Nippon Steel Corporation

Masato Mizokami

Hisashi Mogi

Fumiaki Takahashi

Masahiro Fujikura

Satoshi Arai

Takeshi Kubota

Kenichi Murakami

Hideyuki Hamamura

Shinji Yamamoto

Masaru Takahashi

Takahito Mizumura

Masao Yabumoto

Yoshiyuki Ushigami

Hiroyasu Fujii

Shuichi Yamazaki

Osamu Akisue

Norikazu Fujii

Hirofumi Imai

Shingo Okada

Shinya Hayashi

Akira Sakaida

Hideyuki Kobayashi

Eisuke Minematsu

Toshihiko Uemura

Yoichi Zaizen

When joining end faces of a plurality of soft magnetic sheets which are superposed in the sheet thickness direction and which are bent at parts forming corner areas of a core, offset of positions of the end faces from the desired positions is suppressed. In a region of a window part comprised of a region inside of a first partand second part, a third partwith a length in a longitudinal direction (X-axial direction) the same as a length in the X-axial direction of the window part at the position where the third partis arranged is arranged so as to contact the region of the inner circumferential surface between the first corner areaand third corner area

Magnetic core

Provided is a wound core formed by laminating a plurality of bent bodies obtained by forming a coated grain-oriented electrical steel sheet in which a coating is formed on at least one surface of a grain-oriented electrical steel sheet so that the coating is on an outside, in a sheet thickness direction, in which the bent body has a bent region obtained by bending the coated grain-oriented electrical steel sheet and a flat region adjacent to the bent region, the number of deformation twins present in the bent region in a side view is five or less per 1 mm of a length of a center line in the sheet thickness direction in the bent region, and when a region extending 40 times a sheet thickness to both sides in a circumferential direction from a center of the bent region on an outer circumferential surface of the bent body is defined as a strain affected region, a proportion of an area where the coating is not damaged at any position along the circumferential direction in a flat region within the strain affected region is 90% or more.

Wound core and method for producing same

A grain-oriented electrical steel sheet according to the present invention includes a silicon steel sheet as a base steel sheet, and when an average value of amplitudes in a wavelength range of 20 to 100 &#x3bc;m among wavelength components obtained by performing Fourier analysis on a measured cross-sectional curve parallel to a sheet width direction of the silicon steel sheet is set as ave-AMP, ave-AMPis 0.0001 to 0.050 &#x3bc;m.

Grain-oriented electrical steel sheet and method of producing the same

A wound core is formed by laminating a plurality of bent bodies formed from a grain-oriented electrical steel sheet having a coating containing phosphorus formed on a surface, in a sheet thickness direction of the grain-oriented electrical steel sheet, in which the bent body is formed in a rectangular shape by having four flat portions and four corner portions adjacent to the flat portions, the corner portion has a bent region having a total bending angle of approximately 90&#xb0; in a side view, the number of deformation twins present in the bent region in the side view is five or less per 1 mm of a length of a center line in the bent region in the sheet thickness direction, and the amount of phosphorus eluted from the corner portion in a case of being boiled in water for 30 minutes is 6.0 mg or less per 1 mof a surface area of the corner portion.

Wound core and manufacturing method thereof

A grain-oriented electrical steel sheet comprising a steel sheet having a surface on which grooves, in which an extending direction crosses a rolling direction and a depth direction is parallel to a sheet thickness direction, are formed, and wherein a molten solidified substance ranging in parallel to the groove exists on both sides of the groove on the surface of the steel sheet, and a height becoming a maximum frequency in a height distribution of height data in which the surface of the steel sheet in a specific area including the groove is measured at regular intervals is set as a virtual plane, and a value of V2/V1 is more than 0.10 and less than 0.80, wherein V1 is a space volume of recess parts recessed from the virtual plane and V2 is a volume of projection parts projected from the virtual plane.

Grain-oriented electrical steel sheet

A grain-oriented electrical steel sheet includes: a base steel sheet; a primary film formed on a surface of the base steel sheet; and a tension insulation coating formed on a surface of the primary film, in which a magnetic domain control is performed by irradiating the tension insulation coating with a laser from above. When a strip-like sample having a length of 300 mm in a direction parallel to a rolling direction of the grain-oriented electrical steel sheet and a length of 60 mm in a direction parallel to a transverse direction is extracted from the grain-oriented electrical steel sheet, a range from a surface of the tension insulation coating to a depth position of 5 &#x3bc;m toward the base steel sheet side from an interface between the base steel sheet and the primary film is removed by pickling at least one surface of the sample, and a warpage amount of the sample is thereafter measured, the warpage amount satisfies predetermined conditions.

Grain-oriented electrical steel sheet causing low core loss and low magnetostriction

The present invention provides an electrical steel sheet core for a low-noise transformer capable of effectively lowering noise by suppressing vibration perpendicular to the surfaces of the steel sheets and reducing vibration, and relates to an electrical steel sheet for a low-noise transformer characterized by randomly inserting viscoelastic layers with both viscosity and elasticity into the gaps of the steel sheet lamination layers, and a low-noise transformer formed by using said electrical steel sheet.

Electrical steel sheet for low-noise transformer and low-noise transformer

The object of the present invention is to provide a low iron loss and low noise grain-oriented electrical steel sheet for securing both low core loss and low noise of a transformer at the same time. The present invention relates to a grain-oriented electrical steel sheet containing Si: 1.0-4.0 wt % produced by controlling, with regard to &#x3b5;, which is defined as a 0-p value when a grain-oriented electrical steel sheet is magnetized up to a saturated magnetic flux density, and &#x3b5;, which is defined as the value obtained by subtracting a 0-p value at the magnetization magnetic flux density of 1.7 T from a 0-p value at a saturated magnetic flux density, &#x3b5;and &#x3b5;, which are absolute values deviated by forming a tension film and a forsterite film, and &#x3b5;and &#x3b5;, which are absolute values deviated by irradiating laser after the film formation, in adequate ranges respectively, and further controlling &#x3bb;, which is a 0-p value at the magnetization magnetic flux density of 1.7 T, in the most appropriate range, when measuring a 0-p value of magnetostriction vibration in the rolling direction.

Low iron loss and low noise grain-oriented electrical steel sheet and a method for producing the same

The object of the present invention is to provide a low iron loss and low noise grain-oriented electrical steel sheet for securing both low core loss and low noise of a transformer at the same time. The present invention relates to a grain-oriented electrical steel sheet containing Si: 1.0-4.0 wt % produced by controlling, with regard to &egr; , which is defined as a 0-p value when a grain-oriented electrical steel sheet is magnetized up to a saturated magnetic flux density, and &egr; , which is defined as the value obtained by subtracting a 0-p value at the magnetization magnetic flux density of 1.7 T from a 0-p value at a saturated magnetic flux density, &egr; and &egr; , which are absolute values deviated by forming a tension film and a forsterite film, and &egr; and &egr; , which are absolute values deviated by irradiating laser after the film formation, in adequate ranges respectively, and further controlling &lgr; , which is a 0-p value at the magnetization magnetic flux density of 1.7 T, in the most appropriate range, when measuring a 0-p value of magnetostriction vibration in the rolling direction.

The present invention provides a grain-oriented electrical steel sheet, for a low noise transformer, capable of reducing higher harmonics which are highly audible and lowering noise effectively, and relates to a grain-oriented electrical steel sheet for a low noise transformer, characterized by imposing a film tension of 0.5 to 6.0 MPa on the surface by coating or a method corresponding thereto, without forming a glass film on the grain-oriented electrical steel sheet or, if a glass film is formed, after removing the glass film by an arbitrary method.

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Tokyo, Japan

Masato Mizokami