PREPARATION OF NO SILICON STEELS WITH COLUMNAR MICROSTRUCTURE AND LOW WATT LOSSES

František Kováč – Ivan Petryshynets – Viktor Puchy – Martin Šebek – Jozef Maruš

   In the present work, we have used an adjusted temper rolling process for development of particular textures {100}<0vw> in vacuum degassed non-oriented silicon steels. The main idea behind the improvement of soft magnetic properties relies on deformation induced grain boundary motion and heat transport phenomena through the cross-section of sheet plane promoting the preferable formation of columnar or huge grains with desired orientation. The vacuum degassed non-oriented steel with silicon content 1.3% wt was taken from industrial line after final annealing. The columnar microstructure with pronounced intensity of cube and Goss texture components in the investigated non-oriented steel was achieved by using deformation induced growth of ferrite grains during the continuous final annealing at dynamic conditions. This thermal treatment was carried out at the laboratory furnace with the heating rate of Vh 25°C/s and cooling rate of Vc 7°C/s. The electron backscatter diffraction was used to determine the crystallographic orientations of grains with respect to individual rolling planes and rolling directions. The magnetic measurements demonstrated that the watt losses of investigated steels treated by suggested approach were decreased from 9.7 W/kg to 6.5 W/kg.

Keywords: :silicon steel, magnetic isotropy, watt losses, texture analysis

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