Morphology Control of Metal Pool and Eutectic Carbides in Electroslag Remelted M2 HSS with an External Axial Static Magnetic Field

Abstract

This study investigates the influence of a superimposed axial static magnetic field (ASMF) on the morphology of metal pool and eutectic carbides (ECs) in electroslag remelted M2 high-speed steel (HSS). The application of ASMF caused the metal pool to become shallower, and the solidified structure to expand axially, along with finer (i.e., more uniformly distributed and crystallographically oriented) ECs. Lorentz force-driven unidirectional circulation in slag pool was the primary cause of the metal pool’s morphological adjustment; this resulted in a more homogenous temperature distribution in slag pool. Thus, the heat transfer from the slag pool to the metal pool became more uniform, creating a metal pool that is shallower. Additionally, local solidification time (LST) became shorter, while the number of (Ti, V)N-Al2O3 inclusions serving as heterogeneous nuclei for EC formation increased due to ASMF, enabling finer EC with more crystallographic orientations in ESR ingots.