公开(公告)号：US20220090227A1

公开(公告)日：2022-03-24

申请号：US17421779

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Yoshiyuki USHIGAMI ,  Shinji YAMAMOTO ,  Hideyuki HAMAMURA ,  Takashi KATAOKA ,  Shunsuke OKUMURA

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

Abstract: The grain-oriented electrical steel sheet according to the present embodiment is a grain-oriented electrical steel sheet having a base steel sheet (1), an intermediate layer (4) disposed to be in contact with the base steel sheet (1), and an insulation coating (3) disposed to be in contact with the intermediate layer (4). The grain-oriented electrical steel sheet according to the present embodiment includes a surface of the base steel sheet (1) having a strain region (D) which extends in a direction intersecting a rolling direction of the base steel sheet (1), and a crystalline phosphorus oxide M2P4O13 present in the insulation coating (3) 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 (1). (M means at least one or both of Fe and Cr.)

公开(公告)号：US20220081749A1

公开(公告)日：2022-03-17

申请号：US17422225

申请日：2020-01-16

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinsuke TAKATANI ,  Takashi KATAOKA ,  Yoshiyuki USHIGAMI ,  Kenichi MURAKAMI ,  Hiroyasu FUJII ,  Shingo OKADA ,  Seiki TAKEBAYASHI

IPC: C22C38/60 ,  C21D8/12 ,  C21D9/46 ,  C22C38/34 ,  C22C38/00 ,  C22C38/06 ,  C22C38/20 ,  C23G1/08 ,  C22C38/04

Abstract: This manufacturing method of a grain-oriented electrical steel sheet is a manufacturing method of a grain-oriented electrical steel sheet having no forsterite film, in which in a decarburization annealing process, a cold-rolled steel sheet is (i-1) heated at an average heating rate (HR1) of 40 to 500° C./sec in a temperature range of 550° C. or higher and lower than 720° C., (i-2) heated at an average heating rate (HR2), which is 5 to 50° C./sec, in a temperature range of 720° C. to T1° C. (770° C.≤T1 (° C.)≤900° C.), and (ii) retained at the temperature of T1° C. for 50 to 1000 seconds to make an amount of C 25 ppm or less in an atmosphere of an oxygen partial pressure (P1) which is 0.0010 to 0.20.

公开(公告)号：US20210047704A1

公开(公告)日：2021-02-18

申请号：US16980461

申请日：2019-03-20

Applicant: NIPPON STEEL CORPORATION

Inventor： Nobusato MORISHIGE ,  Takashi KATAOKA ,  Haruhiko ATSUMI ,  Yasuhiro MAYUMI ,  Atsushi SUZUKI ,  Tomoya SUENAGA ,  Teruyuki TAMAKI

IPC: C21D8/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/60 ,  C21D9/46

Abstract: A method for manufacturing a grain-oriented electrical steel sheet including a step of hot-rolling a slab containing a predetermined component composition with a remainder including Fe and an impurity to obtain a hot-rolled steel sheet, a step of, after carrying out hot-rolled steel sheet annealing on the hot-rolled steel sheet, carrying out cold rolling to obtain a cold-rolled steel sheet, a step of carrying out primary recrystallization annealing including a rapid temperature increase at an average temperature increase velocity V of 400° C./s or more and imparting of a steel sheet tensile force S on the cold-rolled steel sheet, and a step of applying an annealing separating agent to a surface of the cold-rolled steel sheet after the primary recrystallization annealing and then carrying out flattening annealing.

公开(公告)号：US20210043345A1

公开(公告)日：2021-02-11

申请号：US16978155

申请日：2019-03-22

Applicant: NIPPON STEEL CORPORATION

Inventor： Takashi KATAOKA ,  Ichiro TANAKA ,  Haruhiko ATSUMI ,  Kazutoshi TAKEDA ,  Hirotoshi TADA

IPC: H01F1/147 ,  C21D9/46 ,  C21D8/12 ,  C21D6/00 ,  C22C38/60 ,  C22C38/20 ,  C22C38/16 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C22C38/34

Abstract: A grain-oriented electrical steel sheet includes: a base steel sheet having a predetermined chemical composition; a glass coating provided on the surface of the base steel sheet; and a tension-applying insulation coating provided on the surface of the glass coating, in which linear thermal strains having, a predetermined angle (r) with respect to a transverse direction which is a direction orthogonal to a rolling direction are periodically formed on the surface of the tension-applying insulation coating at predetermined intervals along the rolling direction, a full width at half maximum Fl on the linear thermal strain and a full width at half maximum F2 at an intermediate position between the two linear thermal strains adjacent to each other satisfy 0.00

公开(公告)号：US20240183012A1

公开(公告)日：2024-06-06

申请号：US18285451

申请日：2022-04-06

Applicant: NIPPON STEEL CORPORATION

Inventor： Kazutoshi TAKEDA ,  Takashi KATAOKA ,  Shinsuke TAKATANI ,  Yuuki KOGAKURA ,  Yuki KUNITA

IPC: C22C38/02 ,  C21D6/00 ,  C21D8/12 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06

CPC classification number: C22C38/02 ,  C21D6/008 ,  C21D8/1272 ,  C21D8/1283 ,  C21D8/1288 ,  C22C38/001 ,  C22C38/004 ,  C22C38/04 ,  C22C38/06 ,  C21D2201/05

Abstract: This grain-oriented electrical steel sheet includes: a base steel sheet; and an insulating coating formed on a surface of the base steel sheet, in which the insulating coating includes an intermediate layer formed on a base steel sheet side and containing a crystalline metal phosphate, and a tension coating layer formed on a surface side of the insulating coating, an average thickness of the intermediate layer is 0.3 to 10.0 μm, an average thickness of the insulating coating is 2.0 to 10.0 μm, the crystalline metal phosphate of the intermediate layer is one or two or more of zinc phosphate, manganese phosphate, iron phosphate, and zinc calcium phosphate, the tension coating layer contains a metal phosphate and silica, and an amount of the silica in the tension coating layer is 20 to 60 mass %.

公开(公告)号：US20240177899A1

公开(公告)日：2024-05-30

申请号：US18283423

申请日：2022-03-28

Applicant: NIPPON STEEL CORPORATION

Inventor： Takashi KATAOKA ,  Tomohito TANAKA ,  Masataka IWAKI ,  Kazutoshi TAKEDA ,  Hideyuki HAMAMURA

IPC: H01F1/147 ,  C21D6/00 ,  C21D8/12 ,  C21D9/46 ,  C21D10/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/16 ,  C22C38/34 ,  C22C38/60 ,  C23D3/00 ,  C23D5/04 ,  C23D13/00

CPC classification number: H01F1/14783 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/1222 ,  C21D8/1233 ,  C21D8/1255 ,  C21D8/1261 ,  C21D8/1266 ,  C21D8/1283 ,  C21D8/1288 ,  C21D9/46 ,  C21D10/005 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/16 ,  C22C38/34 ,  C22C38/60 ,  C23D3/00 ,  C23D5/04 ,  C23D13/00 ,  C21D2201/05 ,  C22C2202/02

Abstract: 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.

公开(公告)号：US20230243013A1

公开(公告)日：2023-08-03

申请号：US18009919

申请日：2021-06-23

Applicant: NIPPON STEEL CORPORATION

Inventor： Nobusato MORISHIGE ,  Kazumi MIZUKAMI ,  Ryutaro YAMAGATA ,  Takashi KATAOKA ,  Haruhiko ATSUMI ,  Daisuke ITABASHI ,  Junichi TAKAOBUSHI

IPC: C21D9/46 ,  C21D8/12 ,  C22C38/60 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  H01F1/147 ,  H01F41/00

CPC classification number: C21D9/46 ,  C21D8/1222 ,  C21D8/1233 ,  C21D8/1272 ,  C21D8/1283 ,  C21D8/1255 ,  C22C38/60 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/002 ,  C22C38/001 ,  C21D8/1261 ,  H01F1/14775 ,  H01F41/00 ,  C21D2201/05 ,  C22C2202/02

Abstract: A new and improved method for producing grain-oriented electrical steel sheet enabling production of grain-oriented electrical steel sheet realizing high magnetic flux density and excellent in magnetic characteristics, that is, as one aspect, a method for producing grain-oriented electrical steel sheet comprising a hot rolling process, cold rolling process, primary recrystallization annealing process, finish annealing process, and flattening annealing process, wherein shot blasting treatment and/or leveling treatment and treatment for contact with a solution are performed, the solution contains Cu etc. in a predetermined amount, the pH is −1.5 or more and less than 7, a solution temperature is 15° C. or more and 100° C. or less, and the time during which the steel sheet is dipped in the solution is 5 seconds or more and 200 seconds or less.

公开(公告)号：US20220098688A1

公开(公告)日：2022-03-31

申请号：US17421562

申请日：2020-01-08

Applicant: NIPPON STEEL CORPORATION

Inventor： Ichiro TANAKA ,  Ryutaro YAMAGATA ,  Nobusato MORISHIGE ,  Takashi KATAOKA ,  Masaru TAKAHASHI

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

Abstract: Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to the steel sheet is provided. The grain-oriented electrical steel sheet is provided with a base steel sheet having a chemical composition containing C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having Mg2 SiO4 as a main constituent formed on a surface of the base steel sheet. A peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction is present in a range of 2.0 to 12.0 μm from a surface of the primary coating to the thickness direction. A sum of perimeters of the Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 μm/μm2, and a number density of Al oxides is 0.02 to 0.20/μm2.

公开(公告)号：US20220002831A1

公开(公告)日：2022-01-06

申请号：US17421309

申请日：2020-01-08

Applicant: NIPPON STEEL CORPORATION

Inventor： Nobusato MORISHIGE ,  Ryutaro YAMAGATA ,  Ichiro TANAKA ,  Takashi KATAOKA ,  Haruhiko ATSUMI ,  Yoshihiro SUWA ,  Kazumi MIZUKAMI

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

Abstract: Grain-oriented electrical steel sheet excellent in coating adhesion and magnetic properties is provided. The method for manufacturing grain-oriented electrical steel sheet excellent in coating adhesion and magnetic properties includes a process of heating to 1280° C. or more and hot rolling a slab containing, by mass %, Bi and a predetermined composition of constituents and having a balance of Fe and impurities so as to obtain hot rolled steel sheet, a process, after hot rolling annealing the hot rolled steel sheet, of cold rolling it one time or cold rolling it two times or more with process annealing performed interposed so as to obtain cold rolled steel sheet, a process of rapidly heating then decarburization annealing the steel sheet, a process of coating the surface of the cold rolled steel sheet after decarburization annealing with an annealing separator containing predetermined compounds including sulfates or sulfides and having MgO as its main constituent, then performing finish annealing, a process of performing strictly controlled finish annealing, and a process of coating an insulating coating, then performing flattening annealing.

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.