公开(公告)号：US20220341009A1

公开(公告)日：2022-10-27

申请号：US17761043

申请日：2020-09-17

Applicant: NIPPON STEEL CORPORATION

Inventor： Masato YASUDA ,  Yoshihiro ARITA ,  Takashi KATAOKA ,  Kenichi MURAKAMI ,  Takeo ARAMAKI ,  Shinya YANO

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

Abstract: The purpose of the present invention is to provide a method for manufacturing a grain-oriented electrical steel sheet, whereby it becomes possible to manufacture a grain-oriented electrical steel sheet having further improved iron loss properties stably. (Solution) According to one aspect of the present invention, a method for manufacturing a grain-oriented electrical steel sheet is provided, the method being characterized by comprising a re-heating step, a hot rolling step, a hot-rolled sheet annealing step, a cold rolling step, a decarburization annealing step and a final annealing step, wherein the decarburization annealing step includes a heating step of heating a cold-rolled sheet from an inlet side temperature T0° C. to a soaking temperature T2° C. and a soaking step of keeping the temperature of the cold-rolled sheet at the soaking temperature T2° C., and the heating rate HR1 from the time point when the temperature of the cold-rolled sheet is an inlet side temperature T0° C. to the time point when the temperature of the cold-rolled sheet reaches a attained temperature T1° C. is 40° C./sec or more and the heating rate HR2 from the time point when the temperature of the cold-rolled sheet is the desired temperature T1° C. to the time point when the temperature of the cold-rolled sheet reaches the soaking temperature T2° C. is more than 15° C./sec to 30° C./sec in the heating in the decarburization annealing step.

公开(公告)号：US20220340991A1

公开(公告)日：2022-10-27

申请号：US17761055

申请日：2020-09-17

Applicant: NIPPON STEEL CORPORATION

Inventor： Masato YASUDA ,  Takeo ARAMAKI ,  Shinya YANO ,  Yoshihiro ARITA ,  Takashi KATAOKA ,  Kenichi MURAKAMI

IPC: C21D9/46 ,  C22C38/34 ,  C22C38/16 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00 ,  C21D8/12 ,  C21D8/00 ,  C21D6/00 ,  H01F1/147

Abstract: [Problem] To provide a grain-oriented electrical steel sheet which is further improved in terms of iron loss before magnetic domain control, while achieving a sufficient iron loss improvement effect even in the control of a heat-resistant magnetic domain where a sufficient iron loss improvement effect has not been achieved. [Solution] A grain-oriented electrical steel sheet according to one aspect of the present invention comprises abase steel sheet and a glass coating that is formed on the surface of the base steel sheet, and is characterized in that: the base steel sheet contains as chemical components, in mass %, 0.010% or less of C, from 2.00% to 4.00% of Si, from 0.05% to 1.00% of Mn, from 0.010% to 0.065% of Al, 0.004% or less of N and 0.010% or less of S, with the balance being made up of Fe and impurities; the oxygen concentration in the glass coating and the base steel sheet is 2,500 ppm or less; and if IAl_1 is the first peak intensity of Al and IAl_2 is the second peak intensity of Al in the concentration profile of Al, the relationship of mathematical formula (1) is satisfied. IAl_1

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：US20200181725A1

公开(公告)日：2020-06-11

申请号：US16793670

申请日：2020-02-18

Applicant: NIPPON STEEL CORPORATION

Inventor： Hiroyoshi YASHIKI ,  Kenichi MURAKAMI ,  Nobusato MORISHIGE ,  Hirotoshi TADA ,  Yoshiaki NATORI

IPC: C21D8/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D9/46 ,  B22D11/00 ,  H01F1/16 ,  C22C38/60 ,  B32B15/04 ,  B32B15/18

Abstract: A grain-oriented electrical steel sheet includes a steel layer and an insulation coating arranged in directly contact with the steel layer thereon. The steel layer includes, as a chemical composition, by mass %, 2.9 to 4.0% of Si, 2.0 to 4.0% of Mn, 0 to 0.20% of Sn, and 0 to 0.20% of Sb. In the steel layer, a silicon content and a manganese content expressed in mass % satisfy 1.2%≤Si−0.5×Mn≤2.0%, and a tin content and an antimony content expressed in mass % satisfy 0.005%≤Sn+Sb≤0.20%.