JP4023088B2 - Soft magnetic steel sheet for electromagnet actuator parts and manufacturing method thereof - Google Patents

Description

【００３９】
【表２】

【００４０】
【実施例２】
本例においては表３に示す化学組成よりなるスラブを用いて実施例１を繰り返した。結果は表４にまとめて示す。
【００４１】
【表３】

【００４２】
【表４】

【００４３】
【発明の効果】
以上説明したように、本発明によれば、鋼組成および磁気焼鈍後の結晶粒径を特定範囲に規定することで磁気特性と制音性とに優れた軟磁性鋼板が得られ、その製造に当たっても、通常のスラブ加熱、熱間圧延、冷間圧延、焼鈍そして調質圧延と慣用手段でもって行えばよく、低コストで製造が可能となる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a soft magnetic steel sheet used as a yoke of an electromagnetic actuator used for a relay or for valve control in an automobile, and a method for manufacturing the same.
[0002]
[Prior art]
Soft magnetic steel sheets are generally used as iron cores for electromagnets, such as in the yokes of such electromagnet actuators, particularly solenoid yokes.
[0003]
Conventional DC electromagnets are difficult to adjust the current, so only ON-OFF control has been the mainstream. However, when position control at an intermediate position is required as in valve control or the like, since the attraction force of the electromagnet is proportional to the generated magnetizing force, that is, current, current control is required. In recent years, with the development of inverter control, electromagnets can also be controlled by alternating current.
[0004]
Therefore, such current control is easy if AC conversion is performed by inverter control, but until now, inverters are expensive and have not become widespread. However, with the recent widespread use of inverters, such position-controllable electromagnets can be greatly reduced in cost, and even small parts can be used.
[0005]
[Problems to be solved by the invention]
As described above, the electromagnet capable of controlling the current with an alternating current has a problem different from that of the conventional direct current.
[0006]
In other words, in the prior art, for example, there are electromagnetic soft iron plates specified in JIS C 2504 and electromagnetic silicon iron plates specified in the Electronic Materials Industry Association Standards EMAS-1007. It has a very smooth surface with a surface roughness of about 0.1 μm, and it is easy to slip and generate sound. It is difficult to further expand the range of use due to high manufacturing costs and the problem of “sound” when using an inverter. It was.
[0007]
An object of the present invention is to provide a soft magnetic steel sheet for an electromagnet actuator part that is low in cost, excellent in magnetic properties, and excellent in sound damping, and a method for manufacturing the same.
[0008]
[Means for Solving the Problems]
In order to solve such a problem, the present inventors have conducted various studies. As a result, the sound is caused by magnetostriction and electromagnetic attraction force. In either case, the sound is amplified in the yoke by “resonance”. I understood it. However, when the conventional electromagnetic soft iron plate is subjected to “cold working” such as drawing or bending, the crystal grain size after magnetic annealing is reduced and the propagation of “sound” is improved. In addition, the smooth surface was easy to slip, making it easier to generate sound.
[0009]
On the other hand, the magnetic silicon steel plate originally had a small crystal grain size and had good sound transmission and poor sound damping.
Thus, the present inventors have found that the above-mentioned problems can be achieved at low cost by controlling the components, surface finishing, and optimizing the crystal grain size after magnetic annealing.
[0010]
More specifically, by such means, the magnetic flux density when the magnetic characteristic by non-sinusoidal excitation of an inverter or the like is a magnetizing force 10e is 0.5 T or more, the magnetic flux density at 200 e is 1.6 T or more, and the magnetic flux density 1.5 T It was found that good results were obtained with a coercive force of 70 A / m or less and a sound of electromagnetic attraction and magnetostriction of 45 db or less.
[0011]
The gist of the present invention is as follows.
(1) In mass%,
C: 0.01% or less, Si: 0.05% or more and 3.0% or less, Mn: 0.08% or more and 2.5% or less,
S: 0.01% or less, acid-soluble Al: 3.0% or less, P: 0.1% or less,
N: 0.0050% or less,
And 0.1 ≦ [Si] + [Al] + 0.5 × [Mn] ≦ 4.5
Has a steel composition consisting of balance of Fe and unavoidable impurities, the grain size after the magnetic annealing is at 30μm or 2.0mm or less, the average surface roughness Ra: is 0.3μm or more, bending or squeezing processing is given electromagnetic actuator parts soft magnetic steel plate that.
[0012]
(2) In mass%,
C: 0.01% or less, Si: more than 0.5%, 3.0% or less, Mn: 0.08% or more, 2.5% or less,
S: 0.01% or less, acid-soluble Al: 3.0% or less, P: 0.1% or less,
N: 0.0050% or less,
And 0.1 ≦ [Si] + [Al] + 0.5 × [Mn] ≦ 4.5
A soft magnetic steel sheet for an electromagnet actuator part which has a steel composition composed of the remaining Fe and inevitable impurities and has a crystal grain size after magnetic annealing of 30 μm or more and 2.0 mm or less, which is subjected to bending or drawing .
[0013]
(3) Used in applications where AC magnetization is performed by an inverter, using a power source with a PWM waveform with a fundamental frequency of 50 Hz and a carrier frequency of 1 kHz, and having excellent sound damping performance when the sound pressure when excited at 1.0 T does not exceed 45 db. The soft magnetic steel sheet for an electromagnet actuator part according to the above (1) or (2).
(4) After heating the slab having the steel composition described in (1) or (2) above at a temperature of 1300 ° C or less and performing hot rolling, cold rolling is performed once or twice with intermediate annealing. The above-mentioned (1) to (3), characterized in that the final plate thickness is obtained and then continuous annealing or batch annealing is performed at 600 ° C. to 1050 ° C., and then temper rolling is performed at a reduction rate of 15% or less. The method for producing a soft magnetic steel sheet for an electromagnet actuator part according to any one of the above.
[0014]
(5) After heating the slab having the steel composition described in the above (1) or (2) at a temperature of 1300 ° C. or less and performing hot rolling, after performing hot-rolled sheet annealing at 600 ° C. to 1000 ° C., Perform cold rolling once or twice or more with intermediate annealing to the final thickness, then perform continuous annealing or batch annealing at 600 ° C to 1050 ° C, and then temper at a reduction rate of 15% or less Rolling is performed, The manufacturing method of the soft magnetic steel plate for electromagnet actuator components in any one of said (1)-(3) characterized by the above-mentioned.
(6) A slab having the steel composition described in (1) or (2) above is heated at a temperature of 1300 ° C. or lower and hot rolled, and then temper rolled at a reduction rate of 15% or less. The method for producing a soft magnetic steel sheet for electromagnet actuator parts according to any one of (1) to (3) above.
(7) After heating the slab having the steel composition described in (1) or (2) above at a temperature of 1300 ° C or less and performing hot rolling, 600 ° C to 1000 ° C hot-rolled sheet annealing or finish annealing is performed. The method for producing a soft magnetic steel sheet for electromagnet actuator parts according to any one of the above (1) to (3), wherein temper rolling is performed at a rolling reduction of 15% or less.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, a slab made of a predetermined component is hot-rolled and then pickled and cold-rolled, or hot-rolled sheet annealing is performed and cold-rolled after pickling to obtain a predetermined thickness. At the time of cold rolling, it may be finished to a predetermined thickness by one or intermediate annealing and by cold rolling two or more times.
[0016]
Cold-rolled sheets are subjected to recrystallization annealing by continuous annealing or batch annealing, and then temper rolling with a rolling reduction of 15% or less.
As a modified example, temper rolling of 15% or less may be performed continuously on the hot-rolled sheet while pickling or with hot-rolled sheet annealing after pickling.
[0017]
The reasons for limiting the steel composition and production conditions as described above are shown below. In the present specification, “%” is “% by mass” unless otherwise specified.
<Steel composition>
C:
If C is contained in excess of 0.01%, magnetic aging occurs and magnetic properties are deteriorated, so the content is made 0.01% or less. Preferably it is 0.005% or less.
[0018]
Si:
Si is an essential element for improving the magnetic properties, but if it exceeds 3.0%, Vickers hardness is increased and cracking during iron core processing is likely to occur, so it was made 3.0% or less. Preferably it is 2.2% or less. The lower limit is 0.05%. If it is less than 0.05%, the oxygen concentration in the steel increases and surface defects such as “hegepo” are likely to occur. For further improvement of magnetic properties, Si: more than 0.5% is preferable. More preferably, it is 1.0% or more.
[0019]
Mn:
Mn is an element effective for improving the magnetic properties, but if it exceeds 2.5%, it becomes difficult to control the crystal grain size during magnetic annealing, so it was made 2.5% or less. The lower limit was 0.08%. In order to be less than 0.08%, the time required for refining is remarkably increased, leading to an increase in cost. The upper limit is preferably 2.0%, more preferably 0.1% to 0.5%.
[0020]
S:
On the contrary, the addition of S deteriorates the magnetic properties, so S was made 0.01% or less. Preferably it is 0.005% or less.
[0021]
Acid soluble Al:
Acid-soluble Al is an important element for improving the magnetic properties, but if it exceeds 3.0%, it causes a significant increase in hardness and hinders control of the crystal grain size after magnetic annealing, so it is less than 3.0%. did. Preferably they are 0.0001% or more and 0.05% or less or 0.1% or more and 0.5% or less.
[0022]
P:
P is important for improving the mechanical properties for ensuring the punchability, but if it exceeds 0.1%, it causes breakage during cold rolling, so it was made 0.1% or less. Preferably they are 0.005% or more and 0.02% or less.
[0023]
N:
N is harmful to the magnetic properties and combines with Al to form AlN to refine the crystal grains and cause deterioration of the magnetic properties. Therefore, N is set to 0.0050% or less.
[Si] + [Al] + 0.5 x [Mn]:
Since the relational expression affects the crystal grain size and workability during magnetic annealing, the total amount is specified. It is a combination of elements essential for obtaining coarse crystal grains with good magnetic properties, and Si and Al have the same effect, and Mn has been found to be half of that effect. Therefore, the total amount is a necessary condition for obtaining coarse crystal grains with good magnetic properties.If the total amount is less than 0.1, the effect of improving the magnetic properties is small, and if it exceeds 4.5, the workability is remarkably deteriorated and cracking occurs during bending or drawing. It was 4.5 or less because it occurred. Preferably it is 3.1 or less.
[0024]
In addition, Ni, Cu, Sb, Sn, Ca, Mg, etc. are allowed to be present in a total amount of about 0.5% or less.
In the steel composition according to the present invention, the balance is Fe, but Ti, Nb, Zr, V, W, and the like may be included as inevitable impurities in total of 0.1% or less.
[0025]
The slab having such a steel composition is heated at a temperature of 1300 ° C. or lower and subjected to normal hot rolling. Heating temperature exceeding 1300 ℃ dissolves MnS in steel and causes deterioration of magnetic properties. In order to ensure rollability, the temperature is preferably 1100 ° C to 1250 ° C.
[0026]
After hot rolling, hot-rolled sheet annealing is optionally performed to improve magnetic properties. If the hot-rolled sheet annealing temperature is less than 600 ° C, it is ineffective, and if it exceeds 1100 ° C, the crystal grains become excessively coarse, causing troubles such as fracture during cold rolling. Preferred hot-rolled sheet annealing is performed at 700 to 1000 ° C.
[0027]
The hot-rolled sheet thus obtained is subjected to cold rolling after hot rolling or after hot-rolled sheet annealing. Cold rolling is performed once or by intermediate annealing twice or more to finish to a predetermined thickness.
[0028]
The final annealing is performed at 600 to 1050 ° C. by continuous annealing or batch annealing. If the finish annealing temperature is less than 600 ° C., a sufficient recrystallized structure cannot be obtained, resulting in poor magnetic properties and an increase in hardness. If it exceeds 1050 ° C, the crystal grains become extremely coarse and cracked by bending or drawing during yoke processing. Preferably it is 700-1050 degreeC.
[0029]
After finish annealing, temper rolling with a rolling reduction of 15% or less is performed. Preferably, temper rolling is performed at 0.1% to 15%. Such temper rolling is used for the purpose of removing YPE (yield point elongation) during processing when the component [Si] + [Al] + 0.5 × [Mn] expressed by the formula is 1.0 or more. This is done for the purpose of improving magnetic properties after yoke processing.
[0030]
In the modified example of the present invention, the above-described temper rolling may be performed directly after performing hot-rolled sheet annealing if necessary without performing cold-rolling on the hot-rolled sheet. In such a modified example, since cold rolling and finish annealing can be omitted, a significant reduction in manufacturing cost can be realized, but a slight reduction in magnetic properties is inevitable. However, by adjusting the average surface roughness to Ra: 0.3 μm or more by temper rolling, it is possible to ensure sufficient sound damping properties in this respect.
[0031]
<Crystal grain size>
The soft magnetic steel sheet obtained as described above is subjected to magnetic annealing at, for example, 700 to 950 ° C. when used. In the present invention, the crystal grain size after such heat treatment is set to 30 μm or more and 2.0 mm or less.
[0032]
By the way, if the carrier frequency in the audible range of 1 kHz or more generated by the inverter exceeds 45 dB, the sound becomes extremely unpleasant. Conventionally, it is known that a steel plate with a coarse crystal grain as described in, for example, Japanese Patent Application Laid-Open No. Sho 60-208417 has a poor sound transmission property and an excellent sound damping property. The source of the "external" is to absorb the vibration applied from the outside by using the flow noise of the fluid passing through the welded steel pipe made from steel plate and the noise as a shielding material of the source It is said.
[0033]
On the other hand, the object of the present invention is to suppress the phenomenon that the steel plate itself vibrates due to magnetization, and the vibration is also the multiplication of the fundamental frequency of the magnetizing power source or the multiplication of the inverter carrier. The propagation of vibration generated from the inside strongly depends on the crystal grain size of the steel sheet, and the larger the crystal grain, the worse the propagation property, that is, the better the sound damping property.
[0034]
If the crystal grain size is less than 30 μm, this unpleasant sound exceeds 45 dB and the sound-damping property is poor, and if it exceeds 2.0 mm, cracking occurs during bending, so it is set to 30 μm to 2 mm. Preferably they are 35 micrometers or more and 500 micrometers or less.
[0035]
【Example】
The function and effect of the present invention will be described more specifically with reference to examples.
[Example 1]
After the slab having the chemical composition shown in Table 1 is heated, hot-rolled, pickled, hot-rolled sheet annealed and cold-rolled under the conditions shown in Table 2, the sheet thickness in the table is continuously processed. Temper rolling was performed after recrystallization annealing by annealing or batch annealing.
[0036]
Magnetic evaluation was carried out in accordance with JIS C 2504 magnetic measurement method, after processing a ring test piece having an outer diameter of 45 mm and an inner diameter of 33 mm, magnetic annealing was performed at 800 ° C., and magnetic measurement was performed by direct current.
The sound was evaluated by measuring the sound pressure when excited with 1.0T using a power source with a PWM waveform and a fundamental frequency of 50Hz and a carrier frequency of 1kHz.
[0037]
As shown in Table 2, the formula Si + Al + 0.5Mn, which belongs to the range of the present invention, has a low coercive force, a high magnetic flux density, a crystal grain size of 30 μm or more, and a component range and components, belongs to a predetermined range. The steel plate is suitable for use in a yoke that has a remarkably low sound pressure and is AC magnetized.
[0038]
[Table 1]

[0039]
[Table 2]

[0040]
[Example 2]
In this example, Example 1 was repeated using a slab having a chemical composition shown in Table 3. The results are summarized in Table 4.
[0041]
[Table 3]

[0042]
[Table 4]

[0043]
【The invention's effect】
As described above, according to the present invention, a soft magnetic steel sheet excellent in magnetic properties and sound damping properties can be obtained by defining the steel composition and the crystal grain size after magnetic annealing within a specific range, and in the production thereof. However, normal slab heating, hot rolling, cold rolling, annealing, temper rolling and conventional means may be used, and production can be performed at low cost.

Claims (7)

% By mass
C: 0.01% or less, Si: 0.05% or more and 3.0% or less, Mn: 0.08% or more and 2.5% or less,
S: 0.01% or less, acid-soluble Al: 3.0% or less, P: 0.1% or less,
N: 0.0050% or less,
And 0.1 ≦ [Si] + [Al] + 0.5 × [Mn] ≦ 4.5
Has a steel composition consisting of balance of Fe and unavoidable impurities, the grain size after the magnetic annealing is at 30μm or 2.0mm or less, the average surface roughness Ra: is 0.3μm or more, bending or squeezing processing is given electromagnetic actuator parts soft magnetic steel plate that. % By mass
C: 0.01% or less, Si: more than 0.5%, 3.0% or less, Mn: 0.08% or more, 2.5% or less,
S: 0.01% or less, acid-soluble Al: 3.0% or less, P: 0.1% or less,
N: 0.0050% or less,
And 0.1 ≦ [Si] + [Al] + 0.5 × [Mn] ≦ 4.5
A soft magnetic steel sheet for an electromagnet actuator part which has a steel composition composed of the remaining Fe and inevitable impurities and has a crystal grain size after magnetic annealing of 30 μm or more and 2.0 mm or less, which is subjected to bending or drawing . 2. An excellent sound-damping property in which the sound pressure when the inverter is excited at 1.0 T using a power source with a PWM waveform of a fundamental wave of 50 Hz and a carrier frequency of 1 kHz is used for applications in which AC magnetization is performed by an inverter. Or the soft-magnetic steel plate for electromagnet actuator components of 2. After the slab having the steel composition according to claim 1 or 2 is heated at a temperature of 1300 ° C. or less and hot-rolled, the final sheet thickness is obtained by performing cold rolling once or twice or more with intermediate annealing. The electromagnetic actuator according to any one of claims 1 to 3, wherein continuous annealing or batch annealing is performed at 600 ° C to 1050 ° C, and then temper rolling is performed at a rolling reduction of 15% or less. Manufacturing method of soft magnetic steel sheet for parts . A slab having the steel composition according to claim 1 or 2 is heated at a temperature of 1300 ° C or lower and hot-rolled, and then subjected to hot-rolled sheet annealing at 600 ° C to 1000 ° C, and then cold-rolled once. Or, it is characterized by carrying out intermediate annealing twice or more to obtain the final thickness, then performing continuous annealing or batch annealing at 600 ° C to 1050 ° C, and then performing temper rolling at a rolling reduction of 15% or less. The manufacturing method of the soft-magnetic steel plate for electromagnet actuator components in any one of Claims 1-3. The slab having the steel composition according to claim 1 or 2 is heated at a temperature of 1300 ° C or lower and hot-rolled, and then temper-rolled at a reduction rate of 15% or less. 4. A method for producing a soft magnetic steel sheet for an electromagnet actuator component according to any one of 3 above. The slab having the steel composition according to claim 1 or 2 is heated at a temperature of 1300 ° C or lower and hot-rolled, and then subjected to hot-rolled sheet annealing or finish annealing at 600 ° C to 1000 ° C, and 15% or less. The method for producing a soft magnetic steel sheet for an electromagnetic actuator component according to any one of claims 1 to 3, wherein the temper rolling is performed at a reduction ratio of 5%.