公开(公告)号：US20210317319A1

公开(公告)日：2021-10-14

申请号：US17264129

申请日：2019-06-19

Applicant: JFE STEEL CORPORATION

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

IPC: C09D1/00 ,  C23C26/00 ,  B05D1/28 ,  B05D3/02 ,  B05D7/14 ,  H01F1/147

Abstract: An insulating coating treatment liquid for forming a chromium-free insulating coating on a surface of a grain-oriented electrical steel sheet, the insulating coating treatment liquid including at least one phosphate salt selected from phosphate salts of any of Mg, Ca, Ba, Sr, Zn, Al, and Mn and including colloidal silica and particles of a metal-element-containing compound. A content of the colloidal silica in terms of SiO2, on a solids basis, is 50 to 120 parts by mass, and a content of the particles of a metal-element-containing compound in terms of elemental metal is 5 to 60 parts by mass, per 100 parts by mass of the at least one phosphate salt, and the insulating coating treatment liquid has a thixotropic index (TI) of 1.00 or greater and 10.00 or less.

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：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：US20210035718A1

公开(公告)日：2021-02-04

申请号：US16967945

申请日：2019-01-21

Applicant: JFE STEEL CORPORATION

Inventor： Takashi TERASHIMA ,  Masahiro SUEMUNE ,  Karin KOKUFU ,  Toshito TAKAMIYA

IPC: H01F1/147 ,  C23C28/04

Abstract: An insulating coating-attached electrical steel sheet has, on at least one surface, an insulating coating including an insulating tensile coating layer A. A tension applied to the steel sheet by an insulating tensile coating layer having a coating weight of M/2 from a surface of the insulating tensile coating layer A is 0.80×σA or more, where M is a weight of the insulating tensile coating layer A, and σA is the tension applied to the steel sheet by the insulating tensile coating layer A. The insulating coating-attached electrical steel sheet has excellent adhesion of the insulating coating. A method for manufacturing the insulating coating-attached electrical steel sheet is also provided.

公开(公告)号：US20250116005A1

公开(公告)日：2025-04-10

申请号：US18729961

申请日：2022-09-28

Applicant: JFE Steel Corporation

Inventor： Takashi TERASHIMA ,  Karin KOKUFU

IPC: C23C22/78 ,  C21D8/12 ,  C21D9/46 ,  C23C22/07 ,  C23C28/04

Abstract: An electrical steel sheet provided with an insulating coating is disclosed. A pre-treatment liquid to be used on an electrical steel sheet having a forsterite coating on a surface thereof before applying an insulating coating treatment liquid containing a phosphate is also disclosed. When a phosphate concentration of the pre-treatment liquid is defined as A mass % in terms of H3PO4, a refractive index R of the pre-treatment liquid satisfies Formula (1): 9.0×10−4×A+1.3340≤R   (1).

公开(公告)号：US20220074030A1

公开(公告)日：2022-03-10

申请号：US17417113

申请日：2019-12-26

Applicant: JFE STEEL CORPORATION

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

IPC: C22C38/18 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/00

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, a phosphate in 0.1 parts by mass or more and 1.0 part by mass or less in terms of P per 100 parts by mass of the magnesia, 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 0.050 mass % or more and 1.0 mass % or less, where an amount of P adsorbed on per 1 g of the titanium oxide is 1.0×10−4 g or less.

公开(公告)号：US20210269921A1

公开(公告)日：2021-09-02

申请号：US17269183

申请日：2019-06-27

Applicant: JFE STEEL CORPORATION

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

IPC: C23C22/07 ,  H01B13/06 ,  H01B3/00 ,  C23C22/82

Abstract: A production method for a treatment solution for forming an insulating coating. The method includes mixing a solution A containing, on a PO43− basis, 0.20 mol/L or more and 10 mol/L or less of at least one of (i) phosphoric acid and (ii) a phosphate salt, and containing, on a metal basis, less than 0.50 mol/L of one or more particulate metal compounds, and a solution B containing, on a metal basis, 0.50 mol/L or more and 20.0 mol/L or less of the one or more particulate metal compounds, and containing, on a PO43− basis, less than 0.20 mol/L of at least one of (i) phosphoric acid and (ii) a phosphate salt, and stirring with a turbine stator-type high-speed stirrer such that a peripheral speed of a turbine reaches 10 m/s or more within 60 seconds after starting the mixing of the solution A and the solution B.