Motion and removal behavior of inclusions in electrode tip during magnetically controlled electroslag remelting: X-ray microtomography characterization and modeling verification

Abstract

• Detailed 3D microtomography characterizations of inclusions in electrode tip are performed. • Motion/removal behavior of inclusions in electrode tip are clarified based on experimental results and simulation verification. • The number and size of the inclusions in LMF are decreased due to the applied ASMF. • The mechanism is that the ASMF enhances the kinetic conditions for inclusion migrating to LSI and removal in LMF. Detailed three-dimensional (3D) microtomography characterizations of inclusions in electrode matrix, mushy zone (MZ) and liquid melt film (LMF) were performed to elucidate the motion and removal behavior of inclusions in electrode tip during magnetically controlled electroslag remelting (MC-ESR) process. A transient 2D numerical model was also built to verify the experimental results and proposed mechanisms. The number and size of inclusions exhibited an obvious increasing trend from edge to mid region in LMF, while remained almost the same in electrode matrix and MZ. The inclusions in LMF migrated from edge to mid region of LMF, accompanied with removal process. In addition, the kinetic conditions for inclusion migrating to LMF/slag interface (LSI) were enhanced during MC-ESR process, thereby improving the inclusion removal efficiency in LMF. This work highlights the 3D characterization and motion/removal mechanisms of inclusions in electrode tip, as well as sheds new light on preparing high purity materials.