Visualization Study on the Droplet Evolution Behaviors in Electroslag Remelting Process by Superimposing a Transverse Static Magnetic Field

摘要

A transparent experimental model had been built to visualize the electroslag remelting (ESR) process. With the help of the transparent model, the evolution of the droplet happening at the tip of the consumable electrode was recorded clearly by a high-speed camera with the record frequency of 200 frames per second. Firstly, the physical simulations were done under different intensities of the transverse static magnetic field (TSMF) with a constant remelting current of 8 A. Then the experiments were carried out at different intensities of the remelting current with a constant TSMF of 0.7 T. The representative processes of the droplet evolution under different conditions were demonstrated. When the external TSMF was large enough, a special phenomenon was discovered: The liquid neck connecting the end of the electrode with the droplet would become longer, and then an inflated liquid bulge appeared in the middle of the liquid neck. After a short while, the liquid metal neck was smashed into a lot of smaller droplets by the strong electromagnetic vibration. The results under different conditions indicated that the smashing effect acting on the droplet neck would be improved with the enlarging of the external TSMF at the constant remelting current, but it got worse under the condition of a higher remelting current. The mechanism of the smashing effect was well discussed.