IRON-BASE AMORPHOUS ALLOY THIN STRIP EXCELLENT IN SOFT MAGNETIC PROPERTIES, IRON CORE MANUFACTURED BY USING SAID THIN STRIP, AND

• US 20040140016A1
• Filed: 12/04/2003
• Published: 07/22/2004
• Est. Priority Date: 04/05/2002
• Status: Active Grant

• Current Assignee: Nippon Steel Corporation
• Original Assignee: Nippon Steel Corporation
• Inventors: Sato, Yuichi, Sakamoto, Hiroaki
• Granted Patent: US 7,282,103 B2
• Time in Patent Office: Days
• US Class Current: 148/304
• CPC Class Codes: C22C 33/003 making amorphous alloys
• CPC Class Codes: C22C 45/02 with iron as the major constituent
• CPC Class Codes: H01F 1/15308 based on Fe/Ni H01F1/15325 takes precedence
• CPC Class Codes: H01F 41/0226 from amorphous ribbons

Abstract

The present invention provides an iron-base amorphous alloy thin strip excellent in soft magnetic properties, an iron core manufactured by using said thin strip, and a mother alloy for producing a rapidly cooled and solidified thin strip. More specifically, the present invention is an iron-base amorphous alloy thin strip produced by rapidly cooling and solidifying molten metal by ejecting it onto a moving cooling substrate through a pouring nozzle having a slot-shaped opening, characterized by having an ultra-thin oxide layer of a thickness in the range from 5 to 20 nm on one or both of the surfaces of the amorphous mother phase containing P in the range from 0.2 to 12 atomic %.

Claims

1. An iron-base amorphous alloy thin strip produced by rapidly cooling and solidifying molten metal by ejecting it onto a moving cooling substratum through a pouring nozzle having a slot-shaped opening, characterized by having an ultra-thin oxide layer of a thickness in the range from 5 to 20 nm on one or both of the surfaces of the amorphous mother phase containing P in the range from 0.2 to 12 atomic %.

2. An iron-base amorphous alloy thin strip according to claim 1, characterized by having a segregation layer containing P and/or S between said ultra-thin oxide layer and said amorphous mother phase.

3. An iron-base amorphous alloy thin strip according to claim 1, characterized in that said ultra-thin oxide layer has a bilaminar structure.

4. An iron-base amorphous alloy thin strip according to any one of claims 1 to 3, characterized by having an ultra-thin oxide layer on the surface of said thin strip at least on the side not touching the cooling substratum.

5. An iron-base amorphous alloy thin strip according to claim 2 or 4, characterized in that the thickness of said segregation layer is 0.2 nm or more.

6. An iron-base amorphous alloy thin strip according to claim 3 or 4, characterized in that both the laminas of said bilaminar ultra-thin oxide layer are amorphous oxide laminas.

7. An iron-base amorphous alloy thin strip according to claim 3 or 4, characterized in that, in said bilaminar ultra-thin oxide layer:

the first oxide lamina at the outermost surface of the thin strip is a mixed lamina consisting of crystalline and amorphous oxides; and

the second oxide lamina between said first oxide lamina and the amorphous mother phase is an amorphous oxide lamina.

8. An iron-base amorphous alloy thin strip according to claim 3 or 4, characterized in that, in said bilaminar ultra-thin oxide layer:

the first oxide lamina at the outermost surface of the thin strip is a crystalline oxide lamina; and

the second oxide lamina between said first oxide lamina and the amorphous mother phase is an amorphous oxide lamina.

9. An iron-base amorphous alloy thin strip according to any one of claims 1 to 8, characterized in that said ultra-thin oxide layer consists of Fe oxide, Si oxide, B oxide or a composite of these oxides.

10. An iron-base amorphous alloy thin strip according to any one of claims 7 to 9, characterized in that the crystalline oxide composing a part of said ultra-thin oxide layer is Fe oxide having a spinel structure.

11. An iron-base amorphous alloy thin strip according to any one of claims 3, 4 and 6 to 10, characterized in that the total thickness of said bilaminar ultra-thin oxide layer is in the range from 5 to 20 nm, the thickness of said first oxide lamina is in the range from 3 to 15 nm, and that of said second oxide lamina is in the range from 2 to 10 nm.

12. An iron-base amorphous alloy thin strip according to any one of claims 3, 4 and 6 to 10, characterized in that at least one or more elements of P, As, Sb, Bi, S, Se and Te segregate in said second oxide lamina.

13. An iron-base amorphous alloy thin strip according to any one of claims 1 to 12, characterized in that the thickness of said thin strip is in the range from 10 to 100 μ

m.

14. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties, the amorphous alloy thin strip consisting of the main elements of Fe, Co, Si, B, C and P and unavoidable impurities, characterized in that the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe_1-XCo_X (wherein 0.05≦

X≦

0.4), from 2 to less than 4% as to Si, from more than 5 to 16% as to B, from 0.02 to 4% as to C, and from 0.2 to 12% as to P.

15. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to claim 14, characterized in that the content of Fe_1-XCo_X (wherein 0.05≦

X≦

0.4) is in the range from more than 80 to 82 atomic %.

16. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to claim 14 or 15, characterized by having:

such soft magnetic properties that the values of B₈₀ after annealing are 1.37 T or more and the standard deviation of the values of B₈₀ is less than 0.1; and

such an annealing temperature characteristic that the value of Δ

T_A defined as Δ

T_A=T_Amax−

T_Amin is at least 80°

C., wherein T_Amax and T_Amin represent respectively the maximum and minimum annealing temperatures between which said soft magnetic properties are secured.

26. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to any one of claims 14 to 25, characterized in that the content of P is in the range from 1 to 12 atomic

32. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to any one of claims 14 to 19, 24, 25 and 27 to 30, characterized by having:

such a core loss characteristic that the core loss after annealing is 0.12 W/kg or less; and

such an annealing temperature characteristic that the value of Δ

T_B defined as Δ

T_B=T_Bmax−

T_Bmin is at least 60°

C., wherein T_Bmax and T_Bmin represent respectively the maximum and minimum annealing temperatures between which said core loss characteristic is secured.

34. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to any one of claims 14 to 16, 24, 25 and 27 to 30, characterized by having such an excellent embrittlement resistance that the fracture strain of the thin strip ε

_f defined as ε

_f=t/(D_f−

t) is 0.01 or more, wherein t represents the thickness of an annealed thin strip subjected to 180°

bend test and D_f the diameter of the bend at the time when the thin strip fractures.

35. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to any one of claims 14 to 34, characterized in that the content of B is in the range from more than 5 to less than 14 atomic %.

45. A wound iron core excellent in alternating current soft magnetic properties, characterized by:

being formed by toroidally winding an iron-base amorphous alloy thin strip according to any one of claims 14 to 44; and

then being annealed.

46. A laminated iron core excellent in alternating current soft magnetic properties, characterized by:

being formed by punching an iron-base amorphous alloy thin strip according to any one of claims 14 to 44 into sheets of a prescribed shape and laminating the sheets; and

then being annealed.

17. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties, the amorphous alloy thin strip consisting of the main elements of Fe, Ni, Si, B, C and P and unavoidable impurities, characterized in that the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe_1-YNi_Y (wherein 0.05≦

Y≦

0.2), from 2 to less than 4% as to Si, from more than 5 to 16% as to B, from 0.02 to 4% as to C, and from 0.2 to 12% as to P.

18. An iron-base amorphous alloy thin strip according to claim 17, characterized in that the content of Fe_1-YNi_Y (wherein 0.05≦

Y≦

0.2) is in the range from more than 80 to 82 atomic %.

19. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to claim 17 or 18, characterized by having:

such soft magnetic properties that the values of B₈₀ after annealing are 1.35 T or more and the standard deviation of the values of B₈₀ is less than 0.1;

such an annealing temperature characteristic that the value of Δ

T_A defined as Δ

T_A=T_Amax−

T_Amin is at least 80°

C., wherein T_Amax and T_Amin represent respectively the maximum and minimum annealing temperatures between which said soft magnetic properties are secured; and

such an excellent embrittlement resistance that the fracture strain of the thin strip ε

_f defined as ε

_f=t/(D_f−

t) is 0.015 or more, wherein t represents the thickness of an annealed thin strip subjected to 180°

bend test and D_f the diameter of the bend at the time when the thin strip fractures.

20. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties, the amorphous alloy thin strip being produced by rapidly cooling and solidifying molten alloy by ejecting it onto a moving cooling substrate through a pouring nozzle having a slot-shaped opening and consisting of the main elements of Fe, Si, B, C and P and unavoidable impurities, characterized in that:

the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe, from 2 to less than 4% as to Si, from 2 to 15% as to B, from 0.02 to 4% as to C, and from 1 to 14% as to P, while the content of B+P is maintained in the range from 12 to 20%; and

the value of (Wmax−

Wmin)/Wmin is 0.4 or less, wherein Wmax and Wmin represent respectively the maximum and minimum values of core loss after annealing at different positions across the width of the thin strip.

33. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to any one of claims 20 to 23, characterized by having such a core loss characteristic that the core loss after annealing is 0.12 W/kg or less.

36. An iron-base amorphous alloy thin strip excellent in alternating-current soft magnetic properties according to any one of claims 20 to 35, characterized in that the content of Fe is in the range from more than 80 to 82 atomic %.

21. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties, the amorphous alloy thin strip being produced by rapidly cooling and solidifying molten alloy by ejecting it onto a moving cooling substrate through a pouring nozzle having a slot-shaped opening and consisting of the main elements of Fe, Si, B, C and P and unavoidable impurities, characterized in that:

the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe, from 2 to less than 4% as to Si, from 2 to 15% as to B, from 0.02 to 4% as to C, and from 1 to 14% as to P, while the content of B+P is maintained in the range from 12 to 20%; and

said thin strip has such a good shape characteristic that the region where the number of the coarse air pockets 500 μ

m or more in length or 50 μ

m or more in width in 10/cm² or less is 80% or more in area percentage, the coarse air pockets inevitably forming at the surface of the thin strip on the side touching the cooling substratum.

22. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties, the amorphous alloy thin strip being produced by rapidly cooling and solidifying molten alloy by ejecting it onto a moving cooling substrate through a pouring nozzle having a slot-shaped opening and consisting of the main elements of Fe, Si, B, C and P and unavoidable impurities, characterized in that:

the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe, from 2 to less than 4% as to Si, from 2 to 15% as to B, from 0.02 to 4% as to C, and from 1 to 14% as to P, while the content of B+P is maintained in the range from 12 to 20%; and

said thin strip has such a good shape characteristic that the value of Δ

tdefined as Δ

t=tmax−

tmin is 5 μ

m or less, wherein tmax and tmin represent respectively the maximum and minimum thicknesses of the thin strip at arbitrary positions across the width of the thin strip.

23. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to claim 22, characterized in that the value of said Δ

tis 3 μ

m or less.

24. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties, the amorphous alloy thin strip consisting of the main elements of Fe, B, C and P and unavoidable impurities, characterized in that the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe, from more than 5 to 16% as to B, from 0.02 to 8% as to C, and from 0.2 to 12% as to P.

31. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to any one of claims 24, 25 and 27 to 30, characterized by having:

such soft magnetic properties that the values of B₈₀ after annealing are 1.35 T or more and the standard deviation of the values of B₈₀ is less than 0.1; and

such an annealing temperature characteristic that the value Δ

T_A defined as Δ

T_A=T_Amax−

T_Amin is at least 80°

C., wherein T_Amax and T_Amin represent respectively the maximum and minimum annealing temperatures between which said soft magnetic properties are secured.

25. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties, the amorphous alloy thin strip consisting of the main elements of Fe, Si, B, C and P and unavoidable impurities, characterized in that the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe, from 0.02 to less than 2% as to Si, from more than 5 to 16% as to B, from 0.02 to 8% as to C, and from 0.2 to 12% as to P.

27. An iron-base amorphous alloy thin strip excellent in alternating-current soft magnetic properties, the amorphous alloy thin strip consisting of the main elements of Fe, Si, B, C and M and unavoidable impurities, wherein M indicates one or more of As, Bi, S, Se and Te, characterized in that the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe, from 2 to less than 4% as to Si, from more than 5 to 16% as to B, from 0.02 to 4% as to C, and from 0.2 to 12% as to M.

29. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to claim 27, characterized in that the content of said M is in the range from 1 to 12 atomic %.

28. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties, the amorphous alloy thin strip consisting of the main elements of Fe, Si, B, C and P+M and unavoidable impurities, wherein M indicates one or more of As, Bi, S, Se and Te, characterized in that the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe, from 2 to less than 4% as to Si, from more than 5 to 16% as to B, from 0.02 to 4% as to C, and from 0.2 to 12% as to P+M.

30. An iron-base amorphous alloy thin strip excellent in alternating current soft magnetic properties according to claim 28, characterized in that the content of said P+M is in the range from 1 to 12 atomic %.

37. An iron-base amorphous alloy thin strip characterized in that:

the composition of said thin strip consists of the main elements of Fe, B, C and one or more of P, As, Bi, S, Se and Te, and impurity elements containing the elements that form precipitates combining with O, N or C; and

the total content of the precipitate forming elements is 2.5 mass % or less.

39. An iron-base amorphous alloy thin strip according to claim 37 or 38, characterized in that:

Al and/or Ti are contained in said thin strip as said precipitate forming elements; and

the contents thereof are in the ranges from 0.01 to 1 mass % as to Al and from 0.01 to 1.5 mass % as to Ti.

40. An iron-base amorphous alloy thin strip according to claim 37 or 39, characterized in that the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe, from more than 5 to 16% as to B, from 0.02 to 8% as to C, and from 0.2 to 12% in total as to one or more of P, As, Bi, S, Se and Te.

42. An iron-base amorphous alloy thin strip according to any one of claims 37 to 41, characterized in that the content of Al is in the range from 0.01 to 0.2 mass %.

43. An iron-base amorphous alloy thin strip according to any one of claims 37 to 42, characterized in that the content of Ti is in the range from 0.01 to 0.4 mass %.

44. An iron-base amorphous alloy thin strip according to any one of claims 37 to 43, characterized in that the total content of one or more of P, As, Bi, S, Se and Te is in the range from 1 to 12 atomic %.

38. An iron-base amorphous alloy thin strip characterized in that:

the composition of said thin strip consists of the main elements of Fe, Si, B, C and one or more of P, As, Bi, S, Se and Te, and impurity elements containing the elements that form precipitates combining with O, N or C; and

the total content of the precipitate forming elements is 2.5 mass % or less.

41. An iron-base amorphous alloy thin strip according to claim 38 or 39, characterized in that the contents of said main elements are, in atomic percentage, in the ranges from 78 to 86% as to Fe, from 0.02 to less than 4% as to Si, from more than 5 to 16% as to B, from 0.02 to 8% as to C, and from 0.2 to 12% in total as to one or more of P, As, Bi, S, Se and Te.

47. An iron-base mother alloy for producing a rapidly cooled and solidified thin strip, characterized by containing alloying elements of, in atomic percentage, Fe in the range from 77 to 86%, Si in the range from 1.5 to 4.5%, B in the range from 5 to 19%, C in the range from 0.02 to 4%, and P in the range from 0.2 to 16%, and the balance consisting of unavoidable impurities.

54. An inexpensive iron-base mother alloy for producing a rapidly cooled and solidified thin strip according to any one of claims 47 to 53, characterized in that:

Al and/or Ti are contained in said mother alloy; and

the contents thereof are in the ranges from 0.01 to 1 mass % as to Al and from 0.01 to 1.5 mass % as to Ti.

48. An iron-base mother alloy for producing a rapidly cooled and solidified thin strip, characterized by containing alloying elements of, in atomic percentage, Fe in the range from 78 to 86%, Si in the range from 2 to less than 4%, B in the range from 2 to 15%, C in the range from 0.02 to 4%, and P in the range from 1 to 14%, while the content of B+P is maintained in the range from 12 to 20%, and the balance consisting of unavoidable impurities.

49. An iron-base mother alloy for producing a rapidly cooled and solidified thin strip, characterized by containing alloying elements of, in atomic percentage, Fe in the range from 78 to 86%, B in the range from more than 5 to 16%, C in the range from 0.02 to 8%, and P in the range from 0.2 to 12%, and the balance consisting of unavoidable impurities.

50. An iron-base mother alloy for producing a rapidly cooled and solidified thin strip, characterized by containing alloying elements of, in atomic percentage, Fe in the range from 78 to 86%, Si in the range from 0.02 to less than 2%, B in the range from more than 5 to 16%, C in the range from 0.02 to 8%, and P in the range from 0.2 to 12%, and the balance consisting of unavoidable impurities.

51. An iron-base mother alloy for producing a rapidly cooled and solidified thin strip, characterized by containing alloying elements of, in atomic percentage, Fe_1-XCo_X (wherein 0.05≦

X≦

0.4) in the range from 78 to 86%, Si in the range from 2 to less than 4%, B in the range from more than 5 to 16%, C in the range from 0.02 to 4%, and P in the range from 0.2 to 12%, and the balance consisting of unavoidable impurities.

52. An iron-base mother alloy for producing a rapidly cooled and solidified thin strip, characterized by containing alloying elements of, in atomic percentage, Fe_1-YNi_Y (wherein 0.05≦

Y≦

0.2) in the range from 78 to 86%, Si in the range from 2 to less than 4%, B in the range from more than 5 to 16%, C in the range from 0.02 to 4%, and P in the range from 0.2 to 12%, and the balance consisting of unavoidable impurities.

53. An iron-base mother alloy for producing a rapidly cooled and solidified thin strip, characterized by containing alloying elements of, in atomic percentage, Fe in the range from 78 to 86%, Si in the range from 2 to less than 4%, B in the range from more than 5 to 16%, C in the range from 0.02 to 4%, and M in the range from 0.2 to 12%, wherein M indicates one or more of As, Bi, S, Se and Te, and the balance consisting of unavoidable impurities.