Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Shohji Nagano

Shinsuke Takatani

Shunsuke Okumura

Yoshiyuki Ushigami

Yoshihiro Arita

Masaru Takahashi

Shuichi Nakamura

Koji Hirano

Yoshio Nakamura

Tatsuhiko Sakai

Shuichi Yamazaki

Kenichi Murakami

Masato Yasuda

Takashi Kataoka

Kazumi Mizukami

Kazuyuki Tashiro

Seiichiro Cho

A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PHO/PHis controlled, an annealing separator applying process where a mass ratio of MgO and AlOin an annealing separator is controlled, a final annealing process where an oxidation degree is controlled when atmosphere includes hydrogen or a dew point is controlled when atmosphere consists of inert gas, and an insulation coating forming process where a baking temperature and a heat treatment temperature are controlled.

Method for producing grain oriented electrical steel sheet

A method of manufacturing a grain-oriented electrical steel sheet according to the present invention includes a process of executing hot rolling on a slab to obtain a hot-rolled sheet; a process of executing hot-rolled sheet annealing on the hot-rolled sheet to obtain an annealed hot-rolled sheet; a process of executing cold rolling on the annealed hot-rolled sheet to obtain a cold-rolled sheet; a process of executing decarburization annealing on the cold-rolled sheet to obtain a decarburization annealed sheet; a process of applying an annealing separator containing alumina as a main component to the decarburization annealed sheet; and a process of executing final annealing on the decarburization annealed sheet to which the annealing separator is applied, wherein the annealing separator contains 28% to 50% by mass of MgO, and wherein an application amount of the annealing separator is 6.0 to 14.0 g/mper one surface of the decarburization annealed sheet.

Method of manufacturing grain-oriented electrical steel sheet

An grain-oriented electrical steel sheet according to the present invention includes: a base steel sheet; an oxide layer that is formed on the base steel sheet and is formed of amorphous SiO; and a tension-insulation coating that is formed on the oxide layer. The base steel sheet includes, as a chemical composition, by mass %, C: 0.085% or less, Si: 0.80% to 7.00%, Mn: 1.00% or less, acid-soluble Al: 0.065% or less, Seq represented by S+0.406·Se: 0.050% or less, and a remainder consisting of Fe and unavoidable impurities. FWHM that is a half width of a peak of cristobalite type aluminum phosphate obtained by X-ray diffraction satisfies (i) when X-ray diffraction is performed using a Co-Kα excitation source, a half width (FWHM-Co) of a peak appearing at 2θ=24.8° is 2.5 degree or less, or (ii) when X-ray diffraction is performed using a Cu-Kα excitation source, a half width (FWHM-Cu) of a peak appearing at 2θ=21.3° is 2.1 degree or less.

Grain-oriented electrical steel sheet

A grain-oriented electrical steel sheet of the present invention has a base steel sheet, an amorphous oxide layer formed on the base steel sheet, and a tension-insulation coating formed on the amorphous oxide layer, in which the base steel sheet contains, as a chemical composition, by mass %, C: 0.085% or less, Si: 0.80 to 7.00%, Mn: 1.50% or less, acid-soluble Al: 0.065% or less, S: 0.013% or less, Cu: 0 to 0.80%, N: 0 to 0.012%, P: 0 to 0.50%, Ni: 0 to 1.00%, Sn: 0 to 0.30%, and Sb: 0 to 0.30%, a remainder is Fe and an impurity, a surface glossiness Gs20(A) in a direction parallel to a rolling direction is 2.0 to 70, and a surface glossiness Gs20(B) in a direction perpendicular to the rolling direction is 2.0 to 70.

This grain-oriented electrical steel sheet does not have a forsterite film present between a base steel sheet and a tension-insulation coating, in which the base steel sheet contains a predetermined element in a predetermined amount, and in a case in which a cross section perpendicular to a rolling direction of the base steel sheet is viewed, when a region having a length of 10 μm from a surface of the base steel sheet toward the inside of the base steel sheet in a sheet thickness direction of the base steel sheet and a length of 20 mm in a direction perpendicular to the sheet thickness direction is an observation region, needle-like inclusions having a length of 1 μm or more are not present in the observation region.

Provided is a grain-oriented electrical steel sheet including a base steel sheet, an intermediate layer which is disposed in contact with the base steel sheet and mainly includes silicon oxide, and an insulation coating which is disposed in contact with the intermediate layer and mainly includes phosphate and colloidal silica, in which the base steel sheet contains predetermined chemical composition, BN having an average particle size of 50 to 300 nm is present, when an emission intensity of B is measured using glow discharge emission analysis, predetermined conditions are satisfied, and a ratio of a major axis to a minor axis of BN is 1.5 or less.

Grain-oriented electrical steel sheet having excellent insulation coating adhesion without forsterite coating

A grain-oriented electrical steel sheet includes a steel sheet and an amorphous oxide layer that is formed on the steel sheet, in which the steel sheet includes, as a chemical composition, by mass %, C: 0.085% or less, Si: 0.80% to 7.00%, Mn: 1.50% or less, acid-soluble Al: 0.065% or less, S: 0.013% or less, Cu: 0% to 0.80%, N: 0% to 0.012%, P: 0% to 0.50%, Ni: 0% to 1.00%, Sn: 0% to 0.30%, Sb: 0% to 0.30%, and a remainder of Fe and impurities, and a NSIC value of a surface is 4.0% or more, the NSIC value being obtained by measuring an image clearness of the surface using an image clearness measuring device.

A grain-oriented electrical steel sheet includes: a steel sheet; an oxide layer including SiOthat is formed on the steel sheet; and a tension-insulation coating that is formed on the oxide layer, in which the steel sheet includes, as a chemical composition, by mass %, C: 0.085% or less, Si: 0.80% to 7.00%, Mn: 1.00% or less, acid-soluble Al: 0.065% or less, S: 0.013% or less, Cu: 0% to 0.80%, N: 0% to 0.012%, P: 0% to 0.50%, Ni: 0% to 1.00%, Sn: 0% to 0.30%, Sb: 0% to 0.30%, and a remainder of Fe and impurities, the tension-insulation coating includes a chromium compound, and the Fe content in the oxide layer and the tension-insulation coating is 70 mg/mto 250 mg/m.

A method of manufacturing a grain-oriented electrical steel sheet, includes: a laser processing process of forming a laser processed portion by irradiating a region on one end side of a steel sheet in a width direction after being subjected to a cold rolling process with a laser beam along a rolling direction of the steel sheet; and a finish annealing process of coiling the steel sheet with the laser processed portion formed thereon in a coil shape and performing a finish annealing on the coil-shaped steel sheet. In the laser processing process, a melted-resolidified portion having a depth of greater than% and equal to or less than% of a sheet thickness of the steel sheet is formed by the irradiation of the laser beam at a position corresponding to the laser processed portion.

Grain-oriented electrical steel sheet and method of manufacturing grain-oriented electrical steel sheet

To provide a grain oriented electrical steel sheet that can securely suppress propagation of lateral strain, and can make a product even from a portion where the lateral strain occurs. A grain oriented electrical steel sheet of the present invention has a linearly altered portiongenerated in a glass coating filmat one of side edges of a steel sheet, in a continuous line or in a discontinuous broken line in a direction parallel with a rolling direction of the steel sheet, and having a composition different from a composition in other portions of the glass coating film. An average value of a deviation angle of a direction of an axis of easy magnetization of crystal grains relative to the rolling direction is 0&#xb0; or more and 20&#xb0; or less in a base metal iron portion of the steel sheetat a position along a width direction of the steel sheet, the position corresponding to the linearly altered portion

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Tokyo, Japan

Shohji Nagano