Non-Oriented Electrical Steel Sheet Having Superior Magnetic Properties and a Production Method Therefor

• US 20120267015A1
• Filed: 12/28/2010
• Published: 10/25/2012
• Est. Priority Date: 12/28/2009
• Status: Abandoned Application

• Current Assignee: Posco Holdings Incorporated
• Original Assignee: Posco Holdings Incorporated
• Inventors: Kim, Jae-Hoon, Kim, Jae-Kwan, Kim, Yong-Soo, Bong, Won-Seog
• Application Number:
  US13/514,342
• Publication Number:
  US 20120267015A1
• Time in Patent Office: Days
• US Class Current: 148/645
• CPC Class Codes: C21D 2211/004 Dispersions; Precipitations
• CPC Class Codes: C21D 8/12 during manufacturing of articles with special electromagnetic properties
• CPC Class Codes: C22C 38/001 containing N
• CPC Class Codes: C22C 38/002 containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
• CPC Class Codes: C22C 38/004 Very low carbon steels, i.e. having a carbon content of less than 0,01%
• CPC Class Codes: C22C 38/008 containing tin
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/14 containing titanium or zirconium
• CPC Class Codes: C22C 38/60 containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
• CPC Class Codes: H01F 1/16 in the form of sheets H01F1/147 takes precedence

Abstract

Provided are: a non-oriented electrical steel sheet having outstanding magnetic properties and comprising, as percentages by weight, from 1.0 to 3.0% of Al, from 0.5 to 2.5% of Si, from 0.5 to 2.0% of Mn, from 0.001 to 0.004% of N, from 0.0005 to 0.004% of S and a balance of Fe and other unavoidably incorporated impurities, wherein the Al, Mn, N and S are included so as to satisfy the compositional formulae {[Al]+[Mn]}≦3.5, 0.002≦{[N]+[S]}≦0.006, 300≦{([Al]+[Mn])/([N]+[S])}≦1,400; and a production method therefor. By optimising the Al, Si, Mn, N and S added components in this way, the distribution density of coarse inclusions is increased, thereby making it possible to improve crystal-grain growth properties and domain wall mobility and so produce the highest grade of non-oriented electrical steel sheet having superior magnetic properties, low hardness, and superior customer workability and productivity.

Claims

1. A non-oriented electrical steel sheet having superior magnetic properties, comprising 0.7˜

3.0% of Al, 0.2˜

3.5% of Si, 0.2˜

2.0% of Mn, 0.001˜

0.004% of N, 0.0005˜

0.004% of S, and a balance of Fe and other inevitable impurities by wt %, and satisfying at least one of Conditions (1), (2) and (3) below;

Condition (1);

0.7≦

[Al]≦

2.7, 0.2≦

[Si]≦

1.0, 0.2≦

[Mn]≦

1.7, {[Al]+[Mn]}≦

2.0, 0.002≦

{[N]+[S]}≦

0.006, 230≦

{([Al]+[Mn])/([N]+[S])}≦

1,000;

Condition (2);

1.0≦

[Al]≦

3.0, 0.5≦

[Mn]≦

2.0, {[Al]+[Mn]}≦

3.5, 0.002≦

{[N]+[S]}≦

0.006, 300≦

{([Al]+[Mn])/([N]+[S])}1,400; and

Condition (3);

1.0≦

[Al]≦

3.0, 2.3≦

[Si]≦

3.5, 0.5≦

[Mn]≦

2.0, {[Al]+[Mn]}≦

3.5, 0.002≦

{[N]+[S]}≦

0.006, 300≦

{([Al]+[Mn])/([N]+[S])}≦

1,400,

wherein [Al], [Si], [Mn], [N] and [S] indicate amounts (wt %) of Al, Si, Mn, N and S, respectively.

2. The non-oriented electrical steel sheet of claim 1, which satisfies Condition (1) and wherein the amounts of Al, Si and Mn satisfy Relation (1) below.

Relation (1):

1.0≦

{[Al]+[Si]+[Mn]/2}≦

2.0

3. The non-oriented electrical steel sheet of claim 1, wherein the amounts of Al and Mn satisfy Relation (2) below.

Relation (2):

1≦

[Al]/[Mn]≦

8

4. The non-oriented electrical steel sheet of claim 2, wherein a cross-sectional Vickers hardness (Hv1) is 140 or less.

5. The non-oriented electrical steel sheet of claim 1, which satisfies Condition (2) and wherein the amounts of Al, Si and Mn satisfy Relation (3) below.

Relation (3):

1.7≦

{[Al]+[Si]+[Mn]/2}≦

5.5

6. The non-oriented electrical steel sheet of claim 1, which satisfies Condition (2) and wherein the amounts of Al and Si satisfy Relation (4) below.

Relation (4):

0.6≦

[Al]/[Si]≦

4.0

7. The non-oriented electrical steel sheet of claim 5, wherein a cross-sectional Vickers hardness (Hv1) is 190 or less.

8. The non-oriented electrical steel sheet of claim 1, which satisfies Condition (3) and wherein the amounts of Al, Si and Mn satisfy Relation (5) below.

Relation (5):

3.0≦

{[Al]+[Si]+[Mn]/2}≦

56.5

9. The non-oriented electrical steel sheet of claim 8, wherein a cross-sectional Vickers hardness (Hv1) is 225 or less.

10. The non-oriented electrical steel sheet of claim 1, wherein an inclusion comprising a nitride and a sulfide alone or a combination thereof is formed in the steel sheet, and a distribution density of the inclusion having an average size of 300 nm or more is equal to or greater than 0.02 number/mm².

11. The non-oriented electrical steel sheet of claim 1, further comprising 0.2% or less of P.

12. The non-oriented electrical steel sheet of claim 11, wherein an inclusion comprising a nitride and a sulfide alone or a combination thereof is formed in the steel sheet, and a distribution density of the inclusion having an average size of 300 nm or more is equal to or greater than 0.02 number/mm².

13. The non-oriented electrical steel sheet of claim 1, further comprising at least one of 0.005˜

0.2% of Sn and 0.005˜

0.1% of Sb.

14. The non-oriented electrical steel sheet of claim 13, wherein an inclusion comprising a nitride and a sulfide alone or a combination thereof is formed in the steel sheet, and a distribution density of the inclusion having an average size of 300 nm or more is equal to or greater than 0.02 number/mm².

15. A non-oriented electrical steel sheet having superior magnetic properties, comprising 0.7˜

3.0% of Al, 0.2˜

3.5% of Si, 0.2˜

2.0% of Mn, 0.001˜

0.004% of N, 0.0005˜

0.004% of S, and a balance of Fe and other inevitable impurities by wt %, wherein an inclusion comprising a nitride and a sulfide alone or a combination thereof is formed in the steel sheet, and a distribution density of the inclusion having an average size of 300 nm or more is equal to or greater than 0.02 number/mm².

16. The non-oriented electrical steel sheet of claim 15, further comprising 0.2% or less of P.

17. The non-oriented electrical steel sheet of claim 15, further comprising at least one of 0.005˜

0.2% of Sn and 0.005˜

0.1% of Sb.

18. A method of producing a non-oriented electrical steel sheet having superior magnetic properties, comprising subjecting a slab comprising 0.7˜

3.0% of Al, 0.2˜

3.5% of Si, 0.2˜

2.0% of Mn, 0.001˜

0.004% of N, 0.0005˜

0.004% of S, and a balance of Fe and other inevitable impurities by wt % and satisfying at least one of Conditions (1), (2) and (3) below to heating, hot rolling, cold rolling, and final annealing at 750˜

1100°

C.;

Condition (1);

0.7≦

[Al]≦

2.7, 0.2≦

[Si]≦

1.0, 0.2≦

[Mn]≦

1.7, {[Al]+[Mn]}≦

2.0, 0.002≦

{[N]+[S]}≦

≦

0.006, 230≦

{([Al]+[Mn])/([N]+[S])}≦

1,000;

Condition (2);

1.0≦

[Al]≦

3.0, 0.5≦

[Si]≦

2.5, 0.5≦

[Mn]≦

2.0, {[Al]+[Mn]}≦

3.5, 0.002≦

{[N]+[S]}≦

0.006, 300≦

{([Al]+[Mn])/([N]+[S])}≦

1,400; and

Condition (3);

1.0≦

[Al]≦

3.0, 2.3≦

[Si]≦

3.5, 0.5≦

[Mn]≦

2.0, {[Al]+[Mn]}≦

3.5, 0.002≦

{[N]+[S]}≦

0.006, 300≦

{([Al]+[Mn])/([N]+[S])}≦

1,400,

wherein [Al], [Si], [Mn], [N] and [S] indicate amounts (wt %) of Al, Si, Mn, N and S, respectively.

19. The method of claim 18, wherein the slab satisfies Condition (1) and the amounts of Al, Si and Mn satisfy Relation (1) below.

Relation (1):

1.0≦

{[Al]+[Si]+[Mn]/2}≦

2.0

20. The method of claim 18, wherein the amounts of Al and Mn satisfy Relation (2) below.

Relation (2):

1≦

[Al]/[Mn]≦

8

21. The method of claim 18, wherein the slab satisfies Condition (2) and the amounts of Al, Si and Mn satisfy Relation (3) below.

Relation (3):

1.7≦

{[Al]+[Si]+[Mn]/2}≦

5.5

22. The method of claim 18, wherein the slab satisfies Condition (2) and the amounts of Al and Si satisfy Relation (4) below.

Relation (4):

0.6≦

[Al]/[Si]≦

4.0

23. The method of claim 18, wherein the slab satisfies Condition (3) and the amounts of Al, Si and Mn satisfy Relation (5) below.

Relation (5):

3.0≦

{[Al]+[Si]+[Mn]/2}≦

6.5

24. The method of claim 18, wherein an inclusion comprising a nitride and a sulfide alone or a combination thereof is formed in the steel sheet subjected to final annealing, and a distribution density of the inclusion having an average size of 300 nm or more is equal to or greater than 0.02 number/mm².

25. The method of claim 18, wherein the slab is prepared by adding 0.3˜

0.5% of Al to perform deoxidation, adding remaining alloy elements, and maintaining a temperature at 1,500˜

1,600°

C.

26. The method of claim 18, wherein annealing of a hot rolled sheet is performed between the hot rolling and the cold rolling.

27. The method of claim 18, wherein the slab further comprises 0.2% or less of P.

28. The method of claim 27, wherein an inclusion comprising a nitride and a sulfide alone or a combination thereof is formed in the steel sheet, and a distribution density of the inclusion having an average size of 300 nm or more is equal to or greater than 0.02 number/mm².

29. The method of claim 18, wherein the slab further comprises at least one of 0.005˜

0.2% of Sn and 0.005˜

0.1% of Sb.

30. The method of claim 29, wherein an inclusion comprising a nitride and a sulfide alone or a combination thereof is formed in the steel sheet, and a distribution density of the inclusion having an average size of 300 nm or more is equal to or greater than 0.02 number/mm².

31. A non-oriented electrical steel sheet slab, comprising 0.7˜

3.0% of Al, 0.2˜

3.5% of Si, 0.2˜

2.0% of Mn, 0.001˜

0.004% of N, 0.0005˜

0.004% of S, and a balance of Fe and other inevitable impurities by wt %, and satisfying at least one of Conditions (1), (2) and (3) below;

Condition (1);

0.7≦

[Al]≦

2.7, 0.2≦

[Si]≦

1.0, 0.2≦

[Mn]≦

1.7, {[Al]+[Mn]}≦

2.0, 0.002≦

{[N]+[S]}≦

0.006, 230≦

{([Al]+[Mn])/([N]+[S])}≦

1,000;

Condition (2);

1.0≦

[Al]≦

3.0, 0.5≦

[Si]≦

2.5, 0.5≦

[Mn]≦

2.0, {[Al]+[Mn]}≦

3.5, 0.002≦

{[N]+[S]}≦

0.006, 300≦

{([Al]+[Mn])/([N]+[S])}≦

1,400; and

Condition (3);

1.0≦

[Al]≦

3.0, 2.3≦

[Si]≦

3.5, 0.5≦

[Mn]≦

2.0, {[Al]+[Mn]}≦

3.5, 0.002≦

{[N]+[S]}≦

0.006, 300≦

{([Al]+[Mn])/([N]+[S])}≦

1,400,

wherein [Al], [Si], [Mn], [N] and [S] indicate amounts (wt %) of Al, Si, Mn, N and S, respectively.

32. The non-oriented electrical steel sheet slab of claim 31, which satisfies Condition (1) and wherein the amounts of Al, Si and Mn satisfy Relation (1) below.

Relation (1):

1.0≦

{[Al]+[Si]+[Mn]/2}≦

2.0

33. The non-oriented electrical steel sheet slab of claim 31, wherein the amounts of Al and Mn satisfy Relation (2) below.

Relation (2):

1≦

[Al]/[Mn]≦

8

34. The non-oriented electrical steel sheet slab of claim 31, which satisfies Condition (2) and wherein the amounts of Al, Si and Mn satisfy Relation (3) below.

Relation (3):

1.7≦

{[Al]+[Si]+[Mn]/2}≦

5.5

35. The non-oriented electrical steel sheet slab of claim 31, which satisfies Condition (2) and wherein the amounts of Al and Si satisfy Relation (4) below.

Relation (4):

0.6≦

[Al]/[Si]≦

4.0

36. The non-oriented electrical steel sheet slab of claim 31, which satisfies Condition (3) and wherein the amounts of Al, Si and Mn satisfy Relation (5) below.

Relation (5):

3.0≦

{[Al]+[Si]+[Mn]/2}≦

6.5

37. The non-oriented electrical steel sheet slab of claim 31, further comprising 0.2% or less of P.

38. The non-oriented electrical steel sheet slab of claim 31, further comprising at least one of 0.005˜

0.2% of Sn and 0.005˜

0.1% of Sb.

39. A method of producing a non-oriented electrical steel sheet slab, comprising adding 0.3˜

0.5% of Al to molten steel to perform deoxidation, adding a remainder of Al and Si and Mn, and maintaining a temperature of the molten steel at 1,500˜

1,600°

C., thus obtaining the slab comprising 0.7˜

3.0% of Al, 0.2˜

3.5% of Si, 0.2˜

2.0% of Mn, 0.001˜

0.004% of N, 0.0005˜

0.004% of S, and a balance of Fe and other inevitable impurities by wt %, and satisfying at least one of Conditions (1), (2) and (3) below;

Condition (1);

0.7≦

[Al]≦

2.7, 0.2≦

[Si]≦

1.0, 0.2≦

[Mn]≦

1.7, {[Al]+[Mn]}≦

2.0, 0.002≦

{[N]+[S]}≦

0.006, 230≦

{([Al]+[Mn])/([N]+[S])}≦

1,000;

Condition (2);

1.0≦

[Al]≦

3.0, 0.5≦

[Si]≦

2.5, 0.5≦

[Mn]≦

2.0, {[Al]+[Mn]}≦

3.5, 0.002≦

{[N]+[S]}≦

0.006, 300≦

{([Al]+[Mn])/([N]+[S])}≦

1,400; and

Condition (3);

1.0≦

[Al]≦

3.0, 2.3[Si]≦

3.5, 0.5≦

[Mn]≦

2.0, {[Al]+[Mn]}≦

3.5, 0.002≦

{[N]+[S]}≦

0.006, 300≦

{([Al]+[Mn])/([N]+[S])}≦

1,400,

wherein [Al], [Si], [Mn], [N] and [S] indicate amounts (wt %) of Al, Si, Mn, N and S, respectively.

40. The method of claim 39, wherein the slab further comprises 0.2% or less of P.

41. The method of claim 39, wherein the slab further comprises at least one of 0.005˜

0.2% of Sn and 0.005˜

0.1% of Sb.