NONORIENTED MAGNETIC STEEL SHEET FOR HIGH-PERFORMANCE MOTOR

PROBLEM TO BE SOLVED: To provide a nonoriented magnetic steel sheet for high-performance motors, which can avoid a seizure between laminates even when a thickness of an insulating coating is thinned and, by increasing a space factor of a thin magnetic steel sheet, can reduce an iron loss at a high frequency.SOLUTION: A nonoriented magnetic steel sheet for high-performance motors that is a nonoriented magnetic steel sheet having a thickness of not larger than 0.20 mm and having an insulation film thickness of less than 0.8 μm, has an oxygen amount of a mother steel sheet surface from which an insulation film is removed of 100 ppm or higher and 600 ppm or lower, and may combine a high space factor and seizure prevention after stress relieving annealing. Even when the stress relieving annealing is applied, the seizure between the laminates may be avoided. By using the nonoriented magnetic steel sheet for high-performance motors of the present invention, a high-performance motor iron core having a high space factor of the steel sheet and excellent high frequency iron loss characteristics may be obtained.SELECTED DRAWING: Figure 1 【課題】絶縁コーティングの厚みを小さくしても積層間の焼付きを回避でき、薄手電磁鋼板の占積率を高めることにより、高周波での鉄損を低くできる高性能モータ用無方向性電磁鋼板を提供する。【解決手段】0.8μm未満の絶縁被膜厚を有する0.20mm厚以下の無方向性電磁鋼板であり、絶縁被膜を除去した母鋼板表面の[O]量が100ppm以上、600ppm以下である、高占積率と歪取り焼鈍後の焼付き防止を両立できる高性能モータ用無方向性電磁鋼板。歪取り焼鈍を施しても積層間の焼付きを回避できる。本発明の高性能モータ用無方向性電磁鋼板を用いることにより、鋼板の占積率が高い、高周波鉄損特性に優れた高性能モータ鉄心が得られる。【選択図】図１