| 摘要 |
PURPOSE:To manufacture a grain-oriented silicon steel sheet free from deterioration in iron loss characteristics at the time of stress relief annealing by locally removing an oxide layer from one side of a grain-oriented silicon steel sheet after secondary recrystallization annealing by means of ultrasonic energy scanning using plural ultrasonic vibrators while moving the above sheet in a stretched state. CONSTITUTION:A grain-oriented silicon steel sheet 1 after secondary recrystallization annealing is laid on a rotating cylindrical roller 2 and moved in the direction of an arrow. A head 4 in which plural ultrasonic vibrators 5 are disposed in a manner to be opposed to one side, of the steel sheet 1, free from contact with the roller 2 and kept in a stretched state is allowed to perform a reciprocating motion in a direction perpendicular to the longitudinal direction of the steel sheet 1 by means of spindles 6 rotating by means of a motor 7 and repeatedly scanned across the surface of the steel sheet 1 into the state of plural lines according to the number of the ultrasonic vibrators 5, by which an oxide film in the scanned part is partly removed. By this method, the grain-oriented silicon steel sheet reduced in iron loss and free from deterioration in magnetic properties at the time of stress relief annealing can be manufactured at a low cost. |
