公开(公告)号：US20220081746A1

公开(公告)日：2022-03-17

申请号：US17421771

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinsuke TAKATANI ,  Yoshiyuki USHIGAMI

IPC: C22C38/54 ,  C22C38/00 ,  C22C38/42 ,  C22C38/44 ,  C22C38/48 ,  C22C38/46 ,  C22C38/50 ,  C21D9/46 ,  C21D8/02

Abstract: A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PH2O/PH2 is controlled and pickling is conducted after decreasing temperature, an annealing separator applying process where a mass ratio of MgO and Al2O3 in 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, an annealing separator removing process where water-washing is conducted using solution with inhibitor, and an insulation coating forming process where a mass ratio of phosphoric acid and metal compound in insulation coating forming solution is controlled.

公开(公告)号：US20220081744A1

公开(公告)日：2022-03-17

申请号：US17422219

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Masato YASUDA ,  Yoshihiro ARITA ,  Masaru TAKAHASHI ,  Yoshiyuki USHIGAMI ,  Shohji NAGANO

IPC: C22C38/06 ,  C22C38/02 ,  C22C38/04 ,  C22C38/00 ,  C21D8/02

Abstract: 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.

公开(公告)号：US20220068526A1

公开(公告)日：2022-03-03

申请号：US17423013

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Yoshiyuki USHIGAMI ,  Masato MIZOKAMI ,  Shingo OKADA ,  Yoichi ZAIZEN ,  Shinji YAMAMOTO

IPC: H01F1/147 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D9/46 ,  C21D8/12 ,  C21D8/00 ,  C21D6/00 ,  C21D3/04

Abstract: 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 μm 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-AMPC100, ave-AMPC100 is 0.0001 to 0.050 μm.

公开(公告)号：US20210123115A1

公开(公告)日：2021-04-29

申请号：US17258968

申请日：2018-07-13

Applicant: NIPPON STEEL CORPORATION

Inventor： Takashi KATAOKA ,  Yoshiyuki USHIGAMI ,  Shuichi NAKAMURA ,  Hiroyasu FUJII ,  Shunsuke OKUMURA

IPC: C21D9/46 ,  C21D6/00 ,  C21D8/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C22C38/18 ,  C22C38/16 ,  H01F1/14

Abstract: A grain oriented electrical steel sheet includes: by mass %, 0.010% or less of C; 2.50 to 4.00% of Si; 0.010% or less of acid soluble Al; 0.012% or less of N; 1.00% or less of Mn; 0.020% or less of S; and a balance consisting of Fe and impurities, and has a tension-insulation coating at steel sheet surface and a SiO2 intermediate oxide film layer with an average thickness of 1.0 nm to 1.0 μm at an interface between the tension-insulation coating and the steel sheet surface. In the grain oriented electrical steel, when a surface of the intermediate oxide film layer is analyzed by an infrared reflection spectroscopy, a peak intensity IA at 1250 cm−1 and a peak intensity IB at 1200 cm−1 satisfy IB/IA≥0.010.

公开(公告)号：US20240186042A1

公开(公告)日：2024-06-06

申请号：US18285440

申请日：2022-05-27

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinsuke TAKATANI ,  Kazutoshi TAKEDA ,  Masaru TAKAHASHI ,  Yoshiyuki USHIGAMI

IPC: H01F1/18 ,  C21D1/74 ,  C21D6/00 ,  C21D8/02 ,  C21D8/12 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/60 ,  C23C22/82 ,  C23C28/04

CPC classification number: H01F1/18 ,  C21D1/74 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0284 ,  C21D8/1222 ,  C21D8/1233 ,  C21D8/1255 ,  C21D8/1261 ,  C21D8/1266 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/60 ,  C23C22/82 ,  C23C28/04

Abstract: Provided is a grain oriented electrical steel sheet including a base metal steel sheet, an intermediate layer and an insulation coating, wherein: the intermediate layer is an oxide film; an average thickness of the oxide film is 2-500 nm; the insulation coating is a phosphate coating; an average thickness of the insulation coating is 0.1-10 μm. When grazing incidence X-ray diffraction is performed on the phosphate coating using a Co-Kα excitation source, the X-ray diffraction pattern has a diffraction peak originating from cristobalite-type aluminum phosphate at a diffraction angle of 2θ=24.8°; a half value width FWHM0.5 of the diffraction peak under a diffraction condition with an X-ray incident angle ω=0.5° and a half value width FWHM1.0 of the diffraction peak under a diffraction condition with an X-ray incident angle ω=1.0° satisfy 0.20°≤FWHM0.5≤2.00°, 0.20°≤FWHM1.0≤2.00°, and 0°≤|F.WHM0.5−FWHM1.0|≤1.00°.

公开(公告)号：US20220119958A1

公开(公告)日：2022-04-21

申请号：US17422401

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroyasu FUJII ,  Seiki TAKEBAYASHI ,  Yoshiyuki USHIGAMI ,  Takashi KATAOKA ,  Shunsuke OKUMURA

IPC: C23C22/78 ,  C21D9/46 ,  C21D3/04 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06

Abstract: This grain-oriented electrical steel sheet includes a steel sheet, an insulation coating disposed on the steel sheet, and a spinel present at a part on the steel sheet at an interface between the steel sheet and the insulation coating by being fitted into the insulation coating, in which an amount of the spinel is 5 to 50 mg/m2 per unit area of a surface of the steel sheet.

公开(公告)号：US20220119905A1

公开(公告)日：2022-04-21

申请号：US17421938

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinsuke TAKATANI ,  Yoshiyuki USHIGAMI ,  Shuichi NAKAMURA ,  Shohji NAGANO ,  Shunsuke OKUMURA

IPC: C21D9/46 ,  C21D8/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/48 ,  C22C38/50 ,  C22C38/60 ,  C23G1/02 ,  C23C28/04

Abstract: A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PH2O/PH2 is controlled, an annealing separator applying process where a mass ratio of MgO and Al2O3 in 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.

公开(公告)号：US20220098690A1

公开(公告)日：2022-03-31

申请号：US17421820

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinsuke TAKATANI ,  Yoshiyuki USHIGAMI

IPC: C21D9/46 ,  C21D8/12 ,  C21D6/00 ,  C22C38/54 ,  C22C38/60 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/04 ,  C22C38/02 ,  C22C38/06 ,  C22C38/00 ,  C21D3/04 ,  H01F1/147

Abstract: A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PH2O/PH2 is controlled, an annealing separator applying process where a mass ratio of MgO and MCl in 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 mass ratio of phosphoric acid and metal compound in insulation coating forming solution is controlled.

公开(公告)号：US20210388459A1

公开(公告)日：2021-12-16

申请号：US17422618

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Yoshiyuki USHIGAMI ,  Shuichi NAKAMURA ,  Hiroyasu FUJII

IPC: C21D9/46 ,  C22C38/34 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/20 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00 ,  C21D8/12 ,  C21D8/00 ,  C21D6/00 ,  C21D3/04 ,  C23C8/26 ,  C23C8/02 ,  C23C8/80 ,  H01F1/147

Abstract: A method for manufacturing a grain-oriented electrical steel sheet includes: a silicon steel material production process of producing a silicon steel material; a hot rolling process of obtaining a hot rolled sheet by subjecting the silicon steel material to hot rolling; a cold rolling process of obtaining a steel sheet having a final sheet thickness by subjecting the hot rolled sheet to a single cold rolling process or to multiple cold rolling processes having intermediate annealing performed between cold rolling processes; a decarburization annealing process of subjecting the steel sheet to decarburization annealing using a decarburization annealing furnace including a heating area and a soaking area; and a final annealing process of applying an annealing separator having alumina as a main component to the steel sheet and subjecting the steel sheet to final annealing, wherein, in the decarburization annealing process, when X represents the Cr content of the silicon steel material in terms of mass %, an oxidation degree P1 of an atmosphere gas in the heating area satisfies the following Expression 1 and an oxidation degree P2 of an atmosphere gas in the soaking area satisfies the following Expression 2: 0.18X−0.008≤P1≤0.25X+0.15≤0.20  (Expression 1); and 0.01≤P2≤0.15  (Expression 2).

公开(公告)号：US20220102035A1

公开(公告)日：2022-03-31

申请号：US17422011

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Shuichi NAKAMURA ,  Yoshiyuki USHIGAMI ,  Hiroyasu FUJII

IPC: H01F1/147 ,  C21D9/46 ,  C23C22/78 ,  C21D8/12 ,  C21D6/00

Abstract: A grain-oriented electrical steel sheet according to an aspect of the present invention includes an underlying steel sheet and a tension-insulation coating arranged on the surface of the underlying steel sheet, and a ten-point average roughness RzL in an L direction obtained when the tension-insulation coating is removed from the grain-oriented electrical steel sheet with an alkaline solution, and then the surface of the underlying steel sheet is measured in a rolling direction is 6.0 μm or less.