Jfe Steel Corporation

Kawasaki Steel Corporation

Kunihiro Senda

Michiro Komatsubara

Toshito Takamiya

Masanori Uesaka

Yoshihiko Oda

Takeshi Omura

Mitsumasa Kurosawa

Hiroaki Toda

Seiji Okabe

Yoshiaki Zaizen

Hirotaka Inoue

Atsuhito Honda

Souichiro Yoshizaki

Makoto Watanabe

Yoshihisa Ichihara

Tomoyuki Okubo

Hiroi Yamaguchi

Yukino Miyamoto

Takafumi Suzuki

Tetsuo Toge

Kenichi Sadahiro

Yasuhito Shioiri

Masayoshi Ishida

Yoshihide Kamitani

Takashi Terashima

Yasuyuki Hayakawa

Shigehiro Takajo

Yukihiro Shingaki

Mineo Muraki

Tadashi Nakanishi

Takahiro Koshihara

Kazuaki Tamura

Kazuhiro Suzuki

Michiro Komatubara

Seiji Sato

Chizuko Goto

Provided is a non-oriented electrical steel sheet having excellent adhesion with an insulating coating even if the thickness of the insulating coating is reduced. The non-oriented electrical steel sheet of the present disclosure has an insulating coating on at least one surface of the steel sheet, where the insulating coating has a P-concentrated layer on both a surface side and an interface side with a steel substrate, and a P concentration of the P-concentrated layer is higher than a P concentration in the steel substrate.

Non-oriented electrical steel sheet and method for manufacturing same

A method for manufacturing a motor core includes a step of manufacturing a motor core by performing melt-cutting on an electrical steel sheet using heat input from a surface, the electrical steel sheet having an average thermal conductivity in depth positions from the surface to one-third depth of a sheet thickness lower than a thermal conductivity in a middle position in a sheet thickness direction by 30% or greater.

Method for manufacturing motor core

Provided is a linear groove formation pattern with which both an effect of reducing the building factor and a high magnetic flux density can be obtained. In a grain-oriented electrical steel sheet having a plurality of linear grooves extending in a direction crossing a rolling direction of the steel sheet on a surface of the steel sheet, a surface of the steel sheet between the linear grooves has a recessed defect that is recessed from the surface, a volume fraction of the recessed defect in the steel sheet is 0.0025 vol % or more and 0.01 vol % or less of a steel sheet without the recessed defect, and discontinuous portions that disrupt the extension of the linear grooves are provided at a frequency of 30 or more and 200 or less per square meter of the steel sheet.

Grain-oriented electrical steel sheet

Disclosed is a grain-oriented electrical steel sheet with extremely low iron loss by means of a magnetic domain refining technique. In a grain-oriented electrical steel sheet having a plurality of magnetic domains refined via a local strain introduction portion, when a direct-current external magnetic field is applied to the steel sheet in a rolling direction, for a magnetic flux leaked from the local strain introduction portion at a position 1.0 mm away from a surface of the steel sheet at a side of the local strain introduction portion, a value obtained by dividing an intensity level of a total leakage magnetic flux by an intensity level of a magnetic flux leaked due to causes other than strain is more than 1.2.

Grain-oriented electrical steel sheet and method of producing same

Provided is a grain-oriented electrical steel sheet that combines low iron loss and low magnetostriction, together with an advantageous production method therefor. A grain-oriented electrical steel sheet comprises a linear strain portion extending in a direction intersecting a rolling direction of the grain-oriented electrical steel sheet, wherein the linear strain portion has a stress distribution in which a compressive stress region and a tensile stress region alternate in a longitudinal direction of the linear strain portion. The linear strain portion is formed by vibrating the grain-oriented electrical steel sheet in a sheet thickness direction, while irradiating a surface of the grain-oriented electrical steel sheet with an electron beam by repeatedly moving and detaining the electron beam in the direction intersecting the rolling direction of the grain-oriented electrical steel sheet.

Grain-oriented electrical steel sheet and production method therefor

Provided is a grain-oriented electrical steel sheet having better transformer iron loss property than conventional grain-oriented electrical steel sheets. A grain-oriented electrical steel sheet comprises: a steel substrate; a forsterite film on a surface of the steel substrate; and a Cr-depleted layer at a boundary between the steel substrate and the forsterite film, the Cr-depleted layer having a Cr concentration that is 0.70 times to 0.90 times a Cr concentration of the steel substrate.

Grain-oriented electrical steel sheet and method for manufacturing same

A motor comprising a steel sheet used as a core material of the motor, wherein the steel sheet includes a composition including: by mass %, 0.010% or less of C; 2.0% to 7.0% of Si; 2.0% or less of Al; 0.05% to 1.0% of Mn; 0.005% or less of S; 0.005% or less of N; and balance Fe and inevitable impurities; the steel sheet includes a magnetic flux density changing area where a change &#x394;B in magnetic flux density to a change &#x394;H=50 A/m in a magnetic field, is equal to or higher than 0.50 T; a thickness of the steel sheet is 0.05 mm to 0.20 mm; and an eddy-current loss of the steel sheet, at 1000 Hz&#x2212;1.0 T, is equal to or less than 0.55 of a total iron loss.

Motor

Further lower iron loss can be achieved in a grain-oriented electrical steel sheet including: a predetermined film mainly composed of forsterite on a front and back surfaces thereof; and a plurality of grooves on the front surface thereof, in which the plurality of grooves have an average depth of 6% or more of a thickness of the steel sheet and are spaced a distance of 1 mm to 15 mm from respective adjacent grooves, the steel sheet has a specific magnetic permeability &#x3bc;rof 35000 or more when subjected to alternating current magnetization at a frequency of 50 Hz and a maximum magnetic flux density of 1.5 T, and the steel sheet includes isolated parts having a presence frequency of 0.3/&#x3bc;m or less, the isolated parts being separated from a continuous part of the film in an interface between the steel sheet and the film in a cross section orthogonal to the rolling direction of the steel sheet.

A method of manufacturing a laminated iron core includes: inserting a plurality of electrical steel strips in a superposed state to feed rolls including a pair of upper and lower feed rolls that are driven by a drive device to feed the electrical steel strips in a superposed state into a die having a plurality of punching processes in sequence; joining a part or all of the superposed electrical steel strips together before entering the die or at an upstream stage portion of the die after feeding out the electrical steel strips from the pair of upper and lower feed rolls; and punching simultaneously the plurality of electrical steel strips in a superposed state in the die.

Method of manufacturing laminated iron core

A non-oriented electrical steel sheet has low iron loss even under inverter excitation and can be suitably used as the iron core of a motor. The non-oriented electrical steel sheet has a specific chemical composition and an average grain size r of 40 &#x3bc;m to 120 &#x3bc;m. An area ratio R of a total area of grains having a grain size of &#x2159; or less of the thickness of the steel sheet to a cross-sectional area of the steel sheet is 2% or greater, and the average grain size r (&#x3bc;m) and the area ratio R (%) satisfy a condition represented by Expression (1), R&#x3e;&#x2212;2.4&#xd7;r+200 (1).

Non-oriented electrical steel sheet and method for manufacturing non-oriented electrical steel sheet

A punch processing method for electrical steel sheets to manufacture core segments includes: stacking a plurality of electrical steel sheets; and punching out the plurality of electrical steel sheets in a stacked state simultaneously to manufacture the core segments, wherein in a case where the core segments are applied to a stator core in which a maximum magnetic flux density at a tooth portion is to be higher than a maximum magnetic flux density at a back yoke portion, degrees of Vickers hardness of an electrical steel sheet located second from a bottom side and above in the stacked state are set to 180 HV or higher, and 10 HV or higher than a value of degree of Vickers hardness of an electrical steel sheet located on the bottom side in the stacked state.

Punch processing method for electrical steel sheets and method for manufacturing laminated core

A material for laminated iron cores is used as plural steel sheets to be overlapped with one another and punched when a laminated iron core is manufactured. A surface roughness of the steel sheets forming the material for laminated iron cores is at an arithmetic mean roughness Ra of 0.40 [&#x3bc;m] or less, and a sheet thickness deviation in a sheet width direction of at least a portion used as the laminated iron core is 3 [&#x3bc;m] or less per 500 [mm], the portion being of the steel sheets forming the material for laminated iron cores.

Material for laminated iron core, and method of manufacturing laminated iron core

A punching method includes: punching out a plurality of electrical steel sheets in a stacked state by a mold, wherein sheet thicknesses of the electrical steel sheets are set to be 0.35 mm or less, a Vickers hardness (test force 1 kg) of the sheets is set to be 150 to 400, and an average crystal grain size of the sheets is set to be 50 to 250 &#x3bc;m, a clearance of the mold is set to be 7% or more of a minimum sheet thickness of the sheet thicknesses of the electrical steel sheets and equal to or lower than 7% of a total sheet thickness of the electrical steel sheets, and a pressure that a sheet presser of the mold applies to the electrical steel sheets is set to be 0.10 MPa or more.

Punching method, punching device, and method for manufacturing laminated iron core

A Laminated core manufacturing device includes: an overlapping unit configured to overlap the plurality of laminated core materials conveyed along different conveyance routes; an edge aligning unit configured to align edge positions in a width direction of the plurality of laminated core materials between the plurality of laminated core materials; an uplift prevention unit configured to prevent uplift of the plurality of laminated core materials; an edge position correction unit configured to correct the edge positions in the width direction of the plurality of laminated core materials; and a punching unit configured to punch out the plurality of laminated core materials which are overlapped by the overlapping unit and have been subjected to an edge position alignment process performed by the edge aligning unit, an uplift prevention process performed by the uplift prevention unit, and an edge position correction process performed by the edge position correction unit.

Laminated core manufacturing apparatus and laminated core manufacturing method

A laminated core manufacturing device includes: an overlapping unit configured to overlap the plurality of laminated core materials conveyed along different conveyance routes; an edge position correction unit configured to align edge positions in a width direction of the plurality of laminated core materials between the plurality of laminated core materials and to correct shift of each edge position of the plurality of laminated core materials with respect to a standard edge position; an uplift prevention unit configured to prevent uplift of the plurality of laminated core materials; and a punching unit configured to punch out the plurality of laminated core materials which are overlapped by the overlapping unit and have been subjected to a process to align the edge positions and to correct shift of the edge positions performed by the edge position correction unit, and a process to prevent the uplift performed by the uplift prevention unit.

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Tokyo, Japan

Kunihiro Senda