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：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.

公开(公告)号：US20210317542A1

公开(公告)日：2021-10-14

申请号：US17256891

申请日：2018-07-13

Applicant: NIPPON STEEL CORPORATION

Inventor： Shuichi NAKAMURA ,  Seiki TAKEBAYASHI ,  Yoshiyuki USHIGAMI ,  Shinsuke TAKATANI ,  Hiroyasu FUJII

IPC: C21D9/46 ,  C23C8/02 ,  C21D8/12 ,  C23C8/18 ,  C22C38/02 ,  C22C38/00

Abstract: In a base sheet for a grain-oriented electrical steel sheet of the present invention, an amount of surface oxygen x per one surface of the base sheet and a value y of a peak (ΔR/R0 @1250 cm−1) of SiO2 on the surface of the base sheet obtained by infrared reflection spectroscopy satisfy y≥1500x2.5 and y≥0.24. A method of manufacturing the base sheet for a grain-oriented electrical steel sheet of the present invention includes: adjusting the amount of surface oxygen per one surface of a final-annealed grain-oriented silicon steel sheet to more than 0.01 g/m2 and 0.05 g/m2 or less, or more than 0.05 g/m2 and 0.10 g/m2 or less; and performing thermal oxidation annealing in an atmosphere in which an oxidation potential represented by a ratio PH2O/PH2 of water vapor pressure to hydrogen pressure is 0.0081 or less in a case where the amount of surface oxygen is more than 0.01 g/m2 and 0.05 g/m2 or less, or in an atmosphere in which the oxidation potential is 0.005 or less in a case where the amount of surface oxygen is more than 0.05 g/m2 and 0.10 g/m2 or less, at a soaking temperature of 1000° C. or lower to form an externally oxidized layer on a surface of the grain-oriented silicon steel sheet.

公开(公告)号：US20210246524A1

公开(公告)日：2021-08-12

申请号：US17263846

申请日：2019-07-31

Applicant: NIPPON STEEL CORPORATION

Inventor： Shuichi NAKAMURA ,  Yusuke KAWAMURA ,  Shingo OKADA ,  Tomoaki ITO ,  Shinya YANO

IPC: C21D8/12 ,  H01F1/147 ,  C21D9/46 ,  C22C38/02 ,  C22C38/00 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50

Abstract: A grain oriented electrical steel sheet includes the texture aligned with Goss orientation. In the grain oriented electrical steel sheet, when (α1 β1 γ1) and (α2 β2 γ2) represent deviation angles of crystal orientations measured at two measurement points which are adjacent on the sheet surface and which have an interval of 1 mm, the boundary condition BA is defined as |β2−β1|≥0.5°, and the boundary condition BB is defined as [(α2−α1)2+(β2−β1)2+(γ2−γ1)2]1/2≥2.0°, the boundary which satisfies the boundary condition BA and which does not satisfy the boundary condition BB is included.

公开(公告)号：US20230084111A1

公开(公告)日：2023-03-16

申请号：US17796217

申请日：2020-02-05

Applicant: NIPPON STEEL CORPORATION

Inventor： Shuichi NAKAMURA ,  Yusuke KAWAMURA

IPC: C22C38/02 ,  C22C38/12 ,  C22C38/60 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00

Abstract: A grain oriented electrical steel sheet includes the texture aligned with Goss orientation. In the grain oriented electrical steel sheet, when a grain size RAαC, a grain size RAβC, and a grain size RAγC are defined in a transverse direction C, the grain sizes satisfy RAγC

公开(公告)号：US20230071853A1

公开(公告)日：2023-03-09

申请号：US17797072

申请日：2020-02-05

Applicant: NIPPON STEEL CORPORATION

Inventor： Shuichi NAKAMURA ,  Yusuke KAWAMURA

IPC: H01F1/147 ,  C22C38/50 ,  C22C38/48 ,  C22C38/42 ,  C22C38/06 ,  C22C38/04 ,  C22C38/34 ,  C22C38/00 ,  C21D9/46 ,  C21D8/12 ,  C21D8/00 ,  C21D6/00

Abstract: A grain oriented electrical steel sheet includes the texture aligned with Goss orientation. In the grain oriented electrical steel sheet, when a grain size RAαL, a grain size RAβL, and a grain size RAγL are defined in a rolling direction L, the grain sizes satisfy RAβL

公开(公告)号：US20220098694A1

公开(公告)日：2022-03-31

申请号：US17422695

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Yoshiyuki USHIGAMI ,  Shuichi NAKAMURA ,  Hiroyasu FUJII ,  Norikazu FUJII

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

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 of a final sheet thickness by subjecting the hot rolled sheet to a single cold rolling process or multiple cold rolling processes having intermediate annealing performed between the cold rolling processes; a decarburization annealing process of subjecting the steel sheet to decarburization annealing; and a final annealing process of applying an annealing separator containing alumina as a main component to the steel sheet and subjecting the steel sheet to final annealing. The silicon steel material contains: in terms of mass %, Si: 0.8 to 7.0%; C: 0.085% or less; acid-soluble Al: 0.010 to 0.065%; N: 0.004 to 0.012%; Mn: 1.00% or less; S: 0.050% or less; a total of 0.01 to 0.20% of one or both of Sn and Sb; and the remainder: Fe and impurities.

公开(公告)号：US20210272728A1

公开(公告)日：2021-09-02

申请号：US17259119

申请日：2018-07-13

Applicant: NIPPON STEEL CORPORATION

Inventor： Takashi KATAOKA ,  Yoshiyuki USHIGAMI ,  Shuichi NAKAMURA ,  Hiroyasu FUJII ,  Yoichi ZAIZEN

IPC: H01F1/147 ,  C21D9/46 ,  C21D8/12 ,  C21D6/00 ,  C22C38/34 ,  C22C38/20 ,  C22C38/32 ,  C22C38/04 ,  C22C38/00 ,  C22C38/06 ,  C23C8/14

Abstract: A grain oriented electrical steel sheet includes: by mass %, 0.010% or less of C; 2.50 to 4.00% of Si; 0.0010 to 0.0100% of acid soluble Al; 0.012% or less of N; 1.00% or less of Mn; 0.02% 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, a time differential curve fM(t) of a glow discharge optical emission spectrum of a metallic element M (Al) in the SiO2 intermediate oxide film layer satisfies a predetermined condition.

公开(公告)号：US20230386727A1

公开(公告)日：2023-11-30

申请号：US18033398

申请日：2021-10-26

Applicant: NIPPON STEEL CORPORATION

Inventor： Shuichi NAKAMURA

IPC: H01F27/245 ,  H01F1/16

CPC classification number: H01F27/2455 ,  H01F1/16

Abstract: This wound core is a wound core including a substantially rectangular wound core main body in a side view, wherein, in the wound core main body, first planar portions and corner portions are alternately continuous in a longitudinal direction, each corner portion has a curved shape in a side view of the grain-oriented electrical steel sheet, two or more bent portions having a second planar portion between the adjacent bent portions are provided, and in at least one of the first planar portion and second planar portion in the vicinity of the bent portion, the following Formula (1) is satisfied:


(Nac+Nal)/Nt≥0.010  (1)



here, Nt is a total number of grain boundary determination locations in the first planar portion and second planar portion region adjacent to the bent portion, and Nac and Nal each are a number of determination location at which subgrain boundaries are able to be identified in a direction parallel to and direction perpendicular to the bent portion boundary.

公开(公告)号：US20220112573A1

公开(公告)日：2022-04-14

申请号：US17421975

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

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

IPC: C21D9/46 ,  C22C38/34 ,  C22C38/32 ,  C22C38/24 ,  C22C38/16 ,  C22C38/14 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00 ,  C21D8/12 ,  C21D8/00 ,  C21D6/00 ,  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 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.