High magnetic field iron loss and super high flux density one side where it is superior in coat property tropistic electromagnetic steel sheet

摘要

PROBLEM TO BE SOLVED: To provide a unidirectional electromagnetic steel sheet with an ultrahigh magnetic flux density and excellent in high-magnetic-field core loss and coating film characteristics.;SOLUTION: The unidirectional electromagnetic steel sheet has the following features: the Si content is 2-7 mass%; in observing the cross section of the surface of a steel sheet composed of a primary coating film and base metal, a Mg-containing internal oxide with an equivalent circle diameter of 0.1 μm or more is observed in the range of from the surface to a depth of 10 μm; the wedge ratio is 10% or higher; since Bi in a content of 0.01 mass ppm or higher but lower than 1,000 mass ppm is present at the interface between base metal and the primary coating film, the ratio: W_19/50/W_17/50 of W_19/50 (energy loss under the excitation conditions of 1.9T and 50 Hz) to W_17/50 (energy loss under excitation conditions of 1.7T and 50 Hz) is less than 1.8; and in bending to a curvature radius of 30 mm, the coating film separation occurs at a ratio lower than 25%.;COPYRIGHT: (C)2004,JPO&NCIPI