Grain-oriented silicon steel with low core loss and manufacturing method therefore

Patent metadata

Field	Value
Publication number	US-11638971-B2
Application number	US-201816496541-A
Country	US
Kind code	B2
Filing date	Jan 24, 2018
Priority date	Mar 27, 2017
Publication date	May 2, 2023
Grant date	May 2, 2023

Abstract

A grain-oriented silicon steel with low iron loss, wherein the silicon steel is provided with a plurality of grooves on its surface, each of the grooves is 10-60 μm in width and 5-40 μm in depth, and the spacing between adjacent grooves is 1-10 mm. The manufacturing method therefor comprises: scoring the surface of the grain-oriented silicon steel with low iron loss by using a laser in order to form the grooves. The grain-oriented silicon steel with low iron loss can maintain the magnetic domain refining effect in a stress-relief annealing process, and avoid the introduction of more residual stress.

First claim

The invention claimed is:

1. A grain-oriented silicon steel with low iron loss, wherein the grain-oriented silicon steel comprises a plurality of grooves on a surface of said grain-oriented silicon steel, and each groove is 10-60 μm in width and 5-40 μm in depth, and the spacing between adjacent grooves is 1-10 mm; and wherein
the grain-oriented silicon steel has ΔP 17/50 %, a relative change rate of iron loss before and after stress-relief annealing, of 5% or less, and wherein

Δ
⁢

⁢

P

17
/
50

⁢

⁢
%

=

P

17
/
50

⁡

(

after
⁢

⁢
annealing

)

-

P

17
/
50

⁡

(

before
⁢

⁢
annealing

)

P

17
/
50

⁡

(

after
⁢

⁢
annealing

)

,

P 17/50 is an iron loss of a grain-oriented silicon steel sheet, in unit of W/kg, and wherein the P 17/50 after annealing >P 17/50 before annealing.

2. The grain-oriented silicon steel with low iron loss of claim 1 , wherein an angle formed between the groove and the width direction of a steel sheet is not more than 30°.

3. The grain-oriented silicon steel with low iron loss of claim 1 , wherein the grooves are formed by laser scoring.

4. The grain-oriented silicon steel with low iron loss of claim 1 , wherein one or both the surfaces of the grain-oriented silicon steel have the grooves.

5. A method for producing a grain-oriented silicon steel with low iron loss, comprising the steps of scoring a surface of the grain-oriented silicon steel with a laser to form grooves, and each groove is 10-60 μm in width and 5-40 μm in depth, and the spacing between adjacent grooves is 1-10 mm;
wherein an average single-pulse energy flux density J F and the pulse width t p of the laser satisfy the following relationship:
0.005 ≤t p √{square root over ( J F )}≤1,and

wherein the unit of the pulse width t p is ns; and the unit of J F is J/mm 2 , and
wherein the average single pulse energy flux density J F is expressed as:

J
F

=

P

f
r

⁢
S

,

wherein P is the output power of the laser in W; f r is the repetition frequency of laser in Hz; S is the spot area in mm 2 .

6. The method for producing a grain-oriented silicon steel with low iron loss of claim 5 , wherein an angle formed between the groove and the width direction of a steel sheet is not more than 30°.

7. The method for producing a grain-oriented silicon steel with low iron loss of claim 5 , wherein the laser is one or more selected from a CO 2 laser, a solid laser, and a fiber optic laser.

8. The method for producing a grain-oriented silicon steel with low iron loss of claim 5 , wherein the laser has an average single-pulse instantaneous peak power density of 2.0×10 6 W/mm 2 or more.

9. The method for producing a grain-oriented silicon steel with low iron loss of claim 5 , wherein the laser has a wavelength of 1066 nm or less.

Assignees

• Baoshan Iron & Steel

Inventors

• Wu Meihong
• Zhao Zipeng
• Li Guobao
• Shen Kanyi
• Hu Zhuochao
• Ling Chen
• Sun Huande
• Zhang Huabing

Classifications

• C21D9/46

  for sheet metals · CPC title

• B23K26/364 Primary

  for making a groove or trench, e.g. for scribing a break initiation groove · CPC title

• H01F41/0233

  Manufacturing of magnetic circuits made from sheets (magnetic cores made from sheets H01F27/245; soft magnetic alloys in the form of sheets H01F1/16) · CPC title

• B23K26/40

  taking account of the properties of the material involved · CPC title

• B23K2103/04

  Steel {or steel} alloys · CPC title