Jfe Steel Corporation

Shigehiro Takajo

Seiji Okabe

Hirotaka Inoue

Takeshi Omura

Hiroi Yamaguchi

Kazuhiro Hanazawa

Takashi Terashima

Masanori Uesaka

Takumi Umada

Masayasu Nagoshi

Toshito Takamiya

Ryuichi Suehiro

Makoto Watanabe

Yasushi Kitani

Junichi Yotsuji

Tomohiko Ito

Yoshihisa Ichihara

Tomohiro Matsushima

Yasunari Koga

Takeshi Imamura

Takashi Kawano

Michiro Komatsubara

Yasuyuki Hayakawa

Kunihiro Senda

Tomoyuki Okubo

Minoru Takashima

Hiroaki Toda

Takako Yamashita

Koichiro Fujita

Taro Kizu

Eiko Yasuhara

Nobuko Nakagawa

Yukio Usui

A method for forming grooves on a surface of a metal strip, having applying a coating agent for etching resist coating formation to a roller; then, irradiating a laser on the roller while scanning the laser in an axial direction of the roller or in a direction inclined to the axial direction to remove a portion of the coating agent for etching resist coating formation irradiated by the laser; then, bringing the roller into contact with at least one side of the metal strip to transfer the coating agent for etching resist coating formation to the at least one side of the metal strip, with an unapplied area corresponding to the removed portion of the coating agent for etching resist coating formation.

Method for forming grooves on metal strip surface and method for manufacturing grain-oriented electrical steel sheet

A linear groove formation method including forming a coated resist on a surface of a steel sheet, irradiating two or more laser beams onto the surface of the steel sheet while scanning the laser beams in a direction intersecting the rolling direction of the steel sheet cyclically in a rolling direction of the steel sheet, and forming linear grooves by etching portions of the steel sheet. In the laser irradiating process, the coated resist is removed continuously in a sheet transverse direction of the steel sheet by using the laser beams irradiated from respective ones of two or more laser irradiation devices arranged in the sheet transverse direction, and the laser beams are irradiated by shifting centers of two of the laser beams irradiated from two of the laser two of the laser irradiation devices adjacent to each other in the sheet transverse direction.

Linear groove formation method and method for producing grain-oriented electrical steel sheet

The linear groove formation method includes a resist forming process of forming a coated resist on a surface of a steel sheet, a laser irradiating process of irradiating laser beams onto the steel sheet while repeating a laser scanning in a direction intersecting a rolling direction of the steel sheet cyclically in the rolling direction of the steel sheet to remove the coated resist in portions irradiated with the laser beams, and an etching process of forming linear grooves by etching portions of the steel sheet from which the coated resist is removed. In the laser irradiating process, the coated resist is removed by using two or more laser irradiating devices, with a certain irradiation energy, a certain beam diameter in a direction perpendicular to a laser scanning direction, and a certain incidence angle with respect to the surface of the steel sheet.

Linear groove formation method and linear groove forming apparatus, and method for manufacturing grain-oriented electrical steel sheet

A grain-oriented electromagnetic steel sheet exhibits excellent magnetic characteristics and excellent coating film adhesion after strain relieving annealing. The grain-oriented electromagnetic steel sheet includes: a steel sheet; a coating film layer A that is a ceramic coating film which is formed on the steel sheet and has an oxide content of less than 30% by mass; and a coating film layer B that is an insulating tension coating film which is arranged on the coating film layer A and contains an oxide. The binding energy of the 1s orbital of oxygen in the coating film layer B is higher than 530 eV; and tension applied to the steel sheet by the coating film layer B per a thickness of 1.0 &#x3bc;m of the coating film layer B is 4.0 MPa/&#x3bc;m or more.

Grain-oriented electromagnetic steel sheet and method of producing grain-oriented electromagnetic steel sheet

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&#xb0; 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&#xb0; C. at the time of entering the pressure reduced area.

Method of producing grain-oriented electrical steel sheet and production line therefor

Disclosed is a grain-oriented electrical steel sheet including: closure domains, each containing a discontinuous region at a part thereof and extending at an angle within 30&#xb0; with respect to a transverse direction of the steel sheet, wherein a closure domain overlapping portion in the discontinuous region on one surface of the steel sheet has a length &#x3b1; in the transverse direction that is longer than a length &#x3b2; in the transverse direction of the closure domain overlapping portion on the other surface of the steel sheet, and the length &#x3b1; satisfies 0.5&#x2264;&#x3b1;&#x2264;5.0 and the length &#x3b2; satisfies 0.2&#x3b1;&#x2264;&#x3b2;&#x2264;0.8&#x3b1;. Consequently, the iron loss and the deterioration of magnetostrictive properties are suppressed in discontinuous regions, which would be inevitably formed when magnetic domain refining treatment is performed using a plurality of irradiation devices.

Grain-oriented electrical steel sheet and production method therefor

This device scans a high-energy beam in a direction traversing a feed path of a grain-oriented electrical steel sheet having subjected to final annealing so as to irradiate a surface of the steel sheet being passed through with the high-energy beam to thereby perform magnetic domain refinement, the device including an irradiation mechanism for scanning the high-energy beam in a direction orthogonal to the feed direction of the steel sheet, in which the irradiation mechanism has a function of having the scanning direction of the high-energy beam oriented diagonally, relative to the orthogonal direction, toward the feed direction at an angle determined based on a sheet passing speed of the steel sheet on the feed path.

Device to improve iron loss properties of grain-oriented electrical steel sheet

Provided are: a grain-oriented electromagnetic steel sheet exhibiting excellent coating film adhesion and excellent magnetic characteristics; and a method for producing this grain-oriented electromagnetic steel sheet. This grain-oriented electromagnetic steel sheet is provided with a ceramic coating film arranged on a steel sheet, and an oxide insulating tension coating film arranged on the ceramic coating film. The ceramic coating film contains a nitride and an oxide; the nitride contains at least one element selected from the group consisting of Cr, Ti, Zr, Mo, Nb, Si, Al, Ta, Hf, W and Y; and the oxide has a corundum crystal structure. The Young's modulus of the ceramic coating film as determined by a nanoindentation method is 230 GPa or more; the average film thickness of the ceramic coating film is from 0.01 &#x3bc;m to 0.30 &#x3bc;m (inclusive); and the tension of the oxide insulating tension coating film is 10 MPa or more.

Grain-oriented electromagnetic steel sheet and method for producing grain-oriented electromagnetic steel sheet

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 &#x3bc;m or more and a length w along the rolling direction of 250 &#x3bc;m or less.

Grain-oriented electrical steel sheet and process for producing same

Provided are: a grain-oriented electrical steel sheet that has an excellent magnetic property and coating adhesiveness after stress relief annealing; and a production method therefor. This grain-oriented electrical steel sheet has: a steel sheet; a metal coating which contains a metal element and which is disposed on the steel sheet; a coating layer A which is a ceramic coating having an oxide content of less than 30 mass % and which is disposed on the metal coating; and a coating layer B which is an insulating tensile coating containing an oxide and which is disposed on the coating layer A, wherein the metal coating has a thickness of 1.0-10.0 nm, and in the metal element, the atomic radius ratio represented by formula (1) is at least 10%, when the atomic radius of iron is defined as RFe and the atomic radius of the metal element as RA.(|)&#xd7;100.&#x2003;&#x2003;Formula (1):

Grain-oriented electrical steel sheet and production method for grain-oriented electrical steel sheet

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 &#x3bc;m. The thickness of the insulating tensile coating is at least 1.0 &#x3bc;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 %.

Oriented electromagnetic steel sheet and method for manufacturing oriented electromagnetic steel sheet

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 &#x3bc;m to 10 &#x3bc;m, and a power of the laser is 1500 W or more.

Linear groove formation method and linear groove formation device

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.

Grain-oriented electrical steel sheet and method for manufacturing the same

In a grain-oriented electrical steel sheet including: a steel substrate; a forsterite base film; and an insulating coating, critical damage shear stress &#x3c4; between the forsterite base film and the steel substrate is 50 MPa or more and 200 MPa or less. 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.

Grain-oriented electrical steel sheet and method for manufacturing same

Provided are: a grain-oriented electrical steel sheet that has excellent coating adhesiveness and an excellent magnetic property after stress relief annealing; and a production method for therefor. The grain-oriented electrical steel sheet has: a steel sheet; a coating layer A which is a ceramic coating having an oxide content of less than 30 mass % and which is disposed on the steel sheet; and a coating layer B which is an insulating tensile coating containing an oxide and which is disposed on the coating layer A. When a Gaussian fitting is performed on aP-NMR spectrum of the coating layer B within the range of 0 to &#x2212;60 ppm, the proportion of a peak area of &#x2212;17 to &#x2212;33 ppm to the total peak area is 30% or more.

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Tokyo, Japan

Shigehiro Takajo