JPH11343544A - Iron-chromium-silicon alloy excellent in high frequency magnetic property and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an Fe-Cr-Si alloy having good magnetic properties as well as excellent workability at the time of producing and moreover combining corrosion resistance and inexpensiveness. SOLUTION: This alloy is the one having a compsn. contg., by weight, 1.5 to 20% Cr, 2.5 to 10% Si and <=5% Al, in which the total content of C and N is reduced to <=100 ppm, and the balance iron with inevitable impurities and having >=60 μΩcm specific resistance. One or more kinds selected from Mn, P and Al may be incorporated therein respectively by <=1%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to Fe-Cr-Si alloys having excellent magnetic properties, and more particularly to Fe-Cr-Si alloys having good magnetic properties when used as electrical steel sheets at frequencies higher than the commercial frequency. The present invention relates to a system alloy and a method for producing the same.

[0002]

2. Description of the Related Art An Fe-Si alloy is known as a material having excellent soft magnetic properties, and is frequently used mainly as an electromagnetic steel sheet having a Si content of 3.5 wt% or less, mainly for various commercial frequency iron cores. However, when the operating frequency is higher than the commercial frequency, there is a disadvantage that the iron loss is increased in the magnetic steel sheet having the Si content of 3.5 wt% or less. Therefore, in order to improve the iron loss characteristics in a frequency range higher than the commercial frequency, a material having higher electric resistance is required.

[0003] Here, if the amount of Si in the steel is increased, the electric resistance increases, which is advantageous in reducing the iron loss in the high frequency range as described above. However, on the other hand, when the amount of Si is 3.5
If the content exceeds wt%, the alloy becomes extremely hard and brittle, resulting in poor workability, which makes it difficult to manufacture and process by rolling.
In particular, when the Si content exceeds 5.0 wt%, not only cold working but also warm working becomes impossible.

A technique for improving the workability of this high Si steel and industrially producing a steel sheet even when containing about 6.5 wt% of Si is disclosed in JP-A-61-166923. A method by hot rolling under high pressure.
A method based on the diffusion and infiltration treatment of Si disclosed in Japanese Patent No. 7078 is representative.

[0005]

However, the former technique disclosed in Japanese Patent Application Laid-Open No. Sho 61-166923 requires fine adjustment of the rolling structure to apparently improve the brittleness of the alloy. Strict control in the process,
It is presumed that industrially stable production is difficult. On the other hand, in the latter technique disclosed in Japanese Patent Application Laid-Open No. 62-227078, a special diffusion infiltration method is used, so that it is considered to be extremely disadvantageous in terms of cost when performing industrial production. In addition, although there is a limit to further increasing the electric resistance in order to obtain good high-frequency magnetic characteristics, even if the amount of Si is increased by these methods, it must be at most 80 μΩcm. In particular, when the amount of Si was 3.5 wt% or less, which can be produced by a normal industrial rolling method, a specific resistance of only about 50 μΩcm was obtained. Also, these Fe-Si alloys
Poor corrosion resistance is also a problem in applications such as iron cores.

On the other hand, Al has the effect of increasing the electric resistance in the same manner as Si from the viewpoint of magnetic properties, and does not deteriorate workability as much as Si. Therefore, it is known that workability is improved by substituting a part of Si with Al. Al
Although it is more expensive than Si and has weaknesses such as a large decrease in magnetic flux density, for example, steel with a composition of Si: 3 wt% and Al: 0.7 wt% is processed more than steel with a composition of Si: 3.7 wt%. , Cold-rolling properties and magnetic properties are almost the same. However, when the total amount of Si and Al is 4 wt% or more in steel with Si: 3 wt% or more, cold rolling becomes impossible,
If the total amount of Al and Al exceeds 6 wt%, warm rolling has also become difficult. In this case as well, after all, industrially 60μΩ
Only a specific resistance of less than cm was obtained.

In any case, rather than simply reducing the iron loss in the high frequency range by simply increasing the amount of Si or Al, the new component-based alloy with essentially improved workability, together with the magnetic properties over the high frequency range, It is also desirable to ensure good corrosion resistance and to satisfy corrosion resistance and low cost.

As a means for improving the corrosion resistance of an Fe—Si alloy, a method of adding a certain amount of Cr is disclosed in Japanese Patent Laid-Open No. 52-24 / 1982.
No. 117 and JP-A-61-27352. As described above, alloys having improved corrosion resistance by adding Cr are known. However, all of the alloys disclosed in these publications have the same magnetic properties as conventional alloys and have not been significantly improved.

Therefore, the present invention solves the above-mentioned problems, and has not only excellent workability at the time of manufacture and use, but also high electrical resistance and good high-frequency magnetic characteristics, and also has corrosion resistance and low cost. It is intended to propose an Fe-Cr-Si based alloy. If the workability at the time of manufacturing is improved in this way, it becomes possible to make the steel sheet particularly thin, and the high-frequency magnetic characteristics are further improved.

[0010]

Means for Solving the Problems The inventors have conducted intensive studies to achieve the above object, and as a result, obtained the following new findings. First, regarding the securing of workability (which can be almost evaluated by toughness), Fe-Si alloys and Fe-Si-Al
It was surprisingly found that coexistence of Cr is effective for improving the toughness of the alloy. That is, until now
It has been thought that the more Cr is added, the more the toughness deteriorates.
Even if the content of Si is 3 wt% or more and the content of Al is 1 wt% or more, high toughness can be obtained by sufficiently reducing the C + N content and by adding a certain amount of Cr or more. Was found to be able to. Moreover, the amount of Si and the amount of Al are even lower.
Fe-Cr-Si alloys (Fe-Cr-Si- alloys in addition to Fe-Cr-Si alloys)
Also includes Al alloy. same as below. ) And the specific resistance is 60μΩ
cm or more, if the content of C + N is sufficiently reduced, an Fe-Si alloy or Fe-Si alloy having the same specific resistance can be obtained.
-It was found that the workability was significantly improved compared to the -Al alloy.

The magnetic properties of Cr, Si and Al
Was found to have a synergistic effect on the increase in electrical resistance. As a result, especially iron loss in the high frequency range, Fe-Si alloy containing only Si and Al,
Fe-Al alloys, and further reduced significantly compared to Fe-Si-Al alloys. Moreover, if Cr is added in this manner, the corrosion resistance is reduced by the effect of the conventional Fe-Si.
It definitely improves compared to the system.

The present invention is based on the above findings, and the gist configuration thereof is as follows. Cr: 1.5 wt% or more and 20 wt% or less and Si: 2.5 wt% or more and 10 wt% or less, and C and N are reduced to 100 wtppm or less in total, and the balance consists of iron and unavoidable impurities. Resistance is 60
Fe-Cr-Si based alloy with excellent high frequency magnetic properties characterized by being at least μΩcm. Cr: 1.5 wt% or more and 20 wt% or less,
Si: 2.5 wt% or more and 10 wt% or less and Al: 5 wt% or less, and the total amount of C and N is reduced to 100 wtppm or less, and the balance is composed of iron and unavoidable impurities.
Fe-Cr-Si based alloy with excellent high frequency magnetic properties characterized by being at least μΩcm. Cr: 1.5 wt% or more and 20 wt% or less and Si: 2.5 wt% or more and 10 wt% or less, each containing 1 or 2 kinds selected from Mn and P within 1 wt%, and the total of C and N Fe- is excellent in high-frequency magnetic characteristics characterized in that it is reduced to 100 wtppm or less, the balance being iron and unavoidable impurities, and having a specific resistance of 60 μΩcm or more.
Cr-Si alloy. Cr: 1.5 wt% or more and 20 wt% or less, Si: 2.5
1 wt% or less and 10 wt% or less and Al: 5 wt% or less, each containing 1 or 2 kinds selected from Mn and P within 1 wt%, and the total amount of C and N to 100 wtppm or less. Reduced, with the balance being iron and unavoidable impurities, with a resistivity of 60
Fe-Cr-Si based alloy with excellent high frequency magnetic properties characterized by being at least μΩcm. In the Fe-Cr-Si alloy excellent in high-frequency magnetic characteristics of the present invention, the plate thickness is 0.01 to 0.4 mm.
Is more preferable. Cr: 1.5 wt% or more and 20 wt%
Or less and Si: not less than 2.5 wt% and not more than 10 wt%, and C
Fe-Cr-Si in which the total amount of N and N is reduced to 100 wtppm or less
When rolling the base alloy material, hot rolling
mm or less, and then hot-rolled sheet is rolled cold or warm without annealing, and a method for producing an Fe-Cr-Si alloy having excellent high-frequency magnetic properties. Cr: 1.5 wt% or more and 20 wt%
% And Si: not less than 2.5 wt% and not more than 10 wt%, and
Fe-Cr- in which C and N are reduced to 100 wtppm or less in total
When rolling a Si-based alloy material, a Fe-Cr-Si-based alloy excellent in high-frequency magnetic characteristics, characterized in that cold rolling or warm rolling after hot rolling is performed without performing intermediate annealing. Production method. Cr: 1.5 wt% or more and 20 wt% or less and Si: 2.
When rolling a Fe-Cr-Si based alloy material containing 5 wt% or more and 10 wt% or less and having a total amount of C and N reduced to 100 wtppm or less, the thickness is reduced to 3 mm or less by hot rolling. The hot-rolled sheet is subjected to cold rolling or warm rolling without annealing, and the cold or warm rolling is performed without intermediate annealing.
Manufacturing method of Fe-Cr-Si alloy. In the method for producing an Fe-Cr-Si-based alloy having excellent high-frequency magnetic properties according to the present invention,
-The Cr-Si based alloy material contains 5 wt% or less of Al, and the Fe-Cr-Si based alloy material contains one or two selected from Mn and P within 1 wt% each. Those can also be used.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the results of experiments which have led to the present invention will be described. Fe with a purity of 99.99% or more,
Using Cr, Si, and Al as raw materials, high-purity Fe- (0 to 12) wt% Cr-4.5 wt% Si in a small melting furnace with high vacuum (1 × 10 ^-4 Torr)
-2 wt% Al alloy, Cr content 0 wt%, 2 wt%, 4 wt%
10 kg each was melted as a component composition to be wt% and 12 wt%. The obtained alloy has an impurity content of C: 5 to 8 wtppm.
, P: 3-5 wtppm, S: 2-3 wtppm, N: 12-18 w
tppm, O: 11 to 15 wtppm, and C + N: 18 to 22 wtppm. These ingots were cut to a thickness of 60 mm, heated to 1100 ° C., and rolled to a plate thickness of 3.2 mm. From this steel plate, 2.
5 mm, width 10 mm, length 55 mm, notch 2 mm V-notch Charpy test specimens were taken in parallel with the rolling direction, the impact value was measured at each temperature, the temperature at which the brittle fracture rate was 50%, The ductility-brittle transition temperature was determined as an index of toughness. Each composition with different Cr content (Fe-Xwt% Cr-4.5wt% Si-2wt% Al)
Table 1 shows the relationship of the transition temperature with respect to.

[0014]

[Table 1]

Unexpectedly, it was found that the transition temperature decreased with an increase in the Cr content, that is, the toughness was improved, and that the effect was exhibited when the Cr content was 2 wt% or more.
It was found that the effect was saturated even if the amount was increased beyond 20 wt%. If the transition temperature is 200 ° C. or lower, ordinary warm rolling at about 300 ° C. can be performed. If the transition temperature is 100 ° C or less, the material can be manufactured by first heating the material to 200 ° C or less and then subjecting the material to a cold rolling process in the same manner as ordinary cold rolling. Is more advantageous. Next, regarding the composition of Fe-4 wt% Cr-4.5 wt% Si-2 wt% Al, the same as above except that a Fe-5 wt% C master alloy and iron nitride were added to adjust C and N. In the method of C
Alloys having different + N contents were produced, and the Charpy test was performed in the same manner. The results shown in Table 2 were obtained.

[0016]

[Table 2]

As described above, it has been found that when C + N is less than about 100 wtppm, the toughness is remarkably improved. In this case, normal warm rolling can be performed.

Further, among these hot rolled sheets, the C + N amount is
For the 19wtppm Fe-4wt% Cr-4.5wt% Si-2wt% Al alloy and the comparative material Fe-6wt% Si (C + N is 19wtppm) alloy, a 0.2mm thick sheet was made by warm rolling. 1200 in hydrogen
After annealing at 60 ° C. for 60 minutes, the specific resistance and magnetic properties were measured. Here, the Fe-4 wt% Cr-4.5 wt% Si-2 wt% Al alloy was warm-rolled by heating the hot-rolled sheet to 300 ° C.
Since the% Si alloy was extremely brittle and ordinary warm rolling was impossible, the heating of the hot-rolled sheet was particularly set at 450 ° C., and the sheet was reheated for each rolling pass to make a thin sheet. The specific resistance of each alloy is Fe-4 wt
% Cr-4.5 wt% Si-2 wt% Al alloy is 120 μΩcm,
It greatly exceeded the value of 81 μΩcm of Fe-6 wt% Si. Also frequency
The iron loss value at 10 kHz and a magnetic flux density of 0.1 T was investigated. The results show that the Fe-4% Cr-4.5 wt% Si-2 wt% Al alloy was 15 W / k
g, Fe-6wt% Si alloy was 18W / kg, and the former was much better.

The present invention has been obtained based on the above experimental facts as a starting point of development, and the selection of the component system and the purity plays an important role. The reasons for limiting the numerical ranges of these component composition ranges will be described below.

First, Cr is a basic alloying component that greatly improves electrical resistance by a synergistic effect with Si and Al, reduces iron loss in a high frequency range, and further improves corrosion resistance. 3.5 wt% or more Si content, or 3 wt%
Even if the Si content is more than 1% and the Al content is more than 1%, it is extremely effective for obtaining toughness to the extent that it can be warm-rolled. From that viewpoint, 2 wt% or more is required. Si amount and Al
When the amount is smaller than the above case, the workability can be ensured even if the Cr amount is further reduced.However, in order to exhibit the effect of improving the workability of Cr, and to make the specific resistance of the alloy 60 μΩcm or more, 1.5 Cr of at least wt% is essential. On the other hand, if the content exceeds 20 wt%, the effect of improving toughness is saturated and the cost is increased. Therefore, the content of Cr is 1.5 wt% or more and 20 wt% or less,
Preferably 12 wt% or more, 10 wt% or less, more preferably,
Defined as 3 wt% or more and 7 wt% or less.

[0021] Si is a component effective for greatly increasing electric resistance by a synergistic effect with Cr and reducing iron loss in a high frequency range. If the amount of Si is less than 2.5 wt%, even if Cr and Al are used together, a specific resistance of 60 μΩcm or more cannot be obtained without sacrificing much the magnetic flux density. On the other hand, if the content exceeds 10 wt%, the toughness until warm rolling cannot be ensured even if Cr is contained. Therefore, the content of Si is 2.5 wt% or more and 10 wt% or less, preferably 3 wt% or more and 7 wt%. Hereinafter, it is more preferably defined as 3.5 wt% or more and 5 wt% or less.

Al, like Si, is a component that is effective in significantly improving electrical resistance by a synergistic effect with Cr and reducing iron loss in a high-frequency range. Can be contained. However, when the amount of Al is 5 wt%
Exceeding the cost will lead to an increase in cost, as well as Si
When the content is 2.5 wt% or more, the toughness until warm rolling can not be ensured even if Cr is added, so the Al content is 5 wt% or less. The lower limit of Al does not need to be particularly limited, but is preferably 0.005 to improve deoxidation and grain growth.
About 0.3 wt% may be contained. Further, when Al is positively used for increasing the electric resistance, an alloy containing 2.5 wt% or more of Si as in the present invention is used.
If Al is less than 0.5 wt%, a sufficient effect for further increasing the electric resistance cannot be obtained. Therefore, the content of Al is preferably not less than 0.005 wt% and not more than 5 wt%, more preferably
It is specified as 0.5 wt% or more and 3 wt% or less.

C and N are preferably reduced as much as possible in order to degrade the toughness of the Fe—Cr—Si alloy, and the allowable amounts thereof are as follows in the case of the Cr amount, Si amount and Al amount according to the present invention. In order to ensure high toughness, it is necessary to suppress the total amount to 100 wtppm or less. Preferably not more than 60 wtppm, more preferably
It is 30wtppm or less. Note that each of C and N has a C of 30.
The content of N is preferably not more than 80 wtppm, more preferably not more than 10 wtppm of C and not more than 20 wtppm of N. Also,
Although the amount of impurities other than C and N is not particularly limited, S: 20 wt.
ppm or less, preferably 10 wtppm or less, more preferably 5 ppm or less.
It is better to be less than wtppm. O: 50 wtppm or less, preferably 30 wtppm
ppm or less, more preferably 15 wtppm or less. Or
The total amount of impurities C + S + N + O is preferably 120 wtppm or less, more preferably 50 wtppm or less.

It is known that Mn and P further increase the electric resistance by being further added to the Fe-Cr-Si alloy. By the addition of these components, a further reduction in iron loss can be achieved without impairing the spirit of the present invention. Therefore, in the present invention, one or two selected from Mn and P can be contained. Nevertheless, adding large amounts of these components will increase costs,
The upper limit of each addition amount is 1 wt%. More preferably, it is 0.5 wt% or less.

In the present invention, the magnetic characteristics,
The addition of conventionally known alloy components for the purpose of further improving corrosion resistance, workability, and the like does not impair the effects of the present invention, and it is possible to include those components. Representative examples of those components are listed below. Ni of 5 wt% or less is a component that improves corrosion resistance, lowers the ductile-brittle transition temperature, improves workability, and suppresses eddy current loss because crystal grains are easily made finer.
It is also effective in reducing high frequency iron loss. For less than 1 wt% Cu
It has the same effect as Ni. Mo or W of 5 wt% or less improves corrosion resistance. La, V or Nb of 1 wt% or less, T of 0.1 wt% or less
i, Y, Zr, and B of 0.1 wt% or less have the effect of increasing toughness and improving workability. Co of 5 wt% or less improves the magnetic flux density and is effective in reducing iron loss. 0.1 wt%
The following Sb and Sn improve the texture and are effective in reducing iron loss.

The high workability Fe- excellent in the magnetic material of the present invention.
In order to produce Cr-Si alloy thin plates, the purity must be 99.9%.
High purity electrolytic iron, electrolytic chromium, metallic Si, metal with wt% or more
It is preferable to use Al. When Mn and P are added, they also use high-purity raw materials. Alternatively, in the case of manufacturing by the converter method, care must be taken to sufficiently refine to a predetermined purity and not to be contaminated in a later step. At the time of melting, besides the converter method, for example, high vacuum (10
A vacuum melting furnace having a pressure of ^-3 Torr or less can be used.

In the subsequent hot rolling, by rolling as thin as possible, the workability in the next step of cold rolling or warm rolling, ie, the rolling property, can be improved. This is based on the new finding that in the case of the Fe-Cr-Si-based alloy composition of the present invention, the surface portion of the hot-rolled sheet has higher toughness than the central portion and has excellent workability. is there. The thickness of the hot rolled sheet for that purpose is 3 mm or less, preferably 2.
5 mm or less, more preferably 1.5 mm or less.

Since the toughness of the hot-rolled sheet is improved, the sheet can be further rolled hot or cold to form a thin sheet having a thickness of 0.4 mm or less. In general, it is well known that reducing the plate thickness advantageously suppresses eddy current loss, especially at high frequencies, and reduces iron loss. However, materials having high electric resistance have poor rollability so far, and the thickness has been reduced to only about 0.5 mm by a normal rolling method. It has also been said that simply reducing the thickness does not allow a sufficient reduction in iron loss due to hysteresis loss. In this regard, the present invention has found that the effect of the high-frequency iron loss characteristics when the thickness is reduced can be promoted by selecting the component system and the purity. In order to obtain such an effect of thickness reduction, it is effective to make the plate thickness 0.4 mm or less. However, it is industrially impossible to reduce the thickness to less than 0.01 mm.
mm, preferably 0.03 to 0.35 mm.

In such rolling for thickness reduction,
Because the workability of the material is excellent, it is not always necessary to secure the rollability by annealing the hot-rolled sheet as in the past, or intermediate annealing during cold rolling or warm rolling, especially in the past. , Improving work efficiency by omitting hot-rolled sheet annealing and intermediate annealing,
Energy saving and cost reduction can be achieved. Subsequent annealing and surface finishing can be performed by the same steps as those for a normal electromagnetic steel sheet or an electromagnetic stainless steel sheet.

[0030]

EXAMPLES (Example 1) Electrolytic iron and electrolytic chromium having a purity of 99.99 wt%, metal Si having a purity of 99.999 wt%, and metal aluminum having a purity of 99.99 wt% and, if necessary, 99.9 wt%
Metal manganese, Fe-23wt% P master alloy with 99.5wt% purity as raw material, in a small melting furnace of high vacuum (1 × 10 ^-4 Torr)
Alloys having various component compositions shown in Table 3 were melted at 10 kg each. Here, when Al was not included as a main component, 0.01 wt% (1 g) of aluminum foil was degreased and added for deoxidation. These ingots were cut out to a size of 40 mm x 60 mm x 100 mm, heated to 1100 ° C in Ar and held for 30 minutes, and then roughly rolled to a shape that reduced 60 mm to 20 mm, and further 1100 ° C
After reheating for 15 minutes, hot rolling was performed to a sheet thickness of 2.3 mm.

[0031]

[Table 3]

From this steel sheet, a thickness of 1.5 mm, a width of 10 mm, and a length of
A Charpy test specimen with a notch of 2 mm V notch with a notch of 55 mm was taken in parallel with the rolling direction, and the Charpy impact value was measured at a temperature of every 25 ° C., and the temperature at which the brittle fracture ratio became 50%, that is, the ductile-tough transition Temperature was determined as an index of toughness.

Next, the surface of the previously hot-rolled 2.3 mm-thick plate was cleaned by shot blasting, and then 0.20 mm without annealing.
Cold rolling up to mm was performed. However, when the transition temperature was higher than room temperature, warm rolling was performed by preheating to 300 ° C. In particular, when the transition temperature exceeds 200 ° C., the heating temperature was set to 450 ° C., and warm rolling was performed by reheating each pass. Subsequently, from these thin plates, an outer diameter of 30 mm and an inner diameter of 20 mm
The ring-shaped test piece was cut out, annealed in hydrogen at 1000 ° C. for 60 minutes, and the iron loss value at a frequency of 10 kHz and a magnetic flux density of 0.1 T was measured by a BH analyzer. Separately, a test piece having a width of 30 mm and a length of 280 mm was cut out from the same thin plate, annealed in the same manner as described above, and the specific resistance was measured by a four-terminal method. Table 4 shows the transition temperature of each steel type, the heating method in warm rolling, the specific resistance, and the iron loss value. The corrosion resistance was evaluated by performing a salt spray test in accordance with JIS Z2371 for 2 hours.
% Was judged as "good", more than 20% and less than 80% as "medium", and more than 80% as "poor".

[0034]

[Table 4]

Steel type 1 is a conventional component system (3 wt.
% Si). Steel type 2 is a comparative example in which Cr is less than the range of the present invention, and although iron loss is reduced by increasing the amount of Si, the toughness is inferior to steel type 1 and the corrosion resistance is poor. Steel type 3
Is in the composition range of the present invention and has both high toughness, low iron loss and high corrosion resistance. Steel type 4 is an example in which Si is insufficient. The toughness is good, but the iron loss remains at the level of steel type 1. Steel type 5 is an example in which the amount of Si is further increased, but has high toughness due to high purification by reducing the amounts of C and N, and has extremely low iron loss and is excellent.

[0036] Steel types 6 and 7 are further defined as A in the present invention.
This is an example in which l, P, and Mn are additionally added, and all have high toughness and low iron loss. Steel types 8 and 9 are examples in which the amount of C + N was increased as compared with the other examples, where steel type 9 was too high beyond the scope of the present invention, and steel type 9 had deteriorated toughness and reduced iron loss. It is rising slightly.

Steel type 10 is an example in which the purity is further increased within the scope of the present invention, and shows that the toughness and the iron loss are further improved, and the magnetic material becomes an extremely excellent magnetic material. Steel type 11.
This is an example in which even if the amount is increased to 4 wt%, the toughness is ensured by increasing the amount of Cr accordingly and making it extremely high in purity. In this case, the specific resistance is high, and the iron loss is further reduced. Steel type 12 shows Fe-6.5 wt% Si, which has the lowest iron loss among binary alloys of Fe-Si, as a comparison.
This composition has extremely poor workability, but has excellent magnetic properties. On the other hand, the alloy of the present invention has significantly excellent workability, has good corrosion resistance due to the inclusion of Cr, and has an iron loss of 10%.
It has been reduced to almost the same.

Example 2 Alloys having various component compositions shown in Table 5 were melted by the same steps as in Example 1. After the smelting, a steel sheet was prepared in the same process as in Example 1 and evaluated. However, for warm rolling, after the surface of a 2.3 mm thick hot-rolled sheet is cleaned with shot blast,
Heat to 300 ° C and repeatedly reduce the thickness to 0.2mm
Warm rolling was performed until the thickness reached mm. The transition temperature is 200
When the temperature exceeds ℃, the heating temperature was set to 450 ℃, and warm rolling was performed by reheating each pass. The evaluation conditions for the toughness of the hot-rolled sheet, the magnetic properties, the electrical resistance, and the corrosion resistance of the thin sheet are the same as those in Example 1. Table 6 shows the evaluation results.

[0039]

[Table 5]

[0040]

[Table 6]

Steel type 21 was prepared using a conventional component system (6.5
wt% Si). Although this composition is extremely brittle, it is difficult to perform normal cold or warm rolling, but has good magnetic properties, especially properties at 1 kHz or higher. In the present invention, this 6.5
Workability is much better than wt% Si steel, that is, the ductile-brittle transition temperature is 200 ° C or lower, preferably 100 ° C or lower, more preferably 70 ° C or lower, and the high-frequency iron loss is 6.5 wt%. Comparing or surpassing Si steel, that is, the iron loss value under the above iron loss measurement conditions is 20
The basic principle is to be at most W / kg, preferably at most 18 W / kg. Steel type 22 is a comparative example having a shortage of Cr, has poor toughness, and has a problem in workability. Steel types 23 and 24 are in the composition range of the present invention, and have low transition temperature and toughness that enables normal warm rolling.
The iron loss is even lower than that of the% Si steel, and the iron loss is almost comparable even with steel type 24. Steel type 25 has an excessive amount of Si and steel type 26 has an excessive amount of Al, and the toughness is deteriorated.

Steel type 27 is an example in which P and Mn are further added in the present invention, and can be subjected to ordinary warm rolling and has low iron loss. Steel types 28 and 29 are examples in which the amount of C + N is increased as compared with the other examples. When steel 28 is within the scope of the present invention, steel type 29 is too high beyond the scope of the present invention. The toughness has deteriorated and the iron loss has also increased.

Steel type 30 and steel type 31 are examples in which the purity is further increased within the scope of the present invention, and the toughness and iron loss characteristics are further improved, indicating that they are extremely excellent magnetic materials. Steel type 32 is a comparative example of 3.4 wt% Si steel which is close to a normal silicon steel sheet, and has extremely high iron loss.

(Embodiment 3) This embodiment shows the effect of the thickness of a product. First, alloys having various component compositions shown in Table 7 were produced by the same steps as in Example 1. After the smelting, a steel sheet was prepared in the same process as in Example 1 and evaluated. However, for warm rolling, the surface of a 2.3 mm thick hot-rolled sheet was
C., and was repeatedly rolled down to perform warm rolling until the sheet thickness became 0.2 mm. The evaluation conditions for the magnetic properties, electric resistance, and corrosion resistance of the thin plate are the same as those in the first embodiment. Table 8 shows the evaluation results.

[0045]

[Table 7]

[0046]

[Table 8]

With the component system of the present invention (steel types 42 and 43), if the plate thickness is 0.25 mm or less, a low iron loss of 20 W / kg or less can be obtained. Steel type 41) is 0.
It is necessary to reduce the thickness to about 1 mm. Even in the case of the component system of the present invention, the plate thickness needs to be 0.4 mm or less in order to make it 20 W / kg or less.

(Embodiment 4) In this embodiment, the effect of the thickness of the hot rolled sheet is shown. The steel type was steel type 43 of Example 3 (4.1 wt% Cr
-4Z2 wt% Si-0.9 wt% Al) and melted by the same process as in Example 1. 40mm x 60mm x from the obtained ingot
Cut out 100 mm rolled material and heat it to 1100 ° C in Ar
After holding for 30 minutes, rough rolling was performed to reduce the thickness from 60 mm to 20 mm, reheating to 1100 ° C. and holding for 15 minutes, followed by hot rolling to a predetermined thickness. 1.0 m thick from hot rolled sheet
m, width 10mm, length 55mm, notch 2mm V-notch A Charpy test specimen is taken in parallel with the rolling direction, and the Charpy impact value is measured at every 25 ° C, and the brittle fracture ratio becomes 50%. The temperature, that is, the transition temperature between ductility and toughness, was determined as an index of toughness.

Next, after the surface of the hot-rolled sheet was treated by shot blast, cold rolling and warm rolling tests were performed. The intermediate annealing was not performed, and the rolling was set to reduce the roll gap by 0.1 to 0.2 mm at a time of one press, and the roll was rolled to a final 0.20 mm. In the case of cold rolling, the hot-rolled sheet was directly rolled at room temperature. In the case of warm rolling, the hot rolled sheet was preheated to 150 ° C. and then rolled. However, in this case, reheating was not performed in the middle. As shown in the results shown in Table 9, when the hot-rolled sheet is thinned, the toughness is significantly improved, and the rollability in cold rolling or warm rolling is improved. This effect is more remarkable as the thickness of the hot-rolled sheet is reduced to 3.0 mm or less.

[0050]

[Table 9]

[0051]

Thus, according to the present invention, the conventional Si
Higher-frequency magnetic properties equal to or higher than those of Fe-Si alloys and Fe-Al alloys up to 6.5 wt% can be ensured together with good workability. In addition, it is advantageous in terms of corrosion resistance and manufacturing cost, and gives an extremely excellent magnetic material overall.

Claims (10)

[Claims] (1) Cr: 1.5 wt% to 20 wt% and Si: 2.5 wt%
high frequency magnetic material characterized by containing not less than 10 wt% and not more than 10 wt%, reducing C and N to not more than 100 wtppm in total, the balance being iron and unavoidable impurities, and having a specific resistance of not less than 60 μΩcm. Fe-Cr-Si alloy with excellent properties. (2) Cr: 1.5 wt% to 20 wt%, Si: 2.5 wt% to 10 wt% and Al: 5 wt% or less, and the total amount of C and N is reduced to 100 wtppm or less. The balance consists of iron and unavoidable impurities and has a specific resistance of 60.
Fe-Cr-Si based alloy with excellent high frequency magnetic properties characterized by being at least μΩcm. (3) Cr: 1.5 wt% to 20 wt% and Si: 2.5 wt%
wt% or more and 10 wt% or less, one or two selected from Mn and P are contained within 1 wt%, respectively, and the total amount of C and N is reduced to 100 wtppm or less, and the balance is iron and iron. An Fe-Cr-Si-based alloy which is composed of unavoidable impurities and has an excellent high-frequency magnetic property, having a specific resistance of 60 μΩcm or more. 4. An alloy containing 1.5 wt% or more and 20 wt% or less of Cr, 2.5 wt% or more and 10 wt% or less of Si and 5 wt% or less of Al, and 1 wt.
% And within 100 wtppm of C and N in total
Reduced to the remainder, consisting of iron and unavoidable impurities,
An Fe-Cr-Si alloy having excellent high-frequency magnetic characteristics, having a specific resistance of 60 µΩcm or more. 5. The Fe—Cr—Si based alloy according to claim 1, wherein the Fe—Cr—Si alloy has a plate thickness of 0.01 to 0.4 mm. 6. Cr: 1.5 wt% or more and 20 wt% or less and Si: 2.5 wt%
containing not less than 10 wt% and not more than 10 wt%, and the total amount of C and N
When rolling a Fe-Cr-Si alloy material reduced to 100 wtppm or less, the thickness is reduced to 3 mm or less by hot rolling, and then the hot-rolled sheet is rolled cold or warm without annealing. A method for producing an Fe-Cr-Si alloy having excellent high frequency magnetic properties. 7. Cr: 1.5 wt% to 20 wt% and Si: 2.5 wt%
containing not less than 10 wt% and not more than 10 wt%, and the total amount of C and N
When rolling a Fe-Cr-Si based alloy material reduced to 100 wtppm or less, high-frequency magnetic characteristics characterized in that cold rolling or warm rolling after hot rolling is performed without intermediate annealing. Method for producing Fe-Cr-Si-based alloys with excellent performance. 8. Cr: 1.5 wt% or more and 20 wt% or less and Si: 2.5 wt%
containing not less than 10 wt% and not more than 10 wt%, and the total amount of C and N
When rolling the Fe-Cr-Si alloy material reduced to 100 wtppm or less, the thickness is reduced to 3 mm or less by hot rolling, and then the hot-rolled sheet is subjected to cold rolling or warm rolling without annealing. A method for producing an Fe-Cr-Si-based alloy having excellent high-frequency magnetic characteristics, wherein cold or warm rolling is performed without performing intermediate annealing. 9. The Fe—Cr—Si alloy according to any one of claims 6 to 8, wherein the Fe—Cr—Si alloy material contains 5 wt% or less of Al. Manufacturing method. 10. The method according to claim 6, wherein the Fe—Cr—Si based alloy material contains one or two selected from Mn and P within 1 wt% each. Manufacturing method of Fe-Cr-Si based alloy with excellent high frequency magnetic properties.