Application of orientation distribution functions' theory in the case of grain-oriented steels cut through classical and non-conventional technologies.

Grain-oriented silicon iron alloys present an important magnetocrystalline anisotropy, which has a strong influence on the normal magnetization curve and the energy losses. The theory of Orientation Distribution Functions (ODF), applied in the case of materials presenting crystalline symmetry of body centered cubic structure and orthorhombic strip symmetry, is taken into consideration. The magnetocrystalline anisotropy is analyzed on JFE Steel Corp. commercial grade M-0H grain-oriented electrical steel, cut at different angles with respect to the rolling direction, ranging from 0° to 90° in equal steps of 15°. The accuracy of the ODF method is analyzed by taking into account firstly three sets of experimental data, obtained for 0°, 45°, and 90°, then four sets, in the case of 0°, 30°, 60°, and 90° cut samples, and in the last case for all seven directions. The magnetic properties are predicted for any arbitrary direction and a relative error is analyzed, in each case, between the experimental and the numerical data. Finally, a proper number of experimental measurements was chosen, by considering a compromise between the magnitude of the error and the amount of experimental data. The samples were cut through mechanical punching, laser and travelling wire electro-erosion technologies. The normal magnetization curves and the energy losses were measured utilizing an industrial single strip tester (SST), at the frequency of 50 Hz. The model presented in the paper is a useful tool in the electric transformer cores' design since every magnetic property could be predicted with an increased accuracy in the case of each angle. [ABSTRACT FROM AUTHOR]