Effect of magnetic field on solidification structure of a centrifugal cast high speed steel roll

The electromagnetic field exerted during solidification of a centrifugal cast high speed steel roll causes a marked variation in the structure. The type, size, distribution and volume fraction of carbides change with increasing magnetic field intensity. The appropriate external magnetic field (0•15 T in the present study) can refine carbides, break down carbides' network on grain boundaries, make some carbides form in grains, distribute carbides more homogeneously on grain boundaries or in grains and improve overall bulk hardness. The application of external magnetic field can also refine grains, reduce retained austenite and improve matrix hardness. It can be expected that through inducing an appropriate external magnetic field during centrifugal casting these changes can give an improvement of properties of HSS rolls, such as wear resistance and thermal fatigue properties. © 2010 Institute of Materials, Minerals and Mining.