| 摘要 |
PROBLEM TO BE SOLVED: To obtain a wound core in which an interlayer short circuit at a laminated layer face is suppressed effectively by a method wherein the thickness per face of a surface-layer oxide layer on a steel strip is specified at the laminated-layer face after a straightening annealing operation. SOLUTION: The thickness per face of a surface-layer oxide layer on a steel tape at a laminated-layer face after a straightening annealing operation is set at about 10% or lower of the plate thickness of the steel strip. In addition, the depth in the plate-width direction of the steel strip of the surface-layer oxide layer on the steel strip at the laminated-layer face after the straightening annealing operation is set within about 5mm from the edge of the steel strip. As a blank for a wound core, an iron-based grain-oriented magnetic steel sheet, a nonoriented magnetic steel sheet, an amorphous sheet or the like is used. The wound core after the straightening annealing operation may be impregnated with a varnish as it is in a next process. However, plate edge parts at a laminated-layer face are deviated alternately to both sides, and an interlayer short circuit at the laminated-layer face is removed as far as possible. In addition, also a burr is taken into consideration. Thereby, it is possible to manufacture the wound core in which a core loss is low, in which an irregularity in a core loss value is small and which has a stable core loss characteristic. |
