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：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：US20210262052A1

公开(公告)日：2021-08-26

申请号：US17253795

申请日：2019-06-21

Applicant: NIPPON STEEL CORPORATION

Inventor： Tomoji KUMANO ,  Shinya YANO ,  Shingo OKADA ,  Akio OGURI ,  Shota MORIMOTO

IPC: C21D8/12 ,  C22C38/02 ,  C21D9/46

Abstract: Provided is a grain-oriented electrical steel sheet, the core loss characteristics of which have been significantly improved without causing a deterioration in magnetic flux density. The grain-oriented electrical steel sheet: comprises 2.5-3.5% by mass of Si with the balance being Fe and inevitable impurities; has a sheet thickness of 0.18-0.35 mm; has a metallographic structure including matrix grains of Goss-oriented secondary recrystallized grains after secondary-recrystallized annealing, wherein Goss-oriented crystal grains existing in the matrix and having a major (long) diameter of 5 mm or smaller exist in the metallographic structure at a frequency of 1.5 grains/cm2 to 8 grains/cm2; and has a magnetic flux density B8 of 1.88T or greater. As for the orientations of the Goss-oriented crystal grains having a major (long) diameter of 5 mm or smaller, the orientation of the Goss-oriented crystal grains deviate from the rolling direction by an angle of 7 degrees or smaller and by an angle of 5 degrees or smaller in terms of a simple average of an α angle and that of a ß angle, respectively.
α angle; the angle formed by the longitudinal direction and the projection of the [001] on specimen surface, and ß angle; the tilt of the [001] out of the specimen surface

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.