The Effect of Current Intensity on Macrosegregation in Vacuum Arc Remelting Cr14Mo4V Ingot Based on a Three‐Phase Mixed Columnar‐Equiaxed Model

Vacuum arc remelting (VAR) is the main process for preparing Cr14Mo4V. Due to its ultra‐high temperature and invisibility, the development of this process is extremely difficult. This study developed a two‐dimensional axisymmetric three‐phase model based on the Euler method to predict macroscopic segregation phenomenon of Cr14Mo4V ingots during VAR process. This model has undergone multiple experimental comparisons to determine its accuracy. The results indicate that the flow field inside the melt pool is mainly composed of vortices driven by Lorentz forces and thermal solute buoyancy. Increasing the current intensity will cause excessive concentration of equiaxed phases towards the center of the ingot, reducing its radial distribution. The core of the ingot exhibits negative segregation and the edges exhibit positive segregation, with the transition occurring approximately at half the radius of ingot. When the current intensity increases from 6200 A to 8000 A and 10 000 A, the macrosegregation of the ingot in both axial and radial directions intensifies. In addition, when the current is 10 000 A, the flow field loses stability and segregation channels appear near the hot top period. Overall, both the solidification structure and composition distribution of the ingot under a melting current of 6200 A exhibit higher uniformity.