Morphology transition of eutectic carbide assisted by thermoelectric magnetic force during the directional solidification of M2 high-speed steel

Abstract

ABSTRACT The morphology of eutectic carbide was studied by application of a transverse static magnetic field (TSMF) during the directional solidification of M2 high-speed steel. The results show that the morphology of eutectic carbide changed from lamella to fibre as the magnetic flux density (MFD) increased from 0 to 1 T. The transformation from lamella to fibre has been enhanced by the increasing MFD. Solute elements moved and gathered at a certain region in the mushy zone when imposing a TSMF. In the mushy zones, channel segregations were formed in the samples treated by 0.2 and 0.4 T TSMF. When the MFD increased to 0.8 and 1 T, the channel segregation disappeared. Morphology transition, solute elements movement and formation of channel segregation were attributed to the thermoelectric magnetic force (TEMF). This work provides a new method to control the distribution of carbides in steel assisted by TEMF.