Grain-oriented electrical steel sheet and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-10011886-B2
Application number	US-201214347759-A
Country	US
Kind code	B2
Filing date	Sep 28, 2012
Priority date	Sep 28, 2011
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

A grain-oriented electrical steel sheet to which electron beam irradiation is applied, has a film and a thickness of t (mm), wherein no rust is produced on a surface of the steel sheet after a humidity cabinet test lasting 48 hours at a temperature of 50° C. in an atmosphere of 98% humidity, and iron loss W 17/50 after the electron beam irradiation is reduced by at least (−500 t 2 +200 t−6.5) % of the iron loss W 17/50 before the electron beam irradiation and is (5 t 2 −2 t+1.065) W/kg or less.

First claim

The invention claimed is:

1. A grain-oriented electrical steel sheet to which electron beam irradiation is applied, having a film and a thickness of t (mm), wherein no rust is produced on a surface of the steel sheet after a humidity cabinet test lasting 48 hours at a temperature of 50° C. in an atmosphere of 98% humidity, and an iron loss W 17/50 after the electron beam irradiation is reduced by at least (−500 t 2 +200 t−6.5) % of the iron loss W 17/50 before the electron beam irradiation and is (5 t 2 −2 t+1.065) W/kg or less.

2. The grain-oriented electrical steel sheet according to claim 1 , wherein the film includes a film formed from colloidal silica and phosphate, and a forsterite film that is a base film of the film formed from colloidal silica and phosphate.

3. A method of manufacturing a grain-oriented electrical steel sheet having a film, comprising: irradiating the grain-oriented electrical steel sheet with an electron beam in a direction intersecting a rolling direction, setting electron beam irradiation conditions such that an irradiation energy of the electron beam per unit area of 1 cm 2 is 1.0 Z J to 3.5 Z J and the irradiation energy of the electron beam per unit irradiation length of 1 m is 105 Z J or less, where an irradiation time per irradiation interval d (mm) of the electron beam is s 1 (ms), and Z =s 1 0.35 .

4. The method according to claim 3 , further comprising setting the irradiation interval d (mm) to 0.01 mm to 0.5 mm and setting the irradiation time s 1 (ms) to 0.003 ms to 0.1 ms.

5. The method according to claim 3 , wherein the film includes a film formed from colloidal silica and phosphate, and a forsterite film that is a base film of the film formed from colloidal silica and phosphate.

6. The method according to claim 4 , wherein the film includes a film formed from colloidal silica and phosphate, and a forsterite film that is a base film of the film formed from colloidal silica and phosphate.

Assignees

• Jfe Steel Corp

Inventors

• Takajo Shigehiro
• Yamaguchi Hiroi
• Omura Takeshi
• Inoue Hirotaka
• Okabe Seiji

Classifications

• C21D2201/05

  Grain orientation · CPC title

• C21D1/38

  Heating by cathodic discharges · CPC title

• C22C38/002

  containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60 · CPC title

• H01F1/18

  with insulating coating · CPC title

• C23C30/00

  Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process (C23C26/00, C23C28/00 take precedence) · CPC title