Structure of S45C Steel Solidified under the Simultaneous Imposition of a Static Magnetic Field and a Direct Current

S45C carbon steel has been solidified under the simultaneous imposition of a static magnetic field in vertical direction and a direct current having a horizontal component. Thus, an electromagnetic force was excited in the steel sample and it affected structure formation. Samples solidified under the different electromagnetic conditions were cut and chemically etched for the observation of the macro- and micro-structures. Solidified structure without the electromagnetic field was dendritic-structure. On the contrary, globular structure was obtained under the simultaneous imposition of the 1 T static magnetic field and the direct current of 20A in this experimental condition. The solidified structure was also globular structure, when the magnetic field intensity decreased to 0.3T. In the case only the 20A direct current was applied to the sample, dendritic structure and globular structure coexisted. For the modification of the solidified structure from dendritic structure to globular structure, the simultaneous imposition of the static magnetic field and the direct current is preferable to the simultaneous imposition of the static magnetic field and the alternating current from the viewpoint of the current intensity.