Grain refinement of superalloy IN100 under the action of rotary magnetic fields and inoculants

The crystal structures of superalloy IN100 ingots under the action of rotary magnetic fields and inoculants were studied with the X-ray diffractometer and the optical microscope. The results indicate that the application of rotary magnetic fields and inoculants can refine the grain of γ matrix and increase the fraction of equiaxed grains. By initiating the 50 Hz and 150 A reversible electromagnetic stirring as soon as the molten metal was poured into the mould, which was coated with inoculant CoAl2O4, the average equiaxed grain size of IN100 superalloy ingots can be refined to 95 μm and the fraction of equiaxed grains can be increased to 100%. The mechanisms of the grain refinement and the increment in the equiaxed fraction were proposed. The effect of the inoculant on the crystal structures of superalloy IN100 ingots was studied.