Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Nippon Steel Corooration

Hideyuki Hamamura

Tatsuhiko Sakai

Satoshi Arai

Hirofumi Imai

Fumiaki Takahashi

Shunsuke Okumura

Hisashi Mogi

Takashi Kataoka

Koji Hirano

Shinji Yamamoto

Yoshiyuki Ushigami

Naoya Hamada

Kazutoshi Takeda

Kenichi Murakami

Masato Mizokami

Hideyuki Kobayashi

Masaru Takahashi

Hiroyasu Fujii

Shinsuke Takatani

Norikazu Fujii

Nobusato Morishige

Yasuhiro Mayumi

Atsushi Sugihashi

Kazuhiko Fukutani

Takahito Mizumura

Shinya Hayashi

Tomohito Tanaka

Hirotoshi Tada

Toshiya Takechi

Tomoya Suenaga

Motoi Kido

Haruhiko Atsumi

Satoshi Yamaguchi

Keiji Iwata

Masao Yabumoto

Kimihiko Sugiyama

Masamitsu Kubota

Naoto Masumitsu

Takeo Aramaki

Masataka Iwaki

Kaoru Sato

Ushigami Yoshiyuki

This grain-oriented electrical steel sheet includes a base steel sheet having a predetermined chemical composition, a glass coating formed on the base steel sheet, and a tension-applied insulation coating formed on the glass coating, on a front surface of the base steel sheet, a plurality of linear strains that extend continuously or intermittently in a direction intersecting with a rolling direction are present, intervals p in the rolling direction of the plurality of linear strains adjacent to each other are 3.0 to 9.0 mm, widths of the linear strains are 10 to 250 μm, and, in an X-ray topographic spectrum in a range of 1.50 mm in the rolling direction that is obtained from an X-ray topographic image of the front surface and includes the linear strain at a center, a full width at half maximum of a peak of the X-ray topographic spectrum including a maximum value of a spectral intensity is 0.02 mm or more and 0.10 mm or less.

Grain-oriented electrical steel sheet and method for manufacturing same

A groove processing device that forms a groove in an object's surface using laser beams includes: a light source device that outputs the laser beams; a polygon mirror that reflects the laser beams that are output; a condensing optical system provided on an optical path of the laser beams that are reflected and focuses the laser beams; and a shielding plate provided between the condensing optical system and the object at a position which blocks some of the laser beams and blocks some of the laser beams. Among the laser beams that are focused, some that are not blocked form the groove in the surface of the object at a focus. The shielding plate is provided closer to the condensing optical system than the focus and is rotated with respect to the object's surface to block the laser beams that do not form the groove.

Groove processing device and groove processing method

The method for manufacturing a grain-oriented electrical steel sheet is a method for manufacturing a grain-oriented electrical steel sheet including a strain region forming process of irradiating the grain-oriented electrical steel sheet having a base steel sheet (), an intermediate layer () disposed to be in contact with the base steel sheet (), and an insulation coating () disposed to be in contact with the intermediate layer () with an electron beam and forming a strain region (D) which extends in a direction intersecting a rolling direction of the base steel sheet () on a surface of the base steel sheet (), wherein, in the strain region forming process, a temperature of a central portion of the strain region (D) in the rolling direction of the base steel sheet () and an extension direction of the strain region (D) is heated to 800° C. or higher and 2000° C. or lower.

Method for manufacturing grain-oriented electrical steel sheet

This grain-oriented electrical steel sheet includes a base steel sheet, a forsterite-based primary film disposed on a surface of the base steel sheet, and a phosphate-based tension-imparting film containing no chromium, which is disposed on a surface of the primary film. In a case where a Ti content and a S content are respectively expressed as XTi and XS, by mass %, the forsterite-based primary film satisfies Expression (1) and Expression (2). A strain-introduced magnetic domain control is performed on the grain-oriented electrical steel sheet0.10≤XTi/XS≤10.00  Expression (1)XTi+XS≥0.10 mass %.  Expression (2)

The grain-oriented electrical steel sheet according to the present embodiment is a grain-oriented electrical steel sheet having a base steel sheet (), an intermediate layer () disposed to be in contact with the base steel sheet (), and an insulation coating () disposed to be in contact with the intermediate layer (). The grain-oriented electrical steel sheet according to the present embodiment includes a surface of the base steel sheet () having a strain region (D) which extends in a direction intersecting a rolling direction of the base steel sheet (), and a crystalline phosphorus oxide MPOpresent in the insulation coating () on the strain region (D) in a cross-sectional view of a surface parallel to the rolling direction and a sheet thickness direction of the base steel sheet (). (M means at least one or both of Fe and Cr.)

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

The grain-oriented electrical steel sheet according to the present invention is a grain-oriented electrical steel sheet having a base steel sheet (), an intermediate layer () disposed to be in contact with the base steel sheet (), and an insulation coating () disposed to be in contact with the intermediate layer (), and the grain-oriented electrical steel sheet includes a surface of the base steel sheet () having a groove (G) which extends in a direction intersecting a rolling direction of the base steel sheet (), in which in a cross-sectional view of a plane parallel to the rolling direction and a sheet thickness direction of the base steel sheet (), when a region between end portions of the groove (G) is defined as a groove part (R), an average thickness of the intermediate layer () of the groove part (R) is 0.5 times or more and 3.0 times or less an average thickness of the intermediate layer () other than the groove part (R), and an area ratio of voids in the insulation coating () of the groove part (R) is 15% or less.

A grain-oriented electrical steel sheet according to the present invention includes a base steel sheet having plural grooves on a surface and a glass film formed on the surface of the base steel sheet. In case of viewing region including grooves in cross section orthogonal to groove longitudinal direction, a straight line passing through peak point present on profile line of glass film and parallel to groove width direction orthogonal to sheet thickness direction in cross section is defined as reference line, a point present on boundary line between glass film and base steel sheet and present at lowest location in sheet thickness direction is defined as deepest point, and a point present on boundary line and present at the highest location in the sheet thickness direction in region having the deepest point in a center and having length of 2 &#x3bc;m in groove width direction is defined as shallowest point, a relationship between shortest distance A between reference line and deepest point and shortest distance B between reference line and shallowest point satisfies Expression (1).0.1 &#x3bc;m&#x2264;&#x2264;5.0 &#x3bc;m&#x2003;&#x2003;(1)

Grain-oriented electrical steel sheet and manufacturing method thereof

A method for manufacturing a grain-oriented electrical steel sheet according to an aspect of the present invention includes a step of obtaining a hot-rolled steel sheet by carrying out hot rolling on a slab containing a predetermined component composition with a remainder including Fe and impurities, a step of obtaining a hot-rolled annealed sheet by carrying out hot-rolled sheet annealing as necessary, a step of carrying out pickling to obtain a pickled sheet, a step of carrying out cold rolling to obtain a cold-rolled steel sheet, a step of carrying out primary recrystallization annealing, a step of applying an annealing separating agent including MgO to a surface and then carrying out final annealing to obtain a final-annealed sheet, and a step of applying an insulating coating and then carrying out flattening annealing.

Method for manufacturing grain-oriented electrical steel sheet and grain-oriented electrical steel sheet

A grain-oriented electrical steel sheet according to the present invention has a steel sheet surface provided with grooves and includes two or more broken lines including the grooves having a length of 5 to 10 mm on a straight line intersecting a rolling direction on the steel sheet surface. In each of the broken lines including the grooves, the grooves are arranged at equal intervals, and a ratio of the length of the groove to a length of a non-groove is in a range of 1:1 to 1.5:1.

Grain-oriented electrical steel sheet

A grain-oriented electrical steel sheet according to the present invention has a steel sheet surface provided with grooves. An average protrusion height of the surface protrusion extending along a longitudinal direction of the groove is more than 5 &#x3bc;m and not more than 10 &#x3bc;m. When the surface protrusion is viewed in a cross section including the longitudinal direction of the groove and a normal direction of the steel sheet surface, the surface protrusion includes specific portions each having a height of 50% or more with respect to a height of each peak point appearing on a profile line of the surface protrusion. In the longitudinal direction of the groove, the total length of the specific portions is a length of 30% or more with respect to an overall length of the surface protrusion.

In a laser processing apparatus for refining magnetic domains of a grain-oriented electromagnetic steel sheet by setting a laser beam to be focused on the grain-oriented electromagnetic steel sheet and scanned in a scanning direction, the laser beam focused on the grain-oriented electromagnetic steel sheet is linearly polarized light, and an angle between a linear polarization direction and the scanning direction is higher than 45&#xb0; and equal to or lower than 90&#xb0;.

Laser processing apparatus

A grain-oriented electrical steel sheet according to the present embodiment is a grain-oriented electrical steel sheet having a groove formed on a surface, in which, in a cross section of the grain-oriented electrical steel sheet orthogonal to the groove, a KAM value is 0.1 or more and 3.0 or less in a region on a central side in a thickness direction of the grain-oriented electrical steel sheet with respect to the groove, the region being surrounded by a square having one side in contact with a groove bottom of the groove and having a length of 50 &#x3bc;m in each side.

Provided is a grain-oriented electrical steel sheet including a steel sheet having a steel sheet surface in which a groove, which extends in a direction intersecting a rolling direction and of which a groove depth direction matches a sheet thickness direction, is formed. In a case where the steel sheet surface is seen from the sheet thickness direction, the steel sheet surface is provided with a groove group that is constituted by a plurality of the grooves arranged in a sheet width direction, the grooves, which constitute the groove group, are arranged in such a manner that adjacent grooves overlap each other on a projection plane perpendicular to the rolling direction, and a plurality of the groove groups are arranged with an interval in the rolling direction.

In a laser processing apparatus for refining magnetic domains of a grain-oriented electromagnetic steel sheet by setting a laser beam to be focused on the grain-oriented electromagnetic steel sheet and scanned in a scanning direction, the laser beam focused on the grain-oriented electromagnetic steel sheet is linearly polarized light, and the angle between the linear polarization direction and the scanning direction is equal to or higher than 0&#xb0; and lower than 45&#xb0;.

Provided is a grain-oriented electrical steel sheet including a steel sheet having a steel sheet surface in which a groove, which extends in a direction intersecting a rolling direction and of which a groove depth direction matches a sheet thickness direction, is formed. An average depth D of the groove is greater than 10 &#x3bc;m and equal to or less than 40 &#x3bc;m in a case where the groove is seen on a groove-width-direction cross-section that is perpendicular to a groove extension direction, when a center of the groove in the groove width direction is defined as a groove width center, a deepest portion of the groove deviates from the groove width center toward one side in the groove width direction, and a cross-sectional shape of the groove is asymmetric with respect to the groove width center as a reference in the groove width direction.

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Futtsu, Japan

Hideyuki Hamamura