Cleanliness improvement and microstructure refinement of H13 die steel by laboratory magnetic- controlled electroslag remelting

The current work investigated the impact of transverse static magnetic field (TSMF) with varied magnetic flux density (MFD) on cleanliness and microstructure of laboratory scale electroslag remelted H13 die steel. The inclusion morphology and microstructure evolution of electroslag remelted ingots were examined utilizing scanning electron and optical mi-croscopes, respectively. The number and size of inclusions in ingots were detected using the FEI Aspex Explorer. The results demonstrated that the number/size of inclusions in H13 electroslag remelted ingots were decreased as the MFD of applied TSMF increased. This resulted from the application of the TSMF, which produced the thinner liquid melting film (LMF), smaller droplets, and shallower metal molten pool, strengthening the kinetic con-ditions for inclusion migration to the slag-metal interface and the removal process. When the MFD of the applied TSMF was higher (95 mT and 140 mT), the LMF became thinner, the droplets became smaller, and the metal pool became shallower were more visible. More-over, the metal pool became shallower and the local solidification time became shorter after applying TSMF with larger MFD, resulting in finer dendritic structure and carbides. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study investigated the effects of transverse static magnetic field (TSMF) with varied magnetic flux density (MFD) on the cleanliness and microstructure of laboratory scale electroslag remelted H13 die steel. The results showed that the number and size of inclusions in H13 electroslag remelted ingots decreased as the MFD of applied TSMF increased, due to the thinner liquid melting film, smaller droplets, and shallower metal molten pool produced by the TSMF, which facilitated inclusion migration and removal.