Grain oriented electrical steel sheet and producing method thereof

Patent metadata

Field	Value
Publication number	US-12123068-B2
Application number	US-201817258968-A
Country	US
Kind code	B2
Filing date	Jul 13, 2018
Priority date	Jul 13, 2018
Publication date	Oct 22, 2024
Grant date	Oct 22, 2024

Abstract

A grain oriented electrical steel sheet includes: by mass %, 0.010% or less of C; 2.50 to 4.00% of Si; 0.010% or less of acid soluble Al; 0.012% or less of N; 1.00% or less of Mn; 0.020% or less of S; and a balance comprising Fe and impurities, and has a tension-insulation coating at steel sheet surface and a SiO 2 intermediate oxide film layer with an average thickness of 1.0 nm to 1.0 μm at an interface between the tension-insulation coating and the steel sheet surface. In the grain oriented electrical steel, when a surface of the intermediate oxide film layer is analyzed by an infrared reflection spectroscopy, a peak intensity I A at 1250 cm −1 and a peak intensity I B at 1200 cm −1 satisfy I B /I A ≥0.010.

First claim

What is claimed is:

1. A grain oriented electrical steel sheet comprising:
a base steel sheet;
an intermediate oxide film layer which is arranged on the base steel sheet, includes SiO 2 , and has an average thickness of 1.0 nm to 1.0 μm; and
a tension-insulation coating which is arranged on the intermediate oxide film layer, wherein the base steel sheet includes: as a chemical composition, by mass %,
0.010% or less of C;
2.50 to 4.00% of Si;
0.010% or less of acid soluble Al;
0.012% or less of N;
1.00% or less of Mn;
0.020% or less of S; and
a balance comprising Fe and impurities, and
wherein, when a surface of the intermediate oxide film layer is analyzed by an infrared reflection spectroscopy, a peak intensity I A at 1250 cm −1 and a peak intensity I B at 1200 cm −1 satisfy a following formula (1),
I B /I A ≥0.010  (1).

2. The grain oriented electrical steel sheet according to claim 1 ,
wherein the base steel sheet further includes, as the chemical composition, by mass %, 0.001 to 0.010% of B.

3. The grain oriented electrical steel sheet according to claim 1 ,
wherein the base steel sheet further includes: as the chemical composition, by mass %, at least one selected from
0.01 to 0.20% of Sn;
0.01 to 0.50% of Cr; and
0.01 to 0.50% of Cu.

4. The grain oriented electrical steel sheet according to claim 2 ,
wherein the base steel sheet further includes: as the chemical composition, by mass %, at least one selected from
0.01 to 0.20% of Sn;
0.01 to 0.50% of Cr; and
0.01 to 0.50% of Cu.

5. The grain oriented electrical steel sheet according claim 1 ,
wherein a time differential curve f M (t) of a glow discharge optical emission spectrum of an element M (M: Mn, Al, B) in a surface of the intermediate oxide film layer satisfies a following formula (2),

∫
Ts
Tp

f
M

(
t
)

⁢
dt

>
0

(
2
)

Tp: a time t (second) corresponding to a local minimum value of a second-order time differential curve of a glow discharge optical emission spectrum of Si,
Ts: a time t (second) corresponding to an analysis starting point of a glow discharge optical emission spectrum of Si.

6. The grain oriented electrical steel sheet according to claim 2 ,
wherein a time differential curve f M (t) of a glow discharge optical emission spectrum of an element M (M: Mn, Al, B) in a surface of the intermediate oxide film layer satisfies a following formula (2),

∫
Ts
Tp

f
M

(
t
)

⁢
dt

>
0

(
2
)

Tp: a time t (second) corresponding to a local minimum value of a second-order time differential curve of a glow discharge optical emission spectrum of Si,
Ts: a time t (second) corresponding to an analysis starting point of a glow discharge optical emission spectrum of Si.

7. The grain oriented electrical steel sheet according to claim 3 ,
wherein a time differential curve f M (t) of a glow discharge optical emission spectrum of an element M (M: Mn, Al, B) in a surface of the intermediate oxide film layer satisfies a following formula (2),

∫
Ts
Tp

f
M

(
t
)

⁢
dt

>
0

(
2
)

Tp: a time t (second) corresponding to a local minimum value of a second-order time differential curve of a glow discharge optical emission spectrum of Si,
Ts: a time t (second) corresponding to an analysis starting point of a glow discharge optical emission spectrum of Si.

8. The grain oriented electrical steel sheet according to claim 4 ,
wherein a time differential curve f M (t) of a glow discharge optical emission spectrum of an element M (M: Mn, Al, B) in a surface of the intermediate oxide film layer satisfies a following formula (2),

∫
Ts
Tp

f
M

(
t
)

⁢
dt

>
0

(
2
)

Tp: a time t (second) corresponding to a local minimum value of a second-order time differential curve of a glow discharge optical emission spectrum of Si,
Ts: a time t (second) corresponding to an analysis starting point of a glow discharge optical emission spectrum of Si.

9. A method for producing the grain oriented electrical steel sheet according to claim 1 , the method comprising
an oxide film layer forming process of forming an intermediate oxide film layer on a steel sheet,
wherein,

Assignees

• Nippon Steel Corp

Inventors

• Kataoka Takashi
• Ushigami Yoshiyuki
• Nakamura Shuichi
• Fujii Hiroyasu
• Okumura Shunsuke

Classifications

• H01F1/14

  metals or alloys · CPC title

• C22C2202/02

  Magnetic · CPC title

• C22C38/18

  containing chromium · CPC title

• C22C38/16

  containing copper · CPC title

• C22C38/06

  containing aluminium · CPC title