Abstract: Provided are: an oriented electromagnetic steel sheet with outstanding coating adhesion and magnetic properties after stress relief annealing; and a method for manufacturing the oriented electromagnetic steel sheet. The oriented electromagnetic steel sheet comprises: a steel sheet; a non-oxide ceramic coating disposed on the steel sheet and containing a non-oxide; and an insulating tensile coating disposed on the non-oxide ceramic coating and containing an oxide. The thickness of the non-oxide ceramic coating is 0.020-0.400 ?m. The thickness of the insulating tensile coating is at least 1.0 ?m. The chromium content on the steel plate side of the non-oxide ceramic coating is less than 25 atomic %, and the chromium content on the insulating tensile coating side of the non-oxide ceramic coating is at least 25 atomic %.

Abstract: To reduce variations in iron loss among materials subjected to magnetic domain refining by electron beam irradiation and to stably obtain good iron loss properties, disclosed is a method of producing a grain-oriented electrical steel sheet including performing magnetic domain refining treatment by irradiating with an electron beam, in a pressure reduced area, a surface of a grain-oriented electrical steel sheet after subjection to final annealing, the method further including: before the irradiating with the electron beam, delivering the grain-oriented electrical steel sheet wound in a coil shape and heating the delivered grain-oriented electrical steel sheet to 50° C. or higher; and then cooling the grain-oriented electrical steel sheet such that the grain-oriented electrical steel sheet has a temperature of lower than 50° C. at the time of entering the pressure reduced area.

Abstract: An excellent low noise property and excellent low iron loss property are obtained. A grain-oriented electrical steel sheet includes refined magnetic domains formed by electron beam irradiation. When the maximum magnetic flux density is 1.7 T, the grain-oriented electrical steel sheet has a residual magnetic flux density of 0.1 to 0.7 times the residual magnetic flux density before the electron beam irradiation and a maximum magnetizing force of 1.1 to 2.0 times the maximum magnetizing force before the electron beam irradiation.

Abstract: A grain-oriented electrical steel sheet exhibits reduced iron loss and reduced noise. The electrical steel sheet has magnetic domains refined by regions with a high lattice defect density being locally formed on the surface of or within the steel sheet, in which the regions with a high lattice defect density has a hardness, as measured by a micro Vickers hardness meter, equal to or lower than that of other regions.

Abstract: A grain-oriented electrical steel sheet, on which magnetic domain refining treatment by strain application has been performed, has an insulating coating with excellent insulation properties and corrosion resistance. The grain-oriented electrical steel sheet is obtained by irradiating a steel sheet with a high-energy beam to apply, to the steel sheet, linear strain extending in a direction that intersects a rolling direction of the steel sheet, and then re-forming an insulating coating on the steel sheet, in which in an irradiation mark region due to the high-energy beam, a ratio of an area containing defects on the insulating coating is 40% or less, a maximum width of the irradiation mark region in the rolling direction is 250 ?m or less, and a thickness of the insulating coating is 0.3 ?m or more and 2.0 ?m or less.

Abstract: A single roll type apparatus manufactures a metal thin strip by injecting a molten metal onto a cooling roll outer peripheral face solidifying it to manufacture the strip. An airflow blocking device for blocking the airflow along the cooling roll surface is at a molten metal injection nozzle upstream side for injecting the molten metal in the cooling roll rotation direction, and a carbon dioxide gas injection nozzle for forming a carbon dioxide flow on the cooling roll outer peripheral surface between the airflow blocking device and molten metal injection nozzle or forming a carbon dioxide atmosphere on the cooling roll surface between the airflow blocking device and the molten metal injection nozzle is disposed, and a foreign material removal device for removing foreign material attached to the cooling roll surface is disposed at an upstream side of the airflow blocking device in the rotation direction of the cooling roll.

Abstract: A steel sheet inspection device includes: a magnetooptic element that is able to detect, as an optical property, a magnetic domain structure of a steel sheet to be inspected; a light source that irradiates the magnetooptic element with linearly polarized light; a detector that detects the linearly polarized light with a polarization plane rotated according to the magnetic domain structure of the steel sheet transferred to the magnetooptic element; and a drive mechanism that drives at least the magnetooptic element so as to contact and separate the steel sheet and the magnetooptic element with and from each other.

Abstract: According to the present invention, a grain-oriented electrical steel sheet for iron cores exhibiting excellent transformer iron loss properties in an excitation range from 1.5 T to 1.9 T is provided, in which a residual stress of 150 MPa or more is formed near strain regions, each extending 300 ?m or less in the rolling direction and 42 ?m or more in the sheet thickness direction, and the strain regions are formed periodically at intervals of 2 mm to 10 mm in the rolling direction, with reduced energy loss in transformers in operation.

Abstract: Disclosed is a grain-oriented electrical steel sheet exhibiting low hysteresis loss and low coercive force, in which an increase in hysteresis loss due to laser irradiation or electron beam irradiation, which has been a conventional concern, is effectively inhibited. The grain-oriented electrical steel sheet has closure domain regions (X) formed to divide the magnetic domains in a rolling direction, from one end to the other in the width direction of the steel sheet, provided that Expression (1) is satisfied: ?(500t?80)×s+230?w??(500t?80)×s+330?? Expression (1), where t represents a sheet thickness (mm); w represents a smaller one of the widths (?m) of the regions measured on the front and rear surfaces of the steel sheet, respectively, by using a Bitter method; and s represents an average number of the regions present within one crystal grain.

Abstract: A grain-oriented electrical steel sheet to which electron beam irradiation is applied, has a film and a thickness of t (mm), wherein no rust is produced on a surface of the steel sheet after a humidity cabinet test lasting 48 hours at a temperature of 50° C. in an atmosphere of 98% humidity, and iron loss W17/50 after the electron beam irradiation is reduced by at least (?500 t2+200 t?6.5) % of the iron loss W17/50 before the electron beam irradiation and is (5 t2?2 t+1.065) W/kg or less.

Abstract: A linear groove formation method of forming linear grooves in a steel sheet surface using etching can form linear grooves of a uniform shape while suppressing a decrease in magnetic property of a grain-oriented electrical steel sheet caused by laser irradiation for resist removal. A linear groove formation method includes: coating a surface of a grain-oriented electrical steel sheet with a resist; performing a laser scan cyclically in a rolling direction of the grain-oriented electrical steel sheet, the laser scan being applying a laser while scanning the laser in a direction crossing the rolling direction to remove the resist in a portion irradiated with the laser; and etching the grain-oriented electrical steel sheet in each portion in which the resist is removed, to form a linear groove. A coating thickness of the resist is 0.5 ?m to 10 ?m, and a power of the laser is 1500 W or more.

Abstract: A grain-oriented electrical steel sheet allows for manufacture of a transformer that exhibits, when the steel sheet is applied to an iron core thereof, extremely low iron loss and extremely low noise properties, makes highly efficient use of energy, and can be used in various environments. The grain-oriented electrical steel sheet has a strain distribution in regions where closure domains are formed, when observed in a cross section in the rolling direction, with a maximum tensile strain in a sheet thickness direction being 0.45% or less, and with a maximum tensile strain t (%) and a maximum compressive strain c (%) in the rolling direction satisfying Expression (1): t+0.06?t+c?0.35??(1).

Abstract: The location where forsterite is present is checked in a region from which light excited by an electron beam is emitted when a material containing forsterite is irradiated with an electron beam. The material is preferably a grain oriented electrical steel sheet having a forsterite layer. In addition, it is preferable that the accelerating voltage be 10 kV or more when an electron beam is radiated when the material is a grain oriented electrical steel sheet having a tension coating layer on the forsterite layer.

Abstract: Disclosed are a grain-oriented electrical steel sheet having strain regions extending in a direction transverse to a rolling direction at periodic interval s (mm) in the rolling direction. Each strain region has a closure domain region whose width in the rolling direction varies periodically on a steel sheet surface. Each closure domain region satisfies: Wmax/Wmin=1.2 or more and less than 2.5, where Wmax and Wmin respectively denote a maximum width and a minimum width on the steel sheet surface as measured in the rolling direction; Wave being 80 ?m or more, where Wave denotes an average width on the steel sheet surface as measured in the rolling direction; D being 32 ?m or more, where D denotes a maximum depth as measured in the sheet thickness direction; and (Wave*D)/s being 0.0007 mm or more and 0.0016 mm or less.

Abstract: In a grain-oriented electrical steel sheet including: a steel substrate; a ceramic base film; and an insulating coating, critical damage shear stress ? between the base film and the steel substrate is 50 MPa or more. Thus, a grain-oriented electrical steel sheet having excellent insulation property, stacking factor, and magnetic property is provided without coating damage even when magnetic domain refining treatment by thermal strain is performed.

Abstract: A grain-oriented electrical steel sheet produces reduced noise when worked into a transformer, by setting length d of each plastic strain region in the widthwise direction of the steel sheet to 0.05 mm or more and 0.4 mm or less, and a ratio (?d/?w) of a total ?d of the length d to a total ?w of application interval w of each of the above plastic strain regions to 0.2 or more and 0.6 or less.

Abstract: Disclosed is a grain-oriented electrical steel sheet that exhibits excellent iron loss properties and a good building factor, in which damage to a tension coating is suppressed. In a grain-oriented electrical steel sheet having a tension coating, an interlaminar current is 0.15 A or less, a plurality of linear strain regions extending in a direction transverse to the rolling direction are formed, the strain regions are formed at line intervals in the rolling direction of 15 mm or less, each of the strain regions has closure domains formed therein, and each of the closure domains has a length d along the sheet thickness direction of 65 ?m or more and a length w along the rolling direction of 250 ?m or less.

Abstract: A grain oriented electrical steel sheet comprising a grain oriented electrical steel sheet having a surface and a forsterite film formed on the surface of the steel sheet, wherein a total area percentage of defective parts scattered on the forsterite film is less than 1.5% relative to a surface area of the forsterite film when viewed from above the surface, and methods for evaluating a grain oriented electrical steel sheet comprising a grain oriented electrical steel sheet having a surface and a forsterite film formed on the surface of the steel sheet.

Abstract: The present invention proposes a method that can reduce the noise generated by a transformer core and the like when formed by laminations of a grain-oriented electrical steel sheet in which core loss has been reduced by a magnetic domain refinement process. In this steel sheet, linear distortion extending with an orientation in which an angle formed with a direction perpendicular to the rolling direction of the steel sheet is an angle of 30° or less is periodic in the direction of rolling of the steel sheet, core loss (W17/50) is 0.720 W/kg or less, and magnetic flux density (B8) is 1.930 T. The volume of the closure domain arising in the distortion part is 1.00-3.00% of the total magnetic domain volume within the steel sheet.

Abstract: Provided is a grain-oriented electrical steel sheet including: a forsterite base film formed on a surface of the steel sheet; and an insulating tension coating formed on the base film, in which when Ti intensity FX(Ti), Al intensity FX(Al), and Fe intensity FX(Fe) obtained through quantitative analysis by performing fluorescent X-ray analysis on the surface of the steel sheet satisfy FX(Ti)/FX(Al)?0.15 and FX(Ti)/FX(Fe)?0.004, the frequency of crystal boundaries of secondary recrystallized grains in the direction orthogonal to the rolling direction is 20 grain boundaries/100 mm or less, the mean thickness of the forsterite base film t(Fo) and the thickness of the insulating tension coating t(C) satisfies t(Fo)/t(C)?0.3, and magnetic domain refining treatment is performed by irradiation with a laser beam, plasma flame, or electron beam, a sufficient iron loss reducing effect is achieved in a range where coating detachment does not occur.