JPH06279901A - Fe-ni magnetic alloy excellent in hot workability and magnetic property - Google Patents

Abstract

PURPOSE:To improve hot workability and magnetic properties by compositely adding specific amounts of B and Mo to an Fe-Ni magnetic alloy, controlling respective contents of Pb, Bi, Sn, Zn, and S, and specifying the value of CV. CONSTITUTION:This Fe-Ni magnetic alloy has a composition consisting of, by weight, 75-85% Ni, <=0.03% C, 0.05-1.0% Si, <=2.0% Mn, <=0.05% Ti, <=0.05% Mg, <=0.05% Al, <=0.008% O, <=0.008% N, 0.0005-0.02% B, 1-10% Mo, <=15ppm Pb, <=15ppm Bi, <=200ppm Sn, <=20ppm Zn, <=50ppm S, and the balance Fe with inevitable impurities. Further, the value of CV specified by CV=Pb+ Bi+0.03Sn+0.63Zn+0.21S is regulated to <=25ppm. By this method, the Fe-Ni magnetic alloy reduced in the edge crack phenomenon occurring at the time of hot rolling and excellent in magnetic properties can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Fe-Ni-based magnetic alloy which has reduced and improved edge cracking phenomenon that occurs during hot rolling to the extent that it does not pose a problem in actual operation and has excellent magnetic properties. .

[0002]

2. Description of the Related Art Fe-Ni magnetic alloys are so-called permalloys and are widely used as soft magnetic materials for magnetic heads and magnetic shields. Sheets or foils are used for such applications and are manufactured by hot rolling a slab and then cold rolling.

However, when the Fe-Ni magnetic alloy is hot-rolled, the hot workability is poor and ear cracking may occur. If the hot-rolled alloy sheet and the strip have edge cracks, the sheet is broken during cold rolling in the subsequent process, and therefore it is necessary to perform trimming before cold rolling. This causes a significant decrease in yield.

In the conventional manufacturing, scrap is used as a raw material. In recent years, a large amount of low-priced scrap tends to be used for the purpose of reducing the manufacturing cost.
In this case, it is necessary to consider the influence of the impurity elements present in the scrap on the material properties. It has been said that cracks occur during hot workability when the concentration of impurity elements such as Pb, Bi, Sn, Zn, and S in steel increases. However, at present, the effects of these elements on the product properties have not been quantified.

Conventionally, a method of adding elements such as Mn, Ti, and Mg has been known in order to prevent the ear cracking phenomenon and improve the hot workability. However, while excessive addition of Mn, Ti, Mg, etc. deteriorates the magnetic properties, a white turbid phenomenon occurs on the surface during the final step of magnetic annealing, which impairs the design of the product, which is a problem.

From the standpoint of magnetic properties, higher magnetic properties are required as the operating frequency range of magnetic heads, magnetic shield materials, etc. increases. Therefore, there is a strong demand for an Fe—Ni-based magnetic alloy that is free from edge cracking that occurs during hot rolling and that has excellent hot workability and magnetic properties.

[0007]

SUMMARY OF THE INVENTION The present invention reduces and improves the edge cracking phenomenon that occurs during hot rolling as described above to the extent that it does not pose a problem in actual operation, and is also excellent in magnetic characteristics. An object of the present invention is to provide a magnetic alloy.

[0008]

In the present invention, B and Mo or B, Mo and Cu are added in combination for this purpose, and Pb, Bi, Sn and Z which affect hot workability are added.
As a result of detailed investigation of the influence of impurity elements such as n and S, and various investigations on other components, it was achieved by limiting the components as described below.

That is, the gist of the present invention is: (1)% by weight, Ni: 75 to 85%, C: 0.03%
Hereinafter, Si: 0.05 to 1.0%, Mn: 2.0%
Below, Ti: 0.05% or less, Mg: 0.05
% Or less, Al: 0.05% or less, O 2: 0.0
08% or less, N: 0.008% or less, B:
0.0005 to 0.02%, Mo: 1 to 10%, and the content of Pb, Bi, Sn, Zn, S is ppm by weight.
Pb: 15 ppm or less, Bi: 15 ppm or less, Sn: 200 ppm or less, Zn: 20 ppm or less, S: 50 ppm or less, and the CV value defined by the following formula (1) is 25 ppm or less, and the balance is Fe. And an inevitable impurity, which is excellent in hot workability and magnetic properties. CV = Pb + Bi + 0.03Sn + 0.63Zn + 0.21S (1) (2)% by weight, Ni: 75 to 85%, C
: 0.03% or less, Si: 0.05 to 1.0%,
Mn: 2.0% or less, Ti: 0.05% or less,
Mg: 0.05% or less, Al: 0.05% or less,
O: 0.008% or less, N: 0.008% or less,
B: 0.0005 to 0.02%, Mo: 1 to 1
0%, Cu: 1 to 10%, Pb,
The content of Bi, Sn, Zn, S is ppm by weight, and Pb:
15ppm or less, Bi: 15ppm or less, Sn:
200 ppm or less, Zn: 20 ppm or less, S:
CV less than 50ppm and defined by the following formula (1)
Value of 25 ppm or less, the balance being Fe and inevitable impurities, and an Fe-Ni-based magnetic alloy excellent in hot workability and magnetic properties. CV = Pb + Bi + 0.03Sn + 0.63Zn + 0.21S ... (1)

The reasons for limiting the chemical composition of the alloy of the present invention will be described in detail below. Ni is a basic component of the present alloy, and when Ni is less than 75% or more than 85%, the magnetic properties of the alloy are deteriorated and the properties as a soft magnetic material cannot be exhibited. Therefore, the range of Ni is 75-
It was set to 85%. If the content of C is too large, it forms carbides in the alloy and deteriorates hot workability and magnetic properties, so the upper limit was made 0.03%. Si is an effective component as a deoxidizing agent, and if it is less than 0.05%, its effect is small, and if it exceeds 1.0%, SiO ₂ is remarkably generated and the magnetic properties are deteriorated. Therefore, the range of Si is set to 0.05 to 10%. More preferably,
0.20 to 0.50% is good. When Mn exceeds 2.0%, the upper limit of 2.0 is set in order to saturate the hot workability.
%.

Ti is an effective component for improving hot workability and as a deoxidizing agent, but if it exceeds 0.05%, TiO ₂ segregates on the product surface after magnetic annealing to cause a clouding phenomenon. Was set to 0.05%. More preferably,
0.03% or less is good. Mg is an effective component for improving hot workability, but if it exceeds 0.05%, MgO segregates on the product surface after magnetic annealing to cause a clouding phenomenon, so the upper limit is made 0.05%. did. More preferably,
0.03% or less is good. Al is an effective component as a deoxidizing agent, but if it exceeds 0.05%, Al ₂ after magnetic annealing
O ₃ is concentrated on the surface of the product and causes a white turbidity phenomenon, so the upper limit was made 0.05%. More preferably, it is 0.03% or less. If the content of O is too large, an oxide precipitates and deteriorates the magnetic properties, so the upper limit is 0.008.
%. More preferably, it is 0.003% or less.

If the content of N is too large, nitride precipitates and deteriorates the magnetic properties, so the upper limit is 0.00.
8%. More preferably, it is 0.003% or less.

B is an effective component for preventing grain boundary segregation of S and improving hot workability and magnetic properties.
If it is less than 05%, its effect is small, and if it exceeds 0.02%, a hard and brittle boride is formed, and hot workability and magnetic properties are deteriorated. Therefore, the range of B is 0.00
It was set to 05% to 0.02%. Mo and Cu are effective elements for improving the magnetic properties due to the combined effect of B in the above component range. Mo is effective when added in an amount of 1% or more alone, and is effective in magnetic properties when Mo and Cu are combined and added in an amount of 1% or more. However, if these elements are added in an amount of more than 10%, on the contrary, the magnetic characteristics, especially the saturation magnetic flux density, become small. Therefore, when improving the magnetic properties, Mo is added in an amount of 1 to 10% alone, or Mo and Cu are added in a combined amount of 1 to 10%.

Pb, Zn and Bi are liable to segregate due to the solute concentration during solidification and easily form a low melting point phase at the grain boundary, so that the hot workability is remarkably reduced. Therefore, Pb,
The upper limit of Bi was 15 ppm and the upper limit of Zn was 20 ppm.
Although Sn and S have less influence than Pb, Zn, and Bi, they tend to deteriorate hot workability at high concentrations, so the upper limits were set to 200 ppm and 50 ppm, respectively. As described above, these impurity elements are likely to segregate due to the solute concentration during solidification and to form a low melting point phase at grain boundaries. The coefficient of each element in the above formula (1) is determined by two factors: segregation and low melting point phase forming ability. The CV value is an index showing the influence of the content of the impurity element on the hot workability. Pb, Bi, Sn, Zn
S and S are mixed from scrap and alloy raw materials. Pb, Bi, and Zn are high vapor pressure components and can be removed by an evaporation reaction under high temperature by controlling the refining time. On the other hand, Sn has a lower vapor pressure than Pb, Bi, and Zn, and thus is difficult to remove even by an evaporation reaction,
In the current mass production process, there is no choice but to select raw materials. On the other hand, S can be removed by slag refining, and for example, desulfurization treatment using high basicity slag is performed. In the present invention, by utilizing the raw material selection, the evaporation reaction, and the slag refining, C
By controlling the value of V to be 25 ppm or less, it is possible to stably obtain a material having excellent hot workability. FIG. 1 shows the relationship between the drawing value at the time of hot tensile rupture, the surface flaw generation rank of the hot rolled sheet, and the CV value. CV
When the value of was more than 25 ppm, the hot workability was remarkably deteriorated, and flaws were observed on the surface and the edges during hot rolling.
Therefore, the value of CV is limited to 25 ppm or less. Further, the higher the drawing value is, the better the hot workability is. In the present invention, if it is about 80% or more, hot rolling can be performed without generating defects such as cracks.

[0015]

EXAMPLES Next, the superiority of the present invention will be specifically described with reference to Examples and Comparative Examples. Table 1 shows the chemical components, hot workability, and magnetic properties of the inventive example and the comparative example.

The alloy of the present invention and the comparative alloy as shown in Table 1 were melted in a vacuum induction melting furnace and made into a slab by a continuous casting method. Then, after heating at 1250 ° C. for 2 hours, hot rolling was performed. Moreover, evaluation of each characteristic was performed by the following method. (1) Hot workability A high-speed tensile test was performed in the cooling process after heating at 1250 ° C. The hot workability was evaluated by the hot drawing value (%) of the tensile fracture portion at 1100 ° C in the cooling process. Further, hot rolling was performed, and the surface flaws and the occurrence of edge cracks of the hot rolled sheet at that time were ranked as follows. ○: No surface flaws and edge cracks occurred △: Partial surface flaws and edge cracks occurred ×: Full surface flaws and edge cracks occurred (2) Magnetic characteristics Slits on the edges of the hot-rolled sheet were used to remove surface flaws, and cold After rolling and intermediate annealing were repeated to obtain a cold-rolled thin plate having a plate thickness of 0.5 mm, a ring piece having an outer diameter of 45 mm and an inner diameter of 33 mm based on the JIS standard was sampled. Then, magnetic annealing (1100 ° C x 3
The maximum relative magnetic permeability was measured by performing dew point: -45 ° C) in a hydrogen atmosphere for a period of time.

[0017]

[Table 1]

[0018]

[Table 2]

Inventive Example No. 1 to 7 and Comparative Example No. 8 to 1
9 is a constituent element, an impurity element Pb, Bi, Sn, Zn,
It shows the influence of the S amount and the CV value. When the amount of each element or the CV value exceeds the range of the present invention, the hot workability is inferior to that of the present invention.

Comparative Example No. No. 12 has a Pb amount of No. No. 13 has a Bi content of No. No. 14 has a Sn content of No. No. 15 has a Zn content of No. No. 16 has a high S content and exceeds the range of the present invention for the CV value singly, the hot workability is poor, and cracks occur during hot rolling. In addition, Comparative Example No. 17 is Pb,
Bi is No. No. 18 had high Sn and Zn and had a CV value exceeding the range of the present invention. In this case as well, the hot workability was remarkably inferior and cracks frequently occurred during hot rolling.
In addition, Comparative Example No. 19 is an impurity element Pb, Bi, S
Although the amounts of n, Zn and S are within the range of the present invention, the CV value exceeds the range of the present invention, and in this case as well, the hot workability is remarkably inferior and cracks frequently occur during hot rolling. On the other hand, Comparative Example No. Nos. 8 and 9 have a Ni content of No. 10 is M
o is No. No. 11 has Mo and Cu exceeding the range of the present invention, and in this case, the magnetic characteristics are remarkably deteriorated.

[0021]

As is apparent from the above, the Fe-Ni-based magnetic alloy according to the present invention reduces and improves the ear cracking phenomenon that occurs during hot rolling to such an extent that it does not pose a problem in actual operation, and has magnetic characteristics. It is also excellent.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a drawing value at the time of hot tensile rupture, a surface flaw of a hot-rolled sheet, and a crack generation rank of an edge crack, and a CV value.

Claims (2)

[Claims] 1. By weight%, Ni: 75 to 85%, C: 0.03% or less, Si: 0.05 to 1.0%, Mn: 2.0% or less, Ti: 0.05% Hereinafter, Mg: 0.05% or less, Al: 0.05% or less, O: 0.008% or less, N: 0.008% or less, B: 0.0005 to 0.02%, Mo: 1 to 10 %, And the content of Pb, Bi, Sn, Zn, S is ppm by weight, Pb: 15 ppm or less, Bi: 15 ppm or less, Sn: 200 ppm or less, Zn: 20 ppm or less, S: 50 ppm or less, and The value of CV defined by the following formula (1) is 25pp
F having excellent hot workability and magnetic properties, characterized in that the content is m or less and the balance is Fe and inevitable impurities.
e-Ni magnetic alloy. CV = Pb + Bi + 0.03Sn + 0.63Zn + 0.21S ... (1) 2. In% by weight, Ni: 75 to 85%, C: 0.03% or less, Si: 0.05 to 1.0%, Mn: 2.0% or less, Ti: 0.05% Hereinafter, Mg: 0.05% or less, Al: 0.05% or less, O: 0.008% or less, N: 0.008% or less, B: 0.0005 to 0.02%, Mo: 1 to 10 %, Cu: 1 to 10%, and the content of Pb, Bi, Sn, Zn, S is ppm by weight, Pb: 15 ppm or less, Bi: 15 ppm or less, Sn: 200 ppm or less, Zn: 20 ppm or less, S: : 50 ppm or less and CV value defined by the following formula (1) is 25 pp
F having excellent hot workability and magnetic properties, characterized in that the content is m or less and the balance is Fe and inevitable impurities.
e-Ni magnetic alloy. CV = Pb + Bi + 0.03Sn + 0.63Zn + 0.21S ... (1)