公开(公告)号：US20230392223A1

公开(公告)日：2023-12-07

申请号：US18031246

申请日：2021-07-26

Applicant: JFE STEEL CORPORATION

Inventor： Makoto WATANABE ,  Takashi TERASHIMA ,  Karin KOKUFU

IPC: C21D6/00 ,  C22C38/02 ,  C22C38/04 ,  C21D9/46

CPC classification number: C21D6/008 ,  C22C38/02 ,  C22C38/04 ,  C21D9/46 ,  C21D2201/05

Abstract: A grain oriented electrical steel sheet has excellent insulation property and includes: a steel sheet; and a coating disposed on each of both surfaces of the steel sheet, wherein an interlaminar current value after a rubbing test is not more than 0.10 A, the rubbing test being conducted by stacking two sheets of the grain oriented electrical steel sheet and rubbing the two sheets against each other to make 90 reciprocations under conditions of a surface pressure of 200 Pa, a rubbing speed of 0.10 m/s, and a reciprocating stroke of 50 mm.

公开(公告)号：US20220098697A1

公开(公告)日：2022-03-31

申请号：US17426729

申请日：2020-01-30

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi IMAMURA ,  Makoto WATANABE

IPC: C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/12 ,  C22C38/42 ,  C22C38/48 ,  C22C38/60 ,  C21D8/12

Abstract: Provided are a grain-oriented electrical steel sheet having excellent iron loss property without using magnetic domain refining treatment and an iron core produced using the same. The steel sheet comprises: a predetermined chemical composition; and a steel microstructure in which: crystal grains are made up of coarse secondary recrystallized grains of 5.0 mm or more, fine grains of more than 2.0 mm and less than 5.0 mm contained at a frequency of 0.2 to 5 grains per cm2, and very fine grains of 2.0 mm or less; for each coarse secondary recrystallized grain extending through the sheet in a thickness direction, an area ratio of a region in which projected surfaces of exposed areas of the coarse secondary recrystallized grain on a front side and a back side of the sheet coincide with each other to each of the exposed areas is 95% or more.

公开(公告)号：US20200283863A1

公开(公告)日：2020-09-10

申请号：US16648663

申请日：2018-09-25

Applicant: JFE STEEL CORPORATION

Inventor： Kunihiro SENDA ,  Makoto WATANABE ,  Seiji OKABE ,  Souichiro YOSHIZAKI

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

Abstract: Further lower iron loss can be achieved in a grain-oriented electrical steel sheet including: a predetermined film mainly composed of forsterite on a front and back surfaces thereof; and a plurality of grooves on the front surface thereof, in which the plurality of grooves have an average depth of 6% or more of a thickness of the steel sheet and are spaced a distance of 1 mm to 15 mm from respective adjacent grooves, the steel sheet has a specific magnetic permeability μr15/50 of 35000 or more when subjected to alternating current magnetization at a frequency of 50 Hz and a maximum magnetic flux density of 1.5 T, and the steel sheet includes isolated parts having a presence frequency of 0.3/μm or less, the isolated parts being separated from a continuous part of the film in an interface between the steel sheet and the film in a cross section orthogonal to the rolling direction of the steel sheet.

公开(公告)号：US20180030559A1

公开(公告)日：2018-02-01

申请号：US15549742

申请日：2016-02-12

Applicant: JFE STEEL CORPORATION

Inventor： Masanori UESAKA ,  Makoto WATANABE ,  Shigehiro TAKAJO

IPC: C21D8/12 ,  C22C38/02 ,  C21D9/46 ,  H01F27/245 ,  C21D6/00 ,  C21D3/04 ,  B05D7/14 ,  H01F1/18 ,  C22C38/04 ,  C21D8/00

CPC classification number: C21D8/1294 ,  B05D7/14 ,  C21D3/04 ,  C21D6/005 ,  C21D6/008 ,  C21D8/005 ,  C21D8/12 ,  C21D8/1255 ,  C21D8/1272 ,  C21D8/1283 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C2202/02 ,  C23C22/00 ,  H01F1/16 ,  H01F1/18 ,  H01F27/245

Abstract: In a grain-oriented electrical steel sheet including: a steel substrate; a ceramic base film; and an insulating coating, critical damage shear stress τ between the base film and the steel substrate is 50 MPa or more. Thus, a grain-oriented electrical steel sheet having excellent insulation property, stacking factor, and magnetic property is provided without coating damage even when magnetic domain refining treatment by thermal strain is performed.

公开(公告)号：US20220195553A1

公开(公告)日：2022-06-23

申请号：US17593560

申请日：2020-03-26

Applicant: JFE STEEL CORPORATION

Inventor： Hiroi YAMAGUCHI ,  Takashi TERASHIMA ,  Makoto WATANABE

IPC: C21D9/46 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/12 ,  C21D8/00 ,  C21D6/00 ,  H01F1/147 ,  H01F41/02

Abstract: Provided is a method of producing a grain-oriented electrical steel sheet having uniform and good coating properties and magnetic properties throughout the length and/or width of the steel sheet. The method comprises: subjecting a steel slab to hot rolling, to cold rolling once or twice or more with intermediate annealing therebetween, and to primary recrystallization annealing; applying a liquid or slurry annealing separator to a resultant steel sheet; and thereafter coiling the steel sheet and subjecting the steel sheet to final annealing, wherein, before, after, or simultaneously with the application of the annealing separator, an additive for changing a composition of the annealing separator is adhered to the steel sheet at a weight ratio of 15% or less to a total of the annealing separator and the additive so as to vary the composition of the annealing separator in a longitudinal direction and/or width direction of the steel sheet.

公开(公告)号：US20220074012A1

公开(公告)日：2022-03-10

申请号：US17417375

申请日：2019-12-26

Applicant: JFE STEEL CORPORATION

Inventor： Takashi TERASHIMA ,  Makoto WATANABE ,  Toshito TAKAMIYA ,  Karin KOKUFU

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

Abstract: Provided is an annealing separator with which a grain-oriented electrical steel sheet having a forsterite film with excellent appearance uniformity and adhesion can be obtained. The annealing separator for grain-oriented electrical steel sheet comprises: magnesia that contains 0.05 mass % or more and 0.20 mass % or less of B and 0.01 mass % or more and 0.10 mass % or less of P, and titanium oxide in 1.0 part by mass or more and 10.0 parts by mass or less per 100 parts by mass of the magnesia where the titanium oxide contains one or more types of alkali metals in a total amount of 0.0050 mass % or more and 0.50 mass % or less, where an amount of P adsorbed on per 1 g of the titanium oxide is 1.5×10−4 g or more and 1.0×10−3 g or less.

公开(公告)号：US20200370153A1

公开(公告)日：2020-11-26

申请号：US16957723

申请日：2018-12-27

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi IMAMURA ,  Makoto WATANABE

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

Abstract: Disclosed is a grain-oriented electrical steel sheet that has excellent high-frequency iron loss properties and blanking workability. The steel sheet includes: steel components including, by mass %, Si: 1.5-8.0%, Mn: 0.02-1.0%, and at least one selected from Sn: 0.010-0.400%, Sb: 0.010-0.400%, Mo: 0.010-0.200%, and P: 0.010-0.200%; and crystal grains including coarse secondary recrystallized grains having an average grain size of 5 mm or more and fine grains having a grain size of 0.1-2.0 mm, wherein at least some of the coarse secondary recrystallized grains penetrate the steel sheet in a thickness direction and are respectively exposed on front and back surfaces of the steel sheet such that projection planes of the exposed surfaces of these coarse secondary recrystallized grains on the front and back surfaces form an overlapping region, and the fine grains are present at a number density per unit area of 0.6-40 pieces/cm2.

公开(公告)号：US20200010917A1

公开(公告)日：2020-01-09

申请号：US16483829

申请日：2018-01-17

Applicant: JFE STEEL CORPORATION

Inventor： Takashi TERASHIMA ,  Takumi UMADA ,  Makoto WATANABE ,  Toshito TAKAMIYA

IPC: C21D8/12 ,  C22C38/00

Abstract: In a grain-oriented electrical steel sheet, comprising magnetic domains refined by a plurality of linear grooves in a surface of a steel sheet, each of the linear grooves is provided on its floor with a plurality of recessed parts aligned in a direction in which the linear groove extends, at a predetermined interval p (μm), and the recessed part is made to have a predetermined depth d (μm). In this way, it is possible to provide a grain-oriented electrical steel sheet having further improved iron loss properties while having reduced magnetic flux density reduction.

公开(公告)号：US20180371621A1

公开(公告)日：2018-12-27

申请号：US16117427

申请日：2018-08-30

Applicant: JFE STEEL CORPORATION

Inventor： Takashi TERASHIMA ,  Makoto WATANABE ,  Masanori UESAKA ,  Ryuichi SUEHIRO ,  Toshito TAKAMIYA

IPC: C23C22/12 ,  C21D6/00 ,  C21D9/46 ,  C23C22/22 ,  H01F1/18 ,  C23C22/74 ,  C23C22/18 ,  C21D8/12 ,  C23C22/78 ,  C23C22/20

CPC classification number: C23C22/12 ,  C21D6/008 ,  C21D8/1288 ,  C21D9/46 ,  C23C22/182 ,  C23C22/188 ,  C23C22/20 ,  C23C22/22 ,  C23C22/74 ,  C23C22/78 ,  H01F1/18

Abstract: Provided is a treatment solution for chromium-free tension coating that can simultaneously achieve excellent moisture absorption resistance and a high iron loss reduction effect obtained by imparting sufficient tension, by using an inexpensive Ti source instead of expensive Ti chelate. The treatment solution for chromium-free tension coating contains: one or more of phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn; colloidal silica in an amount of 50 parts by mass to 120 parts by mass per 100 parts by mass of the phosphate in terms of solid content of SiO2; Ti source in an amount of 30 parts by mass to 50 parts by mass per 100 parts by mass of the phosphate in terms of solid content of TiO2; and H3PO4, and the number of moles of metallic elements in the phosphate and of phosphorus in the treatment solution satisfy: 0.20≤([Mg]+[Ca]+[Ba]+[Sr]+[Zn]+[Mn]+1.5[Al])/[P]≤0.45  (1).

公开(公告)号：US20170137633A1

公开(公告)日：2017-05-18

申请号：US15118428

申请日：2015-03-02

Applicant: JFE STEEL CORPORATION

Inventor： Takashi TERASHIMA ,  Makoto WATANABE ,  Masanori UESAKA ,  Ryuichi SUEHIRO ,  Toshito TAKAMIYA

IPC: C09D1/00 ,  C23C30/00

CPC classification number: C09D1/00 ,  C23C22/08 ,  C23C22/12 ,  C23C22/18 ,  C23C22/20 ,  C23C22/22 ,  C23C22/74 ,  C23C30/00

Abstract: By using a treatment solution for chromium-free insulating coating containing one or more of a Mg phosphate, Ca phosphate, Ba phosphate, Sr phosphate, Zn phosphate, Al phosphate, and Mn phosphate, wherein colloidal silica is contained in an amount of 50 to 120 parts by mass per 100 parts by mass of the phosphate in terms of solid content of SiO2, and a water-soluble metal salt of Mg, Ca, Ba, Sr, Zn, Al, and Mn is contained to adjust the molar ratio between M2+(=Mg,Ca,Ba,Sr,Zn,Mn) and/or M3+(=Al) which are metallic elements contained in the treatment solution and P to a range of 0.6≦(M2++1.5×M3+)/P≦1.0, chromium-free insulating coating that provides excellent moisture absorption resistance for a long period and has a sufficient iron loss reduction effect can be obtained at low cost while minimizing the amount of expensive Ti such as Ti chelate used or without using such expensive Ti at all.