PURPOSE: To obtain a directional electrical steel sheet with superior magnetic characteristics by irradiating the surface of an electrical steel sheet subjected to finish annealing with laser light having specified energy, and carrying out strain relieving annealing at a specified temp.
CONSTITUTION: The surface of an electrical steel sheet subjected to finish annealing is irradiated with laser light having ≥1 J/cm2 energy (u), and the width of magnetic domains at both sides of the irradiated strain region is subdivided to reduce the iron loss. The steeL sheet having traces of the irradiation with laser light is optionally flattened at about 700W900°C, and it is annealed at 600°C and treated to form an insulating film. By this method residual stress is relieved, and a directional electrical steel sheet with superior magnetic characteristics is obtd.
INOUCHI TOORU
NAKAMURA MOTOHARU
HIROSE KIKUJI
ISHIMOTO TADASHI
| JPS56123325A | 1981-09-28 |
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