Grain-oriented electrical steel sheet for low-noise transformer, and method of manufacturing said sheet

Patent metadata

Field	Value
Publication number	US-2017016085-A1
Application number	US-201515121791-A
Country	US
Kind code	A1
Filing date	Feb 24, 2015
Priority date	Feb 28, 2014
Publication date	Jan 19, 2017
Grant date	—

Abstract

A grain-oriented electrical steel sheet is subjected to magnetic domain refining treatment by irradiating a steel sheet surface with an electron beam having a beam diameter d of 0.40 mm or less, wherein a modulated irradiation line region is formed with repeating units connected to each other in the line region direction, a periodic distance of the repeating units in the modulated irradiation line region is ⅔×d mm to 2.5×d mm, a repeating interval of the modulated irradiation line region in the rolling direction is 4.0 mm to 12.5 mm, and intensity of the electron beam is not lower than an intensity with which long and narrow divided magnetic domains extending in the modulated irradiation line region direction are formed at least on an irradiated side, and not higher than an intensity with which coating damage does not occur and a plastic strain region is not formed on the irradiated side.

First claim

1 .- 6 . (canceled)

7 . A grain-oriented electrical steel sheet for a low-noise transformer subjected to magnetic domain refining treatment by irradiating a steel sheet surface with an electron beam having a beam diameter d of 0.40 mm or less in a line region extending in a direction intersecting a rolling direction, forming the irradiated line region into a modulated irradiation line region with repeating units, each unit comprising a retention region and a travelling region, and repeating a process to form the modulated irradiation line region at intervals in the rolling direction, wherein
the modulated irradiation line region is formed with repeating units connected to each other in the line region direction, a periodic distance of the repeating units in the modulated irradiation line region is ⅔×d mm to 2.5×d mm, a repeating interval of the modulated irradiation line region in the rolling direction is 4.0 mm to 12.5 mm, and intensity of the electron beam is not lower than an intensity with which long and narrow divided magnetic domains extending in the modulated irradiation line region direction are formed at least on an irradiated side, and not higher than an intensity with which coating damage does not occur and a plastic strain region is not formed on the irradiated side.

8 . The grain-oriented electrical steel sheet according to claim 7 , wherein an acceleration voltage of the electron beam is 100 kV or more.

9 . The grain-oriented electrical steel sheet according to claim 7 , wherein the repeating interval of the modulated irradiation line region in the rolling direction is 5.0 mm to 10 mm.

10 . A method of manufacturing a grain-oriented electrical steel sheet for a low-noise transformer comprising:
subjecting the steel sheet to magnetic domain refining treatment by irradiating a steel sheet surface with an electron beam having a beam diameter d of 0.40 mm or less in a line region extending in a direction intersecting a rolling direction, forming the irradiated line region into a modulated irradiation line region with repeating units, each comprising a retention region and a travelling region, and repeating a process to form the modulated irradiation line region at intervals in the rolling direction, wherein the modulated irradiation line region is formed with repeating units connected to each other in the line region direction, a periodic distance of the repeating units in the modulated irradiation line region is ⅔×d mm to 2.5×d mm, a repeating interval of the modulated irradiation line region in the rolling direction is 4.0 mm to 12.5 mm, and intensity of the electron beam is not lower than an intensity with which long and narrow divided magnetic domains extending in the modulated irradiation line region direction are formed at least on an irradiated side, and not higher than an intensity with which coating damage does not occur and a plastic strain region is not formed on the irradiated side.

11 . The method according to claim 10 , wherein an acceleration voltage of the electron beam is 100 kV or more.

12 . The method according to claim 10 , wherein the repeating interval of the modulated irradiation line region in the rolling direction is 5.0 mm to 10 mm.

13 . The grain-oriented electrical steel sheet according to claim 8 , wherein the repeating interval of the modulated irradiation line region in the rolling direction is 5.0 mm to 10 mm.

14 . The method according to claim 11 , wherein the repeating interval of the modulated irradiation line region in the rolling direction is 5.0 mm to 10 mm.

Assignees

• Jfe Steel Corp

Inventors

• Toda Hiroaki
• Takajo Shigehiro
• Komatsubara Michiro

Classifications

• C21D8/1216

  characterised by the working steps · CPC title

• C21D1/09

  by direct application of electrical or wave energy; by particle radiation · CPC title

• C21D9/46 Primary

  for sheet metals · CPC title

• C21D10/00

  Modifying the physical properties by methods other than heat treatment or deformation · CPC title

• C21D2201/05

  Grain orientation · CPC title