JPH0841569A - Magnetic alloy tube and its production - Google Patents

Abstract

PURPOSE:To produce a thin-wall magnetic alloy tube by using 2V Permendur(R). CONSTITUTION:A tube stock of a magnetic alloy having a composition consisting of, by weight, 45-55% Co, 1-3% V, and the balance essentially Fe is used. This tube stock is temporarily heated to 900-1200 deg.C and then cooled down to <=400 deg.C at a rate of >=200 deg.C per second to undergo hardening treatment. Further, cold working and magnetic annealing are performed. By this method, the thin-wall magnetic alloy tube having high saturation magnetic flux density 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 magnetic alloy tube and a method for manufacturing the same, and more particularly to a magnetic alloy tube having a high saturation magnetic flux density, a method for manufacturing the same and a vibrator motor using the magnetic alloy tube.

[0002]

2. Description of the Related Art Conventionally, pure iron has been used for a yoke of a cylindrical coreless motor for a pager (vibe motor, hereinafter referred to as vibe motor). The yoke used in such a vibrator motor has a tubular shape, and has a small size, for example, an outer diameter of 6 mm and a wall thickness of 0.04 mm. Pure iron is used as a material for such a yoke because pure iron has a relatively high saturation magnetic flux density (1.7 T) and also has good workability and is easy to manufacture a thin-walled tube. In recent years, miniaturization of a vibe motor has been studied in response to the need for miniaturization of a pager. Here, in order to reduce the size of the vibrator motor, it is necessary to reduce the thickness of the yoke, but in this case, the conventional yoke made of pure iron has a problem that the saturation magnetic flux density is insufficient. Therefore, in order to reduce the size of the vibrator motor, a magnetic alloy having a higher saturation magnetic flux density than pure iron is desired as a material for the yoke.

On the other hand, Co 45-55% by weight, V1-
A magnetic alloy containing 3% and the balance being substantially Fe,
As a magnetic alloy having a high saturation magnetic flux density (2.4T),
It is known by the name of 2V permendur and is used for various yokes, cores, etc. for motors.

[0004]

Therefore, in order to miniaturize the vibrator motor, it is desirable to form a cylindrical yoke by using this magnetic alloy having a saturation magnetic flux density higher than that of pure iron.

Generally, this magnetic alloy is melted and cast by vacuum melting, hot-worked, quenched, and further cold-worked into a plate or linear shape, and then punched, machined, etc. It is used after being molded into a magnetically annealed material.

The structure of the above magnetic alloy has a γ phase at about 1000 ° C. or higher, an α phase + γ phase at 900 ° C. to 1000 ° C., and a 700 phase.
It becomes an α phase at ℃ to 900 ° C and an α'phase (ordered lattice) at 700 ° C or lower.

Here, good magnetic properties of the above magnetic alloy can be obtained in the α'phase, but since the α'phase is an ordered lattice, the toughness is poor, and plastic working in this phase is difficult. Therefore,
In the manufacturing method described above, quenching after hot working is performed by heating and holding once to a phase temperature at which the α'phase is not generated and then rapidly cooling from that temperature, and α'generated by cooling after hot working is generated. This is because the phase disappears. Generally, ice water is used as a cooling medium for quenching. Thus, the magnetic alloy in which the generation of the α'phase is suppressed is subjected to cold working, and finally magnetic annealing is performed to generate the α'phase, thereby obtaining good magnetic properties.

On the other hand, pipes are generally classified into welded pipes and seamless pipes. The manufacturing method of the welded pipe is a method of rolling an annealed thin plate and welding the seam, but in the case of the above 2V permendur, there is an α'phase ordered at 700 ° C or lower, At the normal annealing cooling rate, the α'phase is generated and becomes brittle, which makes bending difficult. Bending can be performed by quenching the magnetic alloy plate, but by quenching a thin plate, the deformation is remarkable, which makes it difficult to manufacture a stable tube.

On the other hand, as a method for producing a seamless pipe, there is drawing rolling. However, since the processing speed is high in the usual stretch-rolling method, the deformability of the 2V permendur tube material does not follow, and cracks are likely to occur.

On the other hand, in the case of a relatively short tube, a method of deep drawing an annealed plate can be considered. However, even with this method, it is necessary to anneal the material to soften it, but since the above-mentioned magnetic alloy cannot be subjected to normal industrial anneal as described above, deep drawing is also difficult. Further, even if the above-mentioned magnetic alloy plate is quenched, it does not show sufficient elongation for deep drawing.

As described above, there is a problem that the 2V permendur cannot be used as the yoke of the vibe motor because there is currently no good means for producing the thin-walled tube made of the 2V permendur described above.

An object of the present invention is to provide a thin-walled magnetic alloy tube using 2V permendur which is optimal as a yoke of a small-sized vibe motor and a manufacturing method thereof.

[0013]

According to the present invention, the weight percent is
A magnetic alloy tube characterized in that it contains 45 to 55% of Co and 1 to 3% of V, and the balance is substantially Fe, and is cold worked.

Further, according to the present invention, Co45 by weight% is used.
˜55%, V1˜3%, and the balance is magnetic alloy tube material consisting essentially of Fe, once heated to a temperature of 900 ° C. to 1200 ° C., and then 40% at a rate of 200 ° C. or more per second.
A thin magnetic alloy tube having a high saturation magnetic flux density can be obtained by performing a quenching process of cooling to 0 ° C. or lower, and further performing magnetic annealing after cold working.

That is, Co 45-55% by weight, V1-
A magnetic alloy tube material containing 3% and the balance being substantially Fe is heated to a temperature of 900 ° C to 1200 ° C once, and then cooled to 400 ° C or less at a rate of 200 ° C or more per second, and then cooled. A magnetic alloy tube characterized by having a surface reduction rate of 10% or more was obtained by hot working, and the outer diameter was 1
A magnetic alloy tube having a thickness of 5 mm or less and a wall thickness ratio to the outer diameter of 25% or less is obtained.

Further, according to the present invention, particularly during the cold working, a plurality of rolls reciprocatingly rotating in the longitudinal direction of the pipe material, guides connected to them, and the pipe material are penetrated. A magnetic alloy pipe for adjusting the wall thickness and diameter of the pipe material to be processed under appropriate conditions by a draw rolling method in which at least one of the pipe material and the mandrel independently rotates using a mandrel. A manufacturing method is obtained.

[0017]

The reason why the content of Co is 45 to 55% by weight is that high magnetic permeability cannot be obtained outside this range. Further, V is an element for suppressing the formation of ordered lattice during quenching, but the reason why V is set to 1 to 3% is that if V is less than 1%, the formation of ordered lattice cannot be suppressed, and quenching is performed. Is difficult, and when V exceeds 3%, the coercive force remarkably increases and it becomes impossible to use as a high magnetic permeability alloy.

The quenching temperature of 900 ° C. to 1200 ° C. is because it is difficult to suppress the production of α ′ phase industrially at less than 900 ° C., and cracks occur during the subsequent rolling process. If the temperature exceeds ℃, the deformation of the tube material will be significant, which will hinder the subsequent rolling process.

The cooling rate of 200 ° C./sec or more is 2
This is because if it is less than 00 ° C / sec, the α'phase is remarkably formed, and sufficient ductility cannot be obtained in the subsequent cold working.

As for the tube material, a rod material obtained by hot working or cold working may be machined into a cylindrical shape, or a quenched material may be machined into a cylindrical shape. If you want to machine the hardened material,
In some cases, subsequent quenching may be omitted.

Further, after the above-mentioned magnetic alloy plate (here, a plate having a thickness which is not significantly deformed even if it is hardened) is hardened, the plate is rounded, a seam is welded, and α is generated by cooling after welding. ′ After quenching again to eliminate the phase,
It may be cold worked.

The total area reduction rate in cold working is 10%.
The above is desirable. This is because by taking the total surface reduction rate of 10% or more, the scale formed on the material surface during quenching can be removed and the tube surface can be made smooth. In particular, in the case of a welded pipe material, it is necessary to destroy the weld structure so as not to adversely affect the magnetic properties and mechanical properties, and for that reason, a total area reduction rate of 10% or more is required.

When the cold working is stretch rolling, 1
The area reduction rate per pass is preferably 10% or more. This is because if the area reduction rate is less than 10%, the stress applied to the tube material is non-uniform and cracking is likely to occur. Further, it is necessary to increase the area reduction rate and the roll reciprocating stroke. This is because the tube material is not suddenly deformed. For example, when a roll having an outer diameter of 30 mm is used and the area reduction rate is 10%, it is desirable that the stroke of the roll is 100 mm or more in terms of effective working length. Here, the effective processing length is a section in which the pipe material is processed (the distance from the processing start to the processing end), and is different from the distance that the roll actually reciprocates.

Regarding the roll diameter, it is desirable to make one rotation or more during the effective processing length. This is to avoid uneven wear of the roll.

The difference between the inner diameter of the tube material and the outer diameter of the mandrel, that is, the clearance is preferably 20% or less of the inner diameter of the tube material. This is because if the clearance exceeds 20% of the inner diameter of the tube material, it becomes less compatible with the mandrel and the roundness decreases.

By the drawing and rolling method as described above, a tube having a good 2V permendur can be obtained. This method is particularly suitable for a thin wall tube having an outer diameter of 15 mm or less and a wall thickness of 25% or less of the outer diameter.

The magnetic alloy tube thus obtained was processed into a desired shape based on a cylindrical shape, and after heating and holding at 750 ° C. to 900 ° C. in a non-oxidizing atmosphere,
By cooling at a cooling rate of 400 ° C. or less per hour to 400 ° C. or less, a magnetic alloy based on a cylindrical shape such as a yoke of a vibe motor can be obtained. Here, the heating temperature is set to 750 ° C. to 900 ° C. because it is 900
This is because if the temperature exceeds ℃, the γ phase precipitates and the magnetic properties deteriorate, and if it is lower than 750 ° C, the fiber structure during rolling remains. The cooling rate is set to 400 ° C. or less per hour because if it exceeds this rate, the α ′ phase is not sufficiently formed and good magnetic properties cannot be obtained.

The cooling rate below 400 ° C. does not adversely affect the magnetic properties.

[0029]

EXAMPLES Examples of the present invention will be described in detail below.

Example 1 A 2V permendur obtained by the high frequency vacuum melting method was hot worked into a rod having an outer diameter of 20 mm and then machined into a cylindrical body sample having an outer diameter of 15 mm and an inner diameter of 11 mm. Next, 800 ° C, 900 ° C, 1000 ° C, 1100
After being kept at each temperature of ℃, 1200 ℃ and 1300 ℃, it was quenched in ice water. Cooling rate during quenching is 1
It was set to 00 ° C./second, 200 ° C./second, and 300 ° C./second. After that, it was rolled by a stretch rolling machine to an outer diameter of 4 mm and an inner diameter of 3.6 mm. The area reduction rate per pass at this time is 2
It was set to 0%. This rolling mill has two or three rolls arranged in parallel to the sample, appropriately adjusts the reciprocal movement and the rotation forward and backward with respect to the sample, and further inserts a mandrel into the cylindrical inner diameter of the sample. Alternatively, the stretching rolling is performed while rotating the sample and the mandrel independently of each other. The results are shown in Table 1.

[0031]

[Table 1]

From this table, in order to obtain good workability,
The quenching temperature (° C) is set to 900 ° C to 1200 ° C, and the quenching speed, that is, the cooling rate (° C / sec) during quenching is 200 ° C.
It was confirmed that it is preferable to set it to be not less than / second.

Example 2 A 2V permendur obtained by the high-frequency vacuum melting method was hot worked into a rod having an outer diameter of 20 mm and then machined into a cylindrical body sample having an outer diameter of 15 mm and an inner diameter of 11 mm. Next, after heating and holding at a temperature of 1000 ° C., it was quenched in ice water. The cooling rate during quenching was 300 ° C./sec. Then, using a drawing and rolling machine, the outer diameter was 4 mm and the inner diameter was 3.
Rolling was performed to 6 mm. The area reduction rate per pass at this time was 5%, 10%, 30%, and 50%. The same stretch rolling machine as in Example 1 was used. The results are shown in Table 2.

[0034]

[Table 2]

From this table, in order to obtain good workability,
It was confirmed that it is desirable to set the area reduction rate (%) to 10% or more.

Example 3 A 2V permendur obtained by the high-frequency vacuum melting method was hot-worked, then quenched and cold-worked into a plate having a thickness of 1.5 mm. Here, after quenching, after bending into a cylinder with an outer diameter of 15 mm, by TIG welding,
Welded the seams. After that, quenching was performed, and rolling was performed by a stretch rolling machine to an outer diameter of 4 mm and an inner diameter of 3.6 mm. The same stretch rolling machine as in Example 1 was used. The conditions for quenching are the same as in Example 2 above.

Further, the magnetic alloy tube thus obtained is set to a length of 7 m.
After cutting to m (apart from cracks if partially cracked) and performing magnetic annealing, magnetic characteristics were measured with a BH tracer. Table 3 shows the results.

[0038]

[Table 3]

From this table, in the case of welded pipe material,
It was confirmed that the total area reduction rate (%) should be 10% or more in order to prevent the welded structure from adversely affecting the magnetic properties and mechanical properties of the magnetic alloy pipe.

Example 4 A 2V permendur obtained by the high-frequency vacuum melting method was hot worked into a rod having an outer diameter of 20 mm and then machined into a cylindrical body sample having an outer diameter of 15 mm and an inner diameter of 11 mm. Next, after heating and holding at a temperature of 1000 ° C., it was quenched in ice water. The cooling rate during quenching was 300 ° C./sec. Then, with a drawing and rolling machine, the outer diameter is 6 mm and the inner diameter is 5.
Rolling was performed to 2 mm. The area reduction rate per pass at this time was 30%. In addition, this stretch rolling machine is also used in Example 1.
The same as was used. Then, it was machined into a yoke shape similar to that of a conventional pager vibe motor (cylindrical coreless motor) having an outer diameter of 6 mm, and magnetic annealing was performed. The yoke of the 2V permendur thus obtained was incorporated into a conventional vibe motor by replacing only the yoke, and the performance was compared with that of the conventional vibe motor. The results are shown in Table 4.

[0041]

[Table 4]

From this table, the pager vibe motor using the product of the present invention has a starting torque which is 30% larger than that of the conventional product.
Moreover, it has been found that the power consumption can be reduced by 20%.
It is presumed that such an effect is due to the fact that the saturation magnetic flux density of the yoke material of the present invention is higher than that of the conventional product, so that the effective saturation magnetic flux passing through the yoke is increased.

Therefore, by applying the magnetic alloy tube of the present invention, the motor having the same performance as the conventional one can be reduced in outer diameter, that is, downsized. Further, if the shape is the same as that of a conventional motor, the power consumption is small, so that the replacement cycle of the motor drive battery can be extended,
As a result, the life of the pager itself can be extended.

[0044]

As described above, according to the present invention,
It is possible to provide a thin-walled magnetic alloy tube having a high saturation magnetic flux density that is optimal for a yoke or the like of a vibrator motor (cylindrical coreless motor).

It is easily inferred that the magnetic alloy tube of the present invention is applied to a vibrator motor having a cored motor structure.

The application of the magnetic alloy tube of the present invention is not limited to the vibe motor, but it goes without saying that it can be applied to all parts and products using a cylindrical yoke.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C22C 38/12 C22F 1/10 J H01F 3/00

Claims (10)

[Claims] 1. By weight%, Co is 45 to 55%, and V is 1 to 3%.
And a balance is substantially made of Fe and is cold worked. 2. The magnetic alloy pipe according to claim 1, wherein the outer diameter is 15 mm or less and the wall thickness ratio to the outer diameter is 25%.
A magnetic alloy tube characterized in that: 3. Co45-55% and V1-3% by weight
A tube material of a magnetic alloy containing, and the balance being substantially Fe, is once heated to a temperature of 900 ° C. to 1200 ° C., and then 1
A magnetic alloy tube characterized by being cooled to 400 ° C. or less at a rate of 200 ° C. or more per second and then cold-worked to have a surface reduction rate of 10% or more. 4. Co45-55%, V1-3% by weight
A step of heating a tube material of a magnetic alloy containing substantially the same as Fe to a temperature of 900 ° C. to 1200 ° C., and heating the heated tube material to 400 ° C. at a rate of 200 ° C. or more per second.
A method for producing a magnetic alloy tube, comprising: a step of cooling to a temperature equal to or lower than 0 ° C .; and a cold working step of working the cooled tube material by a cold working to reduce an area of 10% or more. 5. The method for manufacturing a magnetic alloy pipe according to claim 4, wherein the cold working step includes a plurality of rolls that reciprocally rotate in the longitudinal direction of the pipe material, and a guide connected to the plurality of rolls. , Using a mandrel penetrating the tube material, at least one of the tube material and the mandrel is performed according to a stretching rolling method independently rotating,
A method for producing a magnetic alloy tube, characterized in that the wall thickness and diameter of the tube material to be processed are adjusted. 6. The method for producing a magnetic alloy tube according to claim 5, wherein the reduction ratio of the cross-sectional area of the tube material in the drawing and rolling method is 10% or more per one pass. Manufacturing method. 7. The method for manufacturing a magnetic alloy tube according to claim 5, wherein the reciprocating strokes of the plurality of reciprocating rolls in the drawing and rolling method are 100 mm or more in effective working length, and the rolls at that time are in the stroke. A method for manufacturing a magnetic alloy tube, which has an outer diameter that allows one rotation or more. 8. The method according to claim 5, wherein the difference between the inner diameter of the tube material and the outer diameter of the mandrel in the drawing and rolling method is 20% or less of the inner diameter of the tube material. Method for manufacturing alloy pipe. 9. A magnetic alloy tube obtained by any one of claims 3 to 8 is processed into a desired shape based on a cylindrical shape,
A magnetic alloy based on a cylindrical shape, which is characterized by being heated and maintained at 750 to 900 ° C. in a non-oxidizing atmosphere and then cooled to 400 ° C. or less at a rate of 400 ° C. or less per hour. 10. A vibe motor using the magnetic alloy according to claim 9 as a yoke.