JPH0122325B2 - - Google Patents

Description

[Detailed description of the invention]

This invention is based on Fe-Cr-Co containing high concentration of Cr.
Regarding the manufacturing method of the system magnet alloy, by adding small amounts of Al and N and performing cold rolling and high temperature annealing, a magnet material having a texture in which the axis of easy magnetization of secondary recrystallized grains is aligned in the rolling direction is obtained. It is something. Recently, high Cr Fe―Cr―
Co-based magnetic alloys have been developed. This magnetic alloy has a composition whose main components are 20 to 31% Cr, 6 to 24% Co, and the balance Fe. After solution treatment at high temperature, it is subjected to magnetic field heat treatment such as constant temperature magnetic field treatment and cooling in a magnetic field. This allows so-called spinodal decomposition to be performed, whereby single-domain fine particles of a ferromagnetic phase are precipitated with shape anisotropy in a non-magnetic matrix phase, thereby providing magnetic anisotropy. Unlike ferrite magnets, etc., this magnetic alloy can be rolled, so it is attracting attention as a material that can be used for various purposes. However, it is actually difficult to give the above-mentioned magnetic alloy such high magnetic anisotropy only by spinodal decomposition through heat treatment in a magnetic field, and therefore it is actually difficult to improve its magnetic properties beyond a certain level. Ta. By the way, the alloy according to this invention (Fe-Cr-Co
For silicon steel sheets, i.e., Fe-Si alloys, which have components and compositions that are completely different from those of the Fe-Si alloys, the growth of primary recrystallized grains can be suppressed by adding appropriate additive elements and performing cold rolling and high-temperature annealing. hand
Generates secondary recrystallized grains in which the [100] axis, which is the axis of easy magnetization of the Fe-Si alloy, is aligned in the rolling direction, thereby producing an anisotropic silicon steel sheet with a texture called Goss structure. method is known. A silicon steel sheet having such a Goss structure exhibits high magnetic properties as an anisotropic magnetic material because the integration rate of the [100] axis, which is the axis of easy magnetization, in the rolling direction is extremely high as described above. However, the method for obtaining a Goss structure as described above has only been put to practical use with silicon steel sheets, and has not yet been put into practical use with other alloys. In other words, in general, in alloy materials, if the constituent elements and contents of the alloy differ, the behavior of the metal structure during various treatments and processing will be completely different. It is thought that the method for obtaining the structure is difficult to apply as it is to materials other than silicon steel sheets, and for this reason, it has not been attempted for other alloys. Against the background of the above circumstances, the inventors of this invention believe that if it is possible to obtain a texture similar to the Goss structure in silicon steel sheets for Fe-Cr-Co magnet alloys, it will be possible to obtain high magnetic properties with anisotropy. We thought that it would be possible to obtain a magnetic material of 100%, and conducted extensive research to develop a manufacturing method for it. By adding specific amounts of specific additive elements, we found that it would be possible to obtain a magnetic material that could be cold-rolled and heated at high temperatures in the same way as silicon steel sheets. It was discovered that by annealing, it is possible to obtain a texture in which the [001] axis, which is the axis of easy magnetization, is aligned in the rolling direction in Fe-Cr-Co magnet alloys, and that magnet alloys with this texture actually have high They discovered that it exhibits magnetic properties and came up with this invention. That is, the manufacturing method of the present invention is to add 0.05 to 2% of Al (aluminum) and 0.003 to 0.2% of N (nitrogen) as additive elements to the Fe-Cr-Co-based magnetic alloy, and then cold-roll and high-temperature annealing (110 ) [001] The basic feature is to obtain the texture of the orientation. Such Al and N are dispersed as AlN in the alloy matrix, and their
AlN acts as an inhibitor to the growth of primary recrystallized grains during high-temperature annealing after cold rolling, and prevents the growth of primary recrystallized grains. By generating crystal grains, the texture described above is obtained. Specifically, the manufacturing method of the first invention of the present application uses Al0.05
Fe-Cr containing ~2% (weight%, same below)
-After casting Co-based alloy molten metal, it is cold rolled to 1000℃.
Annealed at a temperature above, and at least contain 0.003 to 0.2% N at the stage before the annealing, resulting in a final product of 20 to 31% Cr, Co6
~24%, Al0.05~2%, N0.003~0.2%,
This method is characterized by obtaining an alloy having a composition in which the balance consists of Fe and unavoidable impurities. Moreover, the manufacturing method of the second invention is to obtain a magnetic alloy having a component composition further containing 28% or less of Mo in addition to the above-mentioned constituent elements specified in the first invention. Furthermore, the manufacturing method of the third invention includes, in addition to each component element specified in the first invention, as a selected ingredient,
Nb2% or less, V4% or less, Ti3% or less, Zr2% or less,
A magnetic alloy having a composition containing one or more of W4% or less is obtained. In addition to the respective component elements specified in the first invention, the manufacturing method of the fourth invention further includes Mo28% or less, Nb2% or less as selected components, V4% or less,
A magnetic alloy having a component composition containing one or more of Ti 3% or less, Zr 2% or less, and W 4% or less is obtained. The manufacturing method of this invention will be explained in more detail below. The Fe-Cr-Co alloy targeted by this invention has 20 to 31% Cr, 6 to 24% Co, and the balance is Fe, but if necessary,
A part of Fe may be replaced with 28% or less of Mo, and if necessary, one or more selected from the following elements may be contained. Nb2% or less, V4% or less, Ti3% or less, Zr2% or less, W4% or less. In this invention, 0.05 to 2% of Al and 0.003 to 0.2% of N are further added to the above-mentioned components. These Al and N are used to generate AlN, which acts as an inhibitor to suppress the growth of primary recrystallized grains during later high-temperature annealing.
Al less than 0.05% and N 0.003% are sufficient amounts.
Since AlN cannot be generated and therefore the effect of suppressing the growth of primary recrystallized grains during high-temperature annealing cannot be obtained, a texture with a (110) [001] orientation cannot be obtained. Moreover, if Al exceeds 2%, the residual magnetic flux density of the finally obtained magnetic alloy will decrease, and if N exceeds 0.2%, cold rolling will become difficult. The above-mentioned Al and N act as inhibitors (AlN) to the growth of primary recrystallized grains during high-temperature annealing after cold rolling, and promote secondary recrystallization, so basically, before high-temperature annealing, It is fine if it is added to AlN and dispersed as AlN.
Since it is difficult to diffusely add a sufficient amount of Fe--Cr--Co alloy after casting, a predetermined amount of Fe--Cr--Co alloy can be added alone or as a master alloy when melting the Fe--Cr--Co alloy molten metal. On the other hand, N may be added by melting it in the air and combining it with Al when melting the molten alloy, or by injecting N ₂ during melting, or by adding nitrogen compounds to the molten alloy. However, since N can be diffused to some extent even in solid phase alloys, it is possible to annealing in a _N2 atmosphere after cold rolling, or in a _N2 atmosphere until the temperature is raised during high-temperature annealing for secondary recrystallization. Alternatively, AlN may be generated by being diffused from the outside after cold rolling by switching to an H ₂ atmosphere after the temperature rise is completed. Of course, a method of adding N to the molten metal and a method of diffusing N after cold rolling may be used in combination. Specific examples of such nitrogen addition means include the following methods (a) to (e). (a) When melting the alloy, chromium nitride is mixed with Fe, Cr,
Add after Co and other additives have melted off. In this case, when chromium nitride decomposes after addition of chromium nitride, a portion of the nitrogen in chromium nitride is often lost, so it is necessary to predict the amount of nitrogen that will be lost before adding. In order to improve this addition yield,
It is also effective to increase the pressure in the melting furnace with an inert gas (usually helium or argon). (b) During alloy melting, nitrogen gas is introduced into the melting furnace and nitrogen is dissolved into the molten metal. It is also effective to blow nitrogen gas into the molten metal using a lance in order to promote the dissolution of nitrogen into the molten metal. (c) After solidifying the alloy, the alloy is heated to a high temperature and exposed to a nitrogen atmosphere or a nitrogen-containing atmosphere such as ammonia, thereby dissolving nitrogen from the surface. However, in this case, in order to prevent the nitrided layer from being concentrated only on the surface, it is desirable to perform annealing for homogenization after the nitriding process. (d) As a method for adding nitrogen after alloy solidification, the method used as a general nitriding method for steel materials, that is, NaCN, which is a nitrogen-containing compound,
It is also possible to use a method in which KCN, NaCNO, etc. are melted and immersed in the melt to form a nitride layer on the surface. In this case as well, as in the case (c) above, it is desirable to perform annealing for homogenization. In this case, it is also effective to add chloride or the like to promote nitridation. (e) It is also effective to use the ion nitriding method, which is applied to steel materials, especially completed or semi-finished molds. The alloy melt to which the necessary components have been added and produced as described above is cast into an ingot by an appropriate casting method, and then cold rolled and subjected to high temperature annealing heat treatment. Of course, before cold rolling, the ingot is often subjected to hot rolling or hot forging to form a plate material of a predetermined thickness, but these steps will not be described in detail here. The cold rolling is preferably performed until the rolling rate (processing rate) reaches 40% or more. If it is less than 40%, the recrystallized structure will not be sufficiently generated during annealing after rolling, and therefore the magnetic properties will not be sufficiently improved. In addition, in order to obtain a more complete texture, that is, a secondary recrystallized structure with a high accumulation rate of the [001] axis in the rolling direction, it is desirable to repeat cold rolling and annealing two or more times, but in some cases So it's 1
It may be only a few times, and the key point is to decide based on the balance between the degree of texture depending on the desired magnetic properties and the manufacturing cost. The high-temperature annealing heat treatment after rolling is for secondary recrystallization, and the annealing temperature must be 1000°C or higher. If the temperature is lower than 1000°C, the secondary recrystallization after the primary recrystallization will not be carried out smoothly. In addition, when cold rolling and annealing are repeated two or more times, it is sufficient that secondary recrystallized grains are generated in the last annealing treatment, so the temperature of the last annealing treatment should be set within the above range, and the temperature of the previous annealing treatment should be set within the above range. The intermediate stage annealing is
It may be less than 1000℃. In addition, secondary recrystallization usually starts after a certain incubation period has passed after primary recrystallization grains are formed, so it is desirable to carry out annealing for 0.25 hours or more, and for 2 hours. Even if it is annealed beyond this point, there is no industrial merit. During annealing after cold rolling as described above, primary recrystallization is initially performed to generate fine primary recrystallized grains. The subsequent growth of normal primary recrystallized grains is suppressed by the AlN dispersed within the base, and after a certain incubation period, the crystal grains whose [001] axis is oriented in the rolling direction That is, crystal grains with (110) [001] orientation grow rapidly, resulting in the so-called secondary recrystallization phenomenon. Therefore, a texture with (110) [001] orientation is obtained by secondary recrystallization. After annealing for secondary recrystallization, solution treatment is usually performed to make the structure one-phase. This solution treatment can be done by quenching from about 1000℃ to 1300℃, but
In order to destroy the texture obtained by the above-mentioned secondary recrystallization to generate randomly oriented crystals or to prevent the growth of crystals oriented away from the desired direction, it is necessary to The heat treatment temperature is desirably lower than the secondary recrystallization temperature. It is also possible to perform solution treatment using the cooling process immediately after annealing for secondary recrystallization, in which case heating is performed only for solution treatment after annealing for secondary recrystallization. There will be no need. After the solution treatment as described above, heat treatment in a magnetic field and aging treatment are usually performed in order to obtain even better magnetic properties. In other words, conventionally high Cr
As proposed for Fe-Cr-Co magnet alloys, constant temperature heat treatment at 630°C to 700°C in a magnetic field is performed for about 0.25 to 4 hours, and then at around 600°C.
Aging treatment is performed for about 0.5 to 5 hours. In this way, a single magnetic domain ferromagnetic phase is dispersed and precipitated in the nonmagnetic phase due to spinodal transformation, and the single domain ferromagnetic phase particles are aligned in the direction of the magnetic field.
Here, as described above, after cold rolling and annealing for secondary recrystallization, a texture is obtained in which the [001] axis, which is the axis of easy magnetization, is aligned in the rolling direction. Therefore, the magnetic field is further applied to the alloy in the rolling direction ([001]
If heat treatment and aging treatment are performed in a magnetic field while applying the axial direction), the above-mentioned texture and the effect of the magnetic field treatment will combine to form single-domain ferromagnetic phase particles with a significantly high orientation rate. [001] is deposited in the axial direction, resulting in a magnet alloy with significantly high anisotropic magnetic properties. Examples of this invention are described below. Example 1 Alloys with eight types of compositions shown in Table 1 (however,
In the notes column of the table, ○ marks are alloys within the composition range of the present invention, ×
The alloys (marked with the mark are alloys outside the composition range of the present invention) were melted and cast, hot forged to form a plate with a thickness of 5 mm, and then water-cooled from 1300°C to make the structure one-phase. Then, it was cold rolled until the thickness was 0.5 mm. The obtained thin plate material was placed in wet hydrogen with a dew point of +30°C.
It is heated to 1050℃ for decarburization treatment, and further heated to 1300℃.
After annealing at ℃ for 5 hours and performing secondary recrystallization, each sample of No. 1-1 to No. 2-2 was heated to 1100℃.
℃, and for samples No. 2-3 and 2-4.
Each was quenched in cold water from 1000℃. Next, constant temperature treatment in a magnetic field and aging treatment were performed at the optimum temperature for each alloy. The constant temperature treatment temperature in a magnetic field and the aging treatment temperature for each alloy are shown in the left column of Table 2. The constant temperature treatment in a magnetic field was carried out at each temperature for 3 hours, and the aging treatment was carried out at each temperature for 10 hours. The results of measuring the magnetic properties of each of the obtained magnet alloys are shown in the right column of Table 2. From Table 2, it is clear that the magnetic alloys in which Al and N are added within the above-mentioned ranges have higher magnetic properties than those in which the amounts of Al and N added are outside the above-mentioned ranges.

【table】

[Table] Example 2 Molten metals having alloy components shown in sample numbers 3-1 and 3-2 in Table 3 were melted, cast, and treated under the same conditions as in Example 1 to produce magnet alloys. Here, nitrogen was added by adding chromium nitride during melting. The quenching after secondary recrystallization annealing is performed from 1100℃, and the constant temperature treatment temperature in a magnetic field is
The aging treatment temperature is as listed in Table 4. Example 3 Molten metals having alloy components shown in sample numbers 4-1 and 4-2 in Table 3 were melted, cast, and treated under the same conditions as Example 1 to obtain magnet alloys. Here, nitrogen was added by blowing nitrogen gas into the molten metal through a ceramic lance during melting. The quenching after the secondary recrystallization annealing was performed from 1100°C, and the temperature of the constant temperature treatment in a magnetic field and the temperature of the aging treatment were as shown in Table 4. Example 4 Fe-Cr-Co-Al alloy was melted by a conventional method, cast, rolled to a thickness of 0.5 mm, and then NaCl30
%, CuCl ₂ 60%, and CaCN ₂ 10% in a salt bath at 600° C. for nitriding.
After the nitriding treatment, it was further homogenized at 1000℃ for 10 hours, then cold-rolled to a thickness of 0.25mm, and then subjected to secondary recrystallization annealing at 1200℃ for 30 minutes, and subjected to constant temperature treatment in a magnetic field and aging treatment. Summer. The component composition after the nitriding treatment at this time is sample number 5 in Table 3.
-1. For comparison, sample number 5-2 in Table 3 shows the composition of a sample in which the nitriding treatment was not performed and the other steps were the same as above. Furthermore, in the above process, nitriding treatment is performed by 0.5mm.
Sample No. 5-3 in Table 3 shows the composition of a sample in which the same nitriding treatment was performed at the stage of cold rolling to a thickness of 0.25 mm, but not at the thickness stage. Table 4 shows the results of examining the magnetic properties of the samples obtained in Examples 2 to 4 above.

【table】

[Table] Example 5 Alloys having the compositions shown in sample numbers 6 to 10 in Table 5 were melted and cast in the following manner. That is, Al
The raw materials for melting except for the additive raw materials of N are blended and melted in a high-frequency melting furnace filled with 1 atm of argon gas. After melting, 0.1% Al is added, and after 3 minutes, chromium nitride is added to ensure complete melting. It was then cast into a cast iron mold. This ingot was rolled to 3 mm and then annealed at 1200° C. for 30 minutes in an argon gas atmosphere for secondary recrystallization. Thereafter, it was subjected to constant temperature treatment in a magnetic field at 650°C for 3 hours, and further subjected to aging treatment at 630°C for 10 hours. Table 6 shows the results of examining the magnetic properties of each alloy.

【table】

[Table] As is clear from the above explanation, according to the manufacturing method of the present invention, an anisotropic Fe-Cr-Co magnet alloy having a texture in which the [001] axis, which is the axis of easy magnetization, is aligned in the rolling direction. Therefore, an effect is obtained in which an anisotropic magnet material having high magnetic properties can be practically produced.

Claims (1)

[Scope of Claims] 1. A molten Fe-Cr-Co alloy containing 0.05 to 2% (by weight, same hereinafter) of Al is cast, then cold rolled and annealed at a temperature of 1000°C or higher, and N0.003~0.2% at least at the stage before the annealing
By this, Cr20 ~
31%, Co6~24%, Al0.05~2%, N0.003~0.2
%, with the remainder consisting of Fe and unavoidable impurities. 2 After casting a molten Fe-Cr-Co alloy containing 0.05 to 2% Al, it is cold rolled and annealed at a temperature of 1000°C or higher, and at least 0.003 to 0.2% N is added at a stage before the annealing. This results in a final content of 20 to 31% Cr, 6 to 24% Co,
A method for producing a magnetic alloy, characterized by obtaining an alloy having a composition containing 28% or less of Mo, 0.05 to 2% of Al, and 0.003 to 0.2% of N, with the balance consisting of Fe and inevitable impurities. 3 After casting a molten Fe-Cr-Co alloy containing 0.05 to 2% Al, it is cold rolled and annealed at a temperature of 1000°C or higher, and at least 0.003 to 0.2% N is added at a stage before the annealing. This results in a final content of 20 to 31% Cr, 6 to 24% Co,
Contains Al0.05~2%, N0.003~0.2%, and
Nb2% or less, V4% or less, Ti3% or less, Zr2% or less,
Contains one or more of W4% or less,
A method for producing a magnetic alloy, characterized by obtaining an alloy having a composition in which the remainder consists of Fe and unavoidable impurities. 4 After casting a molten Fe-Cr-Co alloy containing 0.05 to 2% Al, it is cold rolled and annealed at a temperature of 1000°C or higher, and at least 0.003 to 0.2% N is added at a stage before the annealing. This results in a final content of 20 to 31% Cr, 6 to 24% Co,
Contains Mo28% or less, Al0.05-2%, N0.003-0.2%, and Nb2% or less, V4% or less, Ti3% or less,
A method for producing a magnetic alloy, characterized by obtaining an alloy having a composition containing one or more of Zr 2% or less and W 4% or less, with the balance consisting of Fe and inevitable impurities.