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

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.

KEYWORDS:

• M2 high-speed steel
• eutectic carbide
• thermoelectric magnetic force
• segregation
• microhardness
• directional solidification
• microstructure
• ransverse magnetic field

Acknowledgements

This work was supported by the National Key Research and Development Program of China [2016YFB0300401, 2018YFF0109404]; the National Natural Science Foundation of China [U1860202, U1732276, 51904184, 51704193, 52004156]; Users with Excellence Program of Hefei Science Center CAS (2019HSC-UE010); Changjiang Scholars Program of China.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Joint Fund of Iron and Steel Research: [grant number U1860202]; Joint Fund of Research utilising Large-scale Scientific Facilities: [grant number U1732276]; National Key Research and Development Program of China: [grant number 2016YFB0300401]; National Key Research and Development Program of China: [grant number 2018YFF0109404]; Young Scientists Fund: [grant number 51904184]; Young Scientists Fund: [grant number 51704193]; Young Scientists Fund: [grant number 52004156].