerical simulation of molten fluid behavior during vacuum arc remelting process

Vacuum arc remelting (VAR) is one of the principal secondary remelting technologies for producing titanium alloys, nickel-based superalloys and other high-value added alloys due to many advantages such as lower cost, higher efficiency and easier to operate, but there are still some problems resulting in structure defects and inhomogeneous component in VAR ingots. Therefore, it is crucial in controlling the fluid behavior in molten pool during the whole process, which has the direct relationship with the metallurgical structure and the component of ingots. The VAR process involves complex interactions of the electromagnetic, flow, and heat transfer processes, which have important effect on the fluid behavior in the molten pool. Mathematical modeling is a scientific and cost-effective approach for developing a fundamental understanding of the governing physical processes and predicting the effects of various operating parameters on process performance. This article describes a model of the VAR process that includes electromagnetic, temperature field and fluid field with ANSYS software. The results indicate that the fluid zone is determined mainly by the temperature field. The fluid orientation is decided by the competition of buoyancy forces and Lorentz forces. The parameters such as remelting current and melt rate also been discussed in the present paper.