| 摘要 |
The present invention provides a method and a device to refine a magnetic domain of an oriented electrical steel sheet. According to the present invention, the method to refine the magnetic domain of an oriented electrical steel sheet comprises: a laser irradiation step of fusing a steel sheet by irradiating a laser beam to the steel sheet to form a groove part on a surface of the steel plate to form a groove based on fusion to have a depth, which is 4-10% of the thickness of the steel plate, by irradiating the laser beam accompanied by fusion regardless of the laser oscillating method and mode to the surface of the oriented electrical steel sheet before (after) a primary recrystallization is formed; and a brush step of performing a brush work using a rotating brush to remove a defect such as hill-up and spatter which forms on the groove part of the surface of the steel sheet by the irradiation of the laser beam in the laser irradiation step. The following formula (1) is satisfied, and a height of the defect of the groove part is maintained to have a maximum value of 2 μm or less; thereby reducing iron loss before/after heat treatment, and securing superior insulation and corrosion resistant characteristics. [Formula 1] D_p x 0.7 x (R_p-/R_a) <= 100, wherein D_p refers to a depth of the groove, and R_p and R_a refers to a height of a hill-up which is shown on the groove part after performing the brush step of brushing the groove part where a laser is irradiated, and intensity of illumination of the surface of a base part (a part without generation of a defect) after the brush step, respectively. |
