JPH09227997A - High damping alloy and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a material simultaneously excellent in toughness and damping capacity by specifying the componental compsn. of an alloy. SOLUTION: At first, for improving the damping capacity of the allay, suitable amounts of Ti, Nb, Zr and Ta are added. It is aimed to fix C, N and O in the steel drastically damaging the damping capacity as carbide, nitride and oxide, thereby reducing the contents of solid solution C, N and O. Moreover, as elements effective for increasing its strength, suitable amounts of Cu, Ni, Mo, V and B are added thereto. Furthermore, it has been found that, by increasing the (200) diffraction intensity, the magnetization facilitating direction is strengthened to a direction parallel to the surface of the steel sheet to improve its damping capacity. For this purpose, the (200) diffraction intensity ratio is regulated to >=2.5. Moreover, the grain size is preferably regulated to <=100μm for improving its toughness. Furthermore, prescribed rolling and heating are executed for obtaining the above diffraction intensity and grain size.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a damping alloy having a high damping property and a damping alloy having a high toughness as a structural material for ships, bridges, industrial machines and constructions.

[0002]

2. Description of the Related Art Recently, materials for ships, bridges, industrial machines, and buildings tend to be required to have high vibration damping properties in addition to strength and toughness, which are basic characteristics of structural materials. That is, for example, when running on a high-speed railway on a bridge or in large-scale civil engineering,
The present invention aims to solve the problems of suppressing noise and vibration during construction work by the damping effect of the structural material itself and having sufficient toughness as a structural member.

[0003] Conventional iron-based materials used for members intended for damping performance in place of resin sandwich-type damping steel sheets have high hysteresis due to irreversible motion of domain wall motion under the action of alternating stress due to vibration. In order to obtain a vibration-damping property, a material to which Al and Si are added, and
And a material to which is positively added.

As an example of the former, Japanese Patent Laid-Open No. 4-99148
As described in Japanese Patent Publication, the Al content is up to 7.05% and S
There is a ferromagnetic damping alloy with i added up to 4.5%. An example of the latter is a ferromagnetic damping alloy with 8 to 30% of Cr as described in JP-A-52-73118. There are vibration alloys.

Further, in JP-A-6-220583 and JP-A-5-302148, there is disclosed a ferromagnetic damping alloy in which Mn is 0.1 or 0.2% or less and 1 to 5% of Cr is added. is there. In addition, the inventors of the present invention filed Japanese Patent Application No. 6-2589.
No. 82 proposed a ferromagnetic damping alloy in which Mn is added in an amount of 0.2 to 2.5% and Cr is added in an amount of 1 to 5%.

In Japanese Unexamined Patent Publication No. 7-298313, the inventors have proposed a pure iron damping alloy having C of 0.01% or less and N of 0.006% or less. Also, Ryohei Tanaka, damping material (its function and application), published by Kousendo March 1992, p192.
No. 197, it is described that, as a ferromagnetic alloy, external stress causes the domain wall to move, and the vibration energy is absorbed by the resulting hysteresis loss.

[0007]

However, among these alloys, the alloy described in Japanese Patent Application Laid-Open No. 4-99148 has an inappropriate upper limit regulation of Al and Si addition amounts. This leads to the formation of a product, which acts as the point of origin of fracture, resulting in a decrease in toughness. Also,
Since the alloy described in JP-A-52-73118 has excessive Cr addition, the toughness of Cr-based inclusions is reduced as in the above case.

Further, in JP-A-6-220583 and JP-A-5-302148, the toughness is low because no aggressive measures for improving the toughness are taken. In addition, Japanese Patent Application Hei 6
No. 258982 has insufficient toughness because it has priority on securing toughness. In Japanese Patent Laid-Open No. 7-298313,
Since the regulations on the amounts of C and N are strict, the cost is increased. The literature on damping materials describes the mechanism of damping alloys, and does not describe any measures for improving the damping alloys, specific component systems / manufacturing methods, or methods for simultaneously satisfying toughness in addition to damping properties. An object of the present invention is to provide a high-strength damping alloy having excellent damping properties and damping properties and high toughness.

[0009]

The gist of the present invention is as follows. (1) Weight%, C: 0.20% or less, Si: 0.01
% Or more and 3.5% or less, Mn: 2.5% or less, P: 0.
010% or less, S: 0.005% or less, Cr: 3.5%
Hereinafter, Al: 0.002% or more, 3.5% or less, N:
0.010% or less is contained, Ti: 0.5% or less, Nb: 0.5% or less, Zr: 0.5% or less, Ta:
A damping alloy containing 0.5% or less of one or more kinds, and the balance being Fe and unavoidable impurities.

(2) Cu: 0.05-2.5 by weight%
%, Ni: 0.05-2.5%, Mo: 0.05-4.
5%, Nb: 0.005 to 0.2%, V: 0.005 to
0.2%, Ti: 0.005 to 0.1%, B: 0.00
The vibration damping alloy according to (1), which contains at least one of 03 to 0.005%.

(3) Ca: 0.001 to 0.
The vibration damping alloy according to (1) or (2), which contains at least one of 0.05% and REM: 0.001 to 0.1%. (4) The vibration damping alloy according to any one of (1) to (3), which has a (200) diffraction intensity ratio of 2.5 or more. (5) The damping alloy according to any one of (1) to (4), which ensures high toughness by setting the crystal grain size to 100 μm or less.

(6) The heating temperature is 1000 to 1250 ° C.,
After hot rolling at a rolling reduction temperature of 900 ° C or lower at 30 to 70% and a rolling finishing temperature of 800 ° C or lower, it is cooled to room temperature,
The method for producing a vibration damping alloy according to any one of (1) to (5), characterized by performing a tempering or an annealing heat treatment at 950 ° C. (7) The method for producing a vibration-damping alloy according to (6), characterized in that hot rolling is performed so that the rolling finishing temperature is in the range of 650 to 800 ° C.

[0013]

The present invention has been made in view of the above circumstances, and in order to obtain high damping characteristics due to hysteresis due to non-reciprocal motion of domain wall movement under the action of alternating stress due to vibration, It is based on components that have reduced the elements that cause the formation of various harmful elements, inclusions, and precipitates, impede domain wall movement, and greatly impair vibration damping. However, reducing the amount of C, N, and O to the limit, as has been conventionally done, causes a significant cost increase.

Therefore, Ti, N are used as elements for fixing the elements dissolved in these steels in the form of precipitates and rendering them harmless.
b, Zr and Ta were found. By adding an appropriate amount of these elements, the vibration damping property is significantly improved. That is, T
By adding i, Nb, Zr, and Ta, the regulation of the amounts of C, N, and O is relaxed for the equivalent vibration damping property.
Cost reduction can be achieved, and C, N, O is required for the equal cost, that is, the regulation of the equal amount of C, N, O.
Since the harmfulness of can be reduced, the vibration damping property is greatly improved.

Further, in the past, since the crystal grain boundary hinders the domain wall movement, the vibration damping property was improved only by coarsening the grain. However, as a result of various studies by the inventors, the vibration damping by the coarsening has been performed. As an alternative to the method for improving the vibration resistance, it has been found that the vibration damping property is significantly improved by increasing the (200) diffraction intensity. By increasing the (200) diffraction intensity, the <100> orientation parallel to the steel sheet surface is strengthened.

That is, the easy magnetization direction is strengthened in the direction parallel to the steel plate surface. It is a new discovery that the damping property is improved by strengthening the easy magnetization direction. This (200)
It was found that the vibration damping property is improved by setting the diffraction intensity ratio to 2.5 or more.

When the (200) diffraction intensity ratio is 2.5 or more, the loss coefficient, which is an index of vibration damping property, can be secured to be 0.02 or more. From the viewpoint of vibration damping performance, (200)
The higher the diffraction intensity ratio, the better, but practically (200) the diffraction intensity ratio is preferably in the range of 2.5 to 12.0 in consideration of other steel properties such as toughness, resulting in 0.02.
It is preferable to ensure a loss factor of ~ 0.05.

Here, the (200) diffraction intensity ratio is (200) at a quarter thickness position in the plate thickness direction by X-ray diffraction.
The diffraction intensity was measured and the ratio to the (200) diffraction intensity of the random sample material in which the specific orientation was not strengthened or controlled was determined. This time, the plate surface, 1/2 thickness and 1/4 thickness direction
As a result of examining the thickness, the maximum value of the (200) diffraction intensity ratio was about 15.

In order to increase the (200) diffraction intensity ratio, it is necessary to carry out low temperature rolling.
This can be achieved by setting the rolling reduction at 0 ° C. or less to 30% or more. Therefore, the rolling finishing temperature is 850 ° C. or lower.

Next, in order to improve the toughness, the crystal grain size is set to 10
It is necessary to make it 0 μm or less. When the rolling finishing temperature is lower than 650 ° C. in the manufacturing method for setting the (200) diffraction intensity ratio to 2.5 or higher, the crystal grain size may exceed 100 μ, so the rolling finishing temperature is set to 650 ° C. or higher.

After hot rolling, tempering or annealing heat treatment is necessary in order to increase the (200) diffraction intensity ratio and reduce the strain introduced into the steel sheet by rolling. Since the diffraction intensity ratio becomes low, the upper limit temperature is 950 ° C.

Next, the reasons for limitation of the present invention will be described. C acts as an obstacle to the movement of the domain wall even if it is in a solid solution state or is precipitated as a carbide, and lowers the vibration damping property.

Since Si is important as a deoxidizing material,
It is necessary to add it in an amount of not less than 01%, but the cost increases by adding it, so it is preferable to limit it to less than 0.5% as an inexpensive general-purpose material that does not particularly require high strength (for example, 400 MPa or more). . However, it is an effective element for increasing the strength, and apart from the cost, 0.5% or more may be added to obtain a steel material requiring high strength of 400 MPa or more. It is preferable not to increase the strength but to adjust it in consideration of the addition amount of other strength increasing elements (Mn, Al, Cu). In this case as well, if the addition exceeds 3.5%, the vibration damping property deteriorates, so the upper limit of the Si content is made 3.5%.

Mn is a solid solution strengthening element, has no effect on improving vibration damping property and toughness, and increases the cost by adding it. Therefore, in the case of an inexpensive general-purpose material that does not require high strength, 0.2 Most preferably it is limited to less than%. However, it is an effective element for increasing the strength when a high strength of 400 MPa or more is required, and for this purpose, 0.
You may add 2% or more. However, if it is added in excess of 2.5%, the damping property will decrease, so the upper limit of the Mn content is 2.5%.

P and S form non-metallic inclusions in the steel, and segregate to hinder the movement of the domain wall to reduce the vibration damping property. Therefore, P is set to 0.010% or less and S is set to 0.005% or less.

Similar to Si and Mn, Al is an important element as a deoxidizing material, and is an important element for improving vibration damping property and strength. It is necessary to secure at least 0.002%, but the addition of this will increase the cost, so especially high strength of 400
In the case of inexpensive general-purpose damping steel materials that do not require MPa or more,
Most preferably, it is limited to less than 0.1%. However, 4
It is an effective element for increasing the strength when a high strength of 00 MPa or more is required.
You may add 1% or more.

However, it is preferable to adjust the strength according to the required strength (final ultimate strength of 400 MPa to 500 MPa) in combination with the addition amount of other strength increasing elements such as Si, Cr and Mn. Even in this case,
The upper limit of the amount of Al is 3.5% because if it exceeds 3.5% irrespective of the amount of addition of other strength-increasing elements such as Si, Cr, and Mn, the damping property decreases.

Cr is a ferrite former, which is an element that coarsens the crystal grains when added, and slightly improves the vibration damping property, but it is an expensive element and it is preferable to reduce the added amount as much as possible. Therefore, especially high strength 400
In the case of inexpensive general-purpose damping steel materials that do not require MPa or more,
Most preferably, the upper limit is limited to less than 0.5%. However, it is an effective element for increasing strength, and 400 MPa
For the purpose of ensuring the above strength, 0.5% or more may be added.

However, it is preferable to adjust the amount of Cr added according to the ultimate strength (400 MPa or 500 MPa) in combination with the amount of other strength increasing elements such as Si, Al and Mn. Even if other strength-increasing elements such as Si, Al, and Mn are not added, if they are added in excess of 3.5%, the damping property will decrease. Therefore, the upper limit of the Cr content is 3.5%.

N, which acts as an obstacle to the movement of the domain wall even if it is in a solid solution state or precipitates as a nitride, lowers the vibration damping property, so that it is preferably as low as possible, and the upper limit is made 0.010%.

The greatest point of the present invention is Ti, N
b, Zr, and Ta fix C, N, and O in the steel as carbides, nitrides, and oxides, reduce the amount of solute C, N, and O and improve the vibration damping property. %, But if the content exceeds 0.5%, the effect due to the above-mentioned action saturates and at the same time, the toughness is impaired, so the upper limit is made 0.5%.

Further, Cu, N added as necessary
i, Mo, V, and B are elements effective in increasing strength, and when combined with other Al, Si, Mn, Cr, etc., 40
The above amount was set as the lower limit as a range in which the strength of 0 MPa or 500 MPa or more could be obtained and the effect was not insufficient, and the above amount was set as the upper limit as the range in which the damping property and the toughness were not deteriorated.

Further, Ca, R added as necessary
EM is an element effective in improving toughness, and the above amount was set as the lower limit as a range in which the effect was not insufficient, and the above amount was set as the upper limit as a range in which the toughness and vibration damping were not deteriorated.

Regarding the manufacturing conditions, the heating temperature is 1250 ° C. or lower in order to make the heated austenite grains fine and the (200) diffraction intensity ratio high, and further 1000 ° C. or higher in order to eliminate the temperature deviation in the steel sheet during heating. And

Regarding the rolling conditions, in order to raise the (200) diffraction intensity ratio, a reduction rate of 30% or more is required at 900 ° C. or lower, but if the reduction rate exceeds 70%, the load on the rolling mill becomes large. Also, the rolling time becomes long and this causes a cost increase, so the upper limit is made 70%.

Since the rolling finish temperature is 900 ° C. or lower and 30% or more of rolling is performed, the rolling finish temperature is 800 ° C. or lower, but if it is lower than 650 ° C., rolling in the ferrite region may occur and the grain size may exceed 100 μ, resulting in a decrease in toughness. Therefore, the lower limit is set to 650 ° C.

After hot rolling and cooling to room temperature, (20
0) In order to further improve the diffraction intensity ratio and reduce the strain introduced into the steel sheet by rolling, tempering or annealing heat treatment is required, and heat treatment at 650 ° C. or higher is performed, but the (200) diffraction intensity ratio is The upper limit temperature is set to 950 ° C., because heat treatment weakens it at high temperatures.

[0038]

[Examples] First, a matchmaking alloy having the composition range shown in Table 1 was prepared, and a plate-shaped test piece having an original thickness of 40 mm width and a length of 400 mm was processed from this, and the vibration damping property was measured by a mechanical impedance method. It was Among the alloys shown in Table 1, Steels A to I are alloys within the composition range of the present invention, and Steels J to R are alloys outside the composition range of the present invention. The various properties of these steels produced under the production conditions shown in Table 2 are also shown in the table. Each steel sheet having a thickness of 6 mm or more was hot-rolled, cooled to room temperature, and then heat-treated. A sheet having a thickness less than that was hot-rolled, wound, and then heat-treated.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

Examples 1 to 10 are examples of the present invention, and Examples 11 and 2
2 is a comparative example. Examples 1-7 and 11-18 have a plate thickness of 25 m
m, Example 8 has a plate thickness of 2.5 mm, Examples 9 and 10 have a plate thickness of 50 mm, and Examples 19 to 22 have a plate thickness of 40 mm.

The inventive example of Example 1 has a (200) diffraction intensity ratio of 2.5 or more, high intensity (≧ 400 MPa), and high vibration damping performance (η ≧ 0.02). In Examples 2 to 10, the rolling finishing temperature was 650 ° C or higher and the (200) diffraction intensity ratio was 2.
5 or more, the crystal grain size is 100 μ or less, and high strength (≧
It has high vibration damping performance (η ≧ 0.02) and high toughness (≧ 50J) at 400 MPa.

Since Examples 3 to 8 contain the selective element effective for increasing the strength, the strength is higher (≧ 500 MPa), and
No. 10 has a higher toughness (≧ 80 J) because it contains a selective element effective for increasing the toughness.

Comparative Example 11 had a (200) diffraction intensity ratio of 2.
Although it is 5 or more, the crystal grain size is more than 100 μ, the C is high, and the vibration damping performance and the toughness are low. Example 12 has a (200) diffraction intensity ratio of 2.5 or more and a crystal grain size of 100 μm or less,
Is high and the damping performance is low. Example 13 has a (200) diffraction intensity ratio of 2.5 or more and a crystal grain size of 100 μ or less,
High Mn and low vibration damping performance.

In Examples 14 and 15, the (200) diffraction intensity ratio was 2.5 or more and the crystal grain size was 100 μ or less.
No. 4 has a high P and Example 15 has a high S, and the vibration damping performance is low. In Example 16, the (200) diffraction intensity ratio is 2.5 or more and the crystal grain size is 100 μ or less, but Cr is high and the toughness is low. In Example 17, the (200) diffraction intensity ratio is 2.5 or more and the crystal grain size is 100 μ or less, but Al is high and the toughness is low.

In Example 18, the (200) diffraction intensity ratio is 2.5 or more and the crystal grain size is 100 μ or less, but N is high and the vibration damping performance is low. Since Example 19 does not contain an element that fixes C, N and O, the vibration damping performance is low. Example 20 has a low rolling reduction of 900 ° C. or lower, a low (200) diffraction intensity ratio, a crystal grain size of more than 100 μ, and low vibration damping performance and toughness.

In Example 21, the heat treatment temperature is low, the (200) diffraction intensity ratio is low, and the crystal grain size is 100 μm or less, but the vibration damping performance is low. Example 22 had a high heat treatment temperature, (200)
The diffraction intensity ratio is low and the crystal grain size is 100 μm or less,
Vibration control performance is low.

[0049]

According to the present invention, ships, bridges, industrial machines,
Supply of structural materials for construction becomes possible, and the effect on the industrial world is extremely large.

Claims (7)

[Claims] 1. By weight%, C: 0.20% or less, Si: 0.01% or more, 3.5% or less, Mn: 2.5% or less, P: 0.010% or less, S: 0 0.005% or less, Cr: 3.5% or less, Al: 0.002% or more, 3.5% or less, N: 0.010% or less, and further Ti: 0.005-0.5% , Nb: 0.005-0.5%, Zr: 0.005-0.5%, Ta: 0.005-0.5%, and at least one of Fe and unavoidable impurities. Damping alloy characterized by. 2. By weight%, Cu: 0.05 to 2.5%, Ni: 0.05 to 2.5%, Mo: 0.05 to 4.5%, V: 0.005 to 0. 2%, B: 0.0003-0.005% At least 1 sort (s) or more are contained, The damping alloy of Claim 1 characterized by the above-mentioned. 3. At least one of Ca: 0.001 to 0.05% and REM: 0.001 to 0.1% by weight is contained. Damping alloy. 4. The vibration damping alloy according to claim 1, wherein the (200) diffraction intensity ratio is 2.5 or more. 5. The damping alloy according to claim 1, wherein a high toughness is ensured by setting the crystal grain size to 100 μm or less. 6. A heating temperature of 1000 to 1250 ° C., 90
The rolling reduction at 0 ° C or lower is 30 to 70%, and the rolling finishing temperature is 80.
After hot rolling at 0 ° C or lower, it is cooled to room temperature and then 650-95.
The method for producing a vibration damping alloy according to claim 1, wherein tempering or annealing heat treatment is performed at 0 ° C. 7. A rolling finishing temperature range of 650 to 800 ° C.
The method for producing a vibration-damping alloy according to claim 6, wherein hot rolling is performed.