JPH09143622A - Damping alloy and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a damping alloy for a structural material simultaneously excellent in toughness and damping capacity by specifying the componental compsn. of an alloy and producing conditions therefor and increasing the (200) diffraction intensity. SOLUTION: This damping alloy has a compsn. contg., by weight, <=0.02% C, 0.5 to 3.5% Si, <0.2% or 0.2 to 2.5% Mn, <=0.010% P, <=0.005% S, 0.5 to 3.5% Cr, >0.060 to 3.5% Al and <=0.006% N, and the balance Fe, and in which the (200) diffraction intensity ratio is regulated to >=3.5 and the grain size to <=120μm. By increasing the (200) diffraction intensity, the <100> orientation in the direction parallel to the surface of the steel plate is strengthened to improve its damping capacity. For obtaining the alloy, a slab is heated at 1000 to 1200 deg.C heating temp., is subjected to hot rolling in such a manner that the rolling ratio at <=970 deg.C is regulated to >=70% and the rolling finishing temp. is regulated to <=870 deg.C (720 to 870 deg.C), and furthermore, subjects to hot rolling in a range from the Ar1 +50 deg.C to the Ar1 +100 deg.C, is subsequently cooled to room temp. and is subjected to tempering or annealing heat treatment at 660 to 960 deg.C. Moreover, the above compsn. may be incorporated with prescribed amounts of Cu, Ni, Mo, Nb, V, Ti, B, Ca and rare earth metals.

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 at the same time to have high vibration damping properties in addition to the basic characteristics of structural materials such as strength and toughness. That is, for example, the problem of suppressing noise and vibration during high-speed railway running on a bridge, large-scale civil engineering, and construction work by the damping effect of the structural material itself and having sufficient toughness as a structural member Is.

Conventional iron-based materials used as members for the purpose of damping property instead of resin sandwich type damping steel plate are high in hysteresis due to irreversible motion of domain wall movement under the action of alternating stress due to vibration. In order to obtain damping characteristics, it is divided into two types: a material to which Al and Si are added and a material to which Cr is positively added, with the aim of adding a ferrite former to make the structure into a ferrite single phase. An example of the former is a ferromagnetic alloy in which Al is added up to 7.05% and Si is added up to 4.5% as described in JP-A-4-99148. Sho 5
There is a ferromagnetic damping alloy in which 8 to 30% of Cr is added, as described in Japanese Patent Laid-Open No. 2-73118.

Further, there is a ferromagnetic damping alloy containing Mn of 0.1 or 0.2% or less and Cr of 1 to 5% in JP-A-6-220583 and JP-A-5-302148. . In addition, the present inventors have filed Japanese Patent Application No. 6-258982.
Proposed a ferromagnetic damping alloy containing 0.2 to 2.5% of Mn and 1 to 5% of Cr. In addition, Ryohei Tanaka, Vibration damping material "its function and application", Kosaido, March 1992, P. 1
It is described in 92 to 197 that, as a ferromagnetic alloy, external stress causes the domain wall to move, and the resulting hysteresis loss absorbs vibration energy.

[0005]

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 substance, which acts as a point of fracture occurrence, resulting in a decrease in toughness. Further, since the alloy described in JP-A-52-73118 is excessively Cr-added, the toughness is lowered by the Cr-based inclusions similarly to the above.

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 No. 6-
No. 258982 is insufficient in terms of vibration damping because it prioritizes securing toughness. Further, in the literature of damping materials, the mechanism of damping alloy is written, and there is no description about the improvement measures, 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 damping alloy having excellent damping properties and damping properties and high toughness.

[0007]

The gist of the present invention is as follows. (1) C: 0.02% or less by weight%, Si: 0.5
% Or more and 3.5% or less, Mn: less than 0.2%, P: 0.
010% or less, S: 0.005% or less, Cr: 0.5%
Above, 3.5% or less, Al: over 0.060%, 3.5%
Hereafter, N: 0.006% or less is contained, the balance is Fe and unavoidable impurities, and the (200) diffraction intensity ratio is 3.5.
The above is a damping alloy characterized by the above.

(2) C: 0.02% or less by weight%,
Si: 0.5% or more, 3.5% or less, Mn: 0.2% or more, 2.5% or less, P: 0.010% or less, S: 0.0
05% or less, Cr: 0.5% or more, 3.5% or less, A
1: more than 0.060%, 3.5% or less, N: 0.006%
Contains the following, with the balance Fe and unavoidable impurities,
(200) A vibration damping alloy having a diffraction intensity ratio of 3.5 or more.

(3) Cu: 0.05-2.
5%, Ni: 0.05 to 2.5%, Mo: 0.05 to
4.5%, Nb: 0.005-0.2%, V: 0.00
5 to 0.2%, Ti: 0.005 to 0.1%, B: 0.
The vibration damping alloy according to (1) or (2), characterized in that it contains 0003 to 0.005% by one kind or two or more kinds.

(4) Ca: 0.001 to 1% by weight
0.05% and REM: 0.001-0.1% are contained 1 type or 2 types, The damping alloy in any one of (1)-(3) characterized by the above-mentioned. (5) The damping alloy according to any one of (1) to (4), characterized in that high toughness is ensured by setting the crystal grain size to 120 μm or less.

(6) The heating temperature is 1000 to 1200.
670 ° C., 970 ° C. or lower, 70% or more, rolling finishing temperature: 870 ° C. or less, hot rolling, then cooling to room temperature, 660
The method for producing a vibration-damping alloy according to any one of (1) to (5), which comprises performing a tempering or an annealing heat treatment at ˜960 ° C. (7) The method for producing a vibration-damping alloy according to (6), characterized in that hot rolling is performed with a rolling finishing temperature range of 720 to 870 ° C. (8) Rolling finishing temperature range is Ar ₁ + 50 ° C. to Ar ₁
The method for producing a vibration damping alloy according to (6) or (7), characterized in that hot rolling at + 100 ° C. is performed.

[0012]

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 irreversible motion of domain wall movement under the action of alternating stress due to vibration, the It is based on pure iron-based components in which the elements that cause harmful harmful elements, inclusions, and precipitates, interfere with domain wall movement, and greatly impair vibration damping are minimized.

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, but 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 direction of easy magnetization is strengthened in a direction parallel to the steel sheet surface. It is a new discovery that the damping property is improved by strengthening the easy magnetization direction.

Then, this (200) diffraction intensity ratio is set to 3.
It was found that the vibration damping property is improved by setting it to 5 or more. When the (200) diffraction intensity ratio is 3.5 or more, the loss coefficient, which is an index of vibration damping property, can be secured at 0.035 or more. From the viewpoint of vibration damping performance, the (200) diffraction intensity ratio is high. Moderately good, but in consideration of other steel properties such as toughness, the practical (200) diffraction intensity ratio is 3.5 to 13.
0 range is preferred, resulting in 0.035-0.
It is preferable to ensure a loss factor of 06.

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. As a result of this study, 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, and as a result of examination, 970
It can be achieved by setting the rolling reduction at 70 ° C or lower to 70% or higher.
Therefore, the rolling finishing temperature is 870 ° C. or lower. Furthermore,
As a result of a detailed study for improving the vibration damping property, by setting the rolling finishing temperature to Ar ₁ + 50 ° C. to Ar ₁ + 100 ° C., (2
It has been found that the 00) diffraction intensity ratio is further improved and the vibration damping property is further improved.

Further, when a high strength of 420 MPa or more is required, Mn was found as an element capable of significantly increasing the strength without impairing the vibration damping property and the toughness. By adding 0.2% or more of Mn, both the vibration damping property of loss factor (= η) of 0.035 or more and the strength of 420 MPa or more, or the loss factor (= η) of 0.035.
It is possible to satisfy all of the above vibration damping properties, the strength of 420 MPa or more, and the high toughness of the absorbed energy at 0 ° C. in the V notch Charpy impact test of 80 J or more.

Next, in order to improve the toughness, the crystal grain size is set to 12
It is necessary to make it 0 μm or less. In the manufacturing method for setting the (200) diffraction intensity ratio to 3.5 or more, if the rolling finishing temperature is lower than 720 ° C., the crystal grain size may exceed 120 μ, so the rolling finishing temperature is set to 720 ° 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. Is lower, the upper limit temperature is 9
60 ° C.

As described above, the damping property is improved by introducing the texture even in the fine grain structure, and further improvement of the damping property was examined. As a result, it was found that by adding the ferrite formers Si, Al, and Cr, some coarse grains were achieved in the process of strain relief heat treatment after hot rolling, and the vibration damping property was further improved. The strength is also increased by adding Si, Al and Cr.

Next, the reasons for limitation of the present invention will be described. C
Is not preferable because it acts as an obstacle to domain wall movement even if it is in a solid solution state or is precipitated as a carbide, and reduces the vibration damping property. Therefore, the upper limit is 0.02%.

Si is important as a deoxidizing material,
Since it is an important ferrite former and solid solution strengthening element, it is indispensable for improving the vibration damping property, and 0.5% or more must be added. On the other hand, if added over 3.5%, SiO
_It induces the formation of inclusions such as ₂ and acts as the point of fracture occurrence, which significantly reduces toughness. Therefore, the addition range of Si is 0.5% or more and 3.5% or less.

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, Mn is less than 0.2% unless high strength of 420 MPa or more is required. It is good to limit to However,
Especially when a high strength of 420 MPa or more is required, Mn is an essential element for ensuring the strength, and for this purpose, it is necessary to add 0.2% or more, but more than 2.5%. Since the vibration damping property will be deteriorated when added as Mn, the upper limit of the amount of Mn is 2.5%.

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

Al is important as a deoxidizing material,
Since it is an important ferrite former, it is indispensable for improving the vibration damping property, and it is necessary to add more than 0.060%. On the other hand, if it is added in excess of 3.5%, inclusions such as Al ₂ O ₃ are generated, which acts as a point of occurrence of fracture, resulting in a significant decrease in toughness. Therefore, the addition range of Al is 0.06
It is more than 0% and 3.5% or less.

Cr is a ferrite former, and is an element that causes the crystal grains to become slightly coarse when added.
0.50% or more is added to improve the vibration damping property, but at the same time, toughness is reduced, and it is preferable to reduce the added amount as much as possible because it is an expensive element. Therefore, the upper limit is 3.5%.
Restrict to the following. N 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 nitride, and lowers the vibration damping property, so that it is preferably as low as possible, and the upper limit is made 0.006%.

Further, Cu, N added as necessary
i, Mo, Nb, V, Ti, and B are elements effective for increasing strength, and the above amount is set as the lower limit as a range in which the effect is not insufficient, and as a range in which vibration damping and toughness are not deteriorated. The upper limit was the amount. Further, Ca and REM added as necessary are elements effective for improving the toughness, and the above amount is set as the lower limit as a range in which the effect is not insufficient, and a range in which the toughness rather decreases and the vibration damping property does not decrease. As
The above amount was made the upper limit.

Regarding the manufacturing conditions, the heating temperature is 1200 ° 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 increase the (200) diffraction intensity ratio,
70% or more rolling is required at 970 ° C or less.

The rolling finishing temperature is 870 ° C. or lower because the rolling finish temperature is 970 ° C. or lower and 70% or more of rolling is performed.
If it is less than 2,000, the ferrite region is rolled, and the crystal grain size may exceed 120 μ, and the toughness decreases, so the lower limit is 720 ° C.
And Furthermore, the rolling finishing temperature is Ar ₁ + 50 ° C. to Ar ₁
By setting the temperature to + 100 ° C., the (200) diffraction intensity ratio is further improved and the vibration damping characteristics are further improved.

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 660 ° C. or higher is performed, but the (200) diffraction intensity ratio is The upper limit temperature is set to 960 ° C., because heat treatment weakens it at high temperature.

[0030]

Example First, a matchmaking alloy having the composition range shown in Table 1 was prepared, and a plate-like 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 the mechanical impedance method. Among the alloys shown in Table 1, Steel Nos. A to F are alloys within the composition range of the present invention, and Steels Nos. G to P are alloys outside the composition range of the present invention. Table 2 also shows various characteristics of these steels manufactured under the manufacturing conditions shown in Table 2. Each steel sheet having a thickness of 6 mm or more was heat-rolled, then cooled to room temperature and then heat-treated. A sheet having a thickness less than that was hot-rolled, wound, and then heat-treated.

[0031]

[Table 1]

[0032]

[Table 2]

Examples 1 to 7 are examples of the present invention, and Examples 8 to 21 are comparative examples. Examples 1-4 and 8-14 have a plate thickness of 24 mm, Example 5
Has a plate thickness of 1.8 mm, Examples 6 to 7 have a plate thickness of 32 mm, Examples 15 to 21
Is a plate thickness of 16 mm. The example of the present invention of Example 1 has a (200) diffraction intensity ratio of 3.5 or more and high vibration damping performance (η ≧ 0.03).
5) and the strength is 378 due to less than 0.2% Mn.
It remains at MPa. Examples 2 to 7 have a rolling finish temperature of 7
At 20 ° C or higher, (200) diffraction intensity ratio of 3.5 or higher,
Since the crystal grain size is 120 μ or less and Mn is added by 0.2% or more, it has high strength (≧ 420 MPa), high vibration damping performance (η ≧ 0.035) and high toughness (≧ 80 J). .

Since Examples 4 and 5 contain a selective element effective for increasing the strength, the strength is higher (≧ 450 MPa), and Examples 6 and 7 contain a selective element effective for increasing the toughness.
Further, it has high toughness (≧ 100 J).

Comparative Example 8 has a (200) diffraction intensity ratio of 3.5.
However, the crystal grain size exceeds 120 μm, the C content is high, and the vibration damping performance and toughness are low. Example 9 has a (200) diffraction intensity ratio of 3.5.
As described above, although the crystal grain size is 120 μ or less, Si is low and strength and vibration damping performance are low. In Example 10, the (200) diffraction intensity ratio is 3.5 or more and the crystal grain size is 120 μ or less, but Si is high and the vibration damping performance is low. Examples 11 and 12 are (2
00) The diffraction intensity ratio is 3.5 or more, and the crystal grain size is 120μ.
As follows, Example 11 has a high P, Example 12 has a high S,
Vibration control performance is low.

In Example 13, the (200) diffraction intensity ratio is 3.5 or more and the crystal grain size is 120 μ or less, but Cr is low,
Low strength and vibration damping performance. In Example 14, the (200) diffraction intensity ratio is 3.5 or more and the crystal grain size is 120 μ or less, but C
r is high and toughness is low. Example 15 has a (200) diffraction intensity ratio of 3.5 or more and a crystal grain size of 120 μ or less.
1 is low, strength and vibration damping performance are low.

In Example 16, the (200) diffraction intensity ratio is 3.5 or more and the crystal grain size is 120 μ or less, but Al is high,
Low toughness. In Example 17, the (200) diffraction intensity ratio is 3.5 or more and the crystal grain size is 120 μ or less, but N is high and the vibration damping performance is low. Example 18 has a high heating temperature, and Example 19 has 97
The rolling reduction at 0 ° C. or lower is low, the (200) diffraction intensity ratio is low, the crystal grain size is more than 120 μm, and the vibration damping performance and toughness are low.

In Example 20, the heat treatment temperature is low, the (200) diffraction intensity ratio is low, and the crystal grain size is 120 μ or less, but the vibration damping performance is low. Example 21 has a high heat treatment temperature (200)
The diffraction intensity ratio is low and the crystal grain size is 120μ or less,
Vibration control performance is low.

Next, various characteristics of the steels P, Q, and R of the alloys in the composition range of the present invention shown in Table 3 are shown together with those produced under the production conditions of the present invention shown in Table 4. Examples 1, 2,
No. 3 is an example in which the rolling finishing temperature is in a more desirable range.
The plate thickness is all 24 mm. Ar ₁ of the steels P, Q and R are 735 ° C., 740 ° C. and 730 ° C., respectively.

In Examples 1, 2, and 3, the rolling finishing temperature was Ar ₁ +5.
Within the range of 0 ° C. to Ar ₁ -20 ° C., the (200) diffraction intensity ratio is 5.0 or more, and further excellent vibration damping performance (η ≧ 0.
045) and the rolling finishing temperature is Ar ₁ + 50 ° C. to Ar.
_It has better vibration damping performance than Examples 4 to 6, which are not in the range of ₁ + 100 ° C.

[0041]

[Table 3]

[0042]

[Table 4]

[0043]

EFFECTS OF THE INVENTION According to the present invention, it is possible to supply ships, bridges, industrial machines, structural materials for construction where vibration damping performance is required, and characteristics such as toughness or strength and vibration damping performance are required at the same time. Therefore, the effect on the industry is extremely large.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C22C 38/58 C22C 38/58

Claims (8)

[Claims] 1. By weight%, C: 0.02% or less, Si: 0.5% or more, 3.5% or less, Mn: less than 0.2%, P: 0.010% or less, S: 0 0.005% or less, Cr: 0.5% or more, 3.5% or less, Al: more than 0.060%, 3.5% or less, N: 0.006% or less, the balance Fe and unavoidable impurities A damping alloy having a (200) diffraction intensity ratio of 3.5 or more. 2. By weight%, C: 0.02% or less, Si: 0.5% or more, 3.5% or less, Mn: 0.2% or more, 2.5% or less, P: 0.010. % Or less, S: 0.005% or less, Cr: 0.5% or more, 3.5% or less, Al: more than 0.060%, 3.5% or less, N: 0.006% or less, A vibration-damping alloy comprising the balance Fe and unavoidable impurities and having a (200) diffraction intensity ratio of 3.5 or more. 3. By weight%, Cu: 0.05 to 2.5%, Ni: 0.05 to 2.5%, Mo: 0.05 to 4.5%, Nb: 0.005 to 0. 2%, V: 0.005-0.2%, Ti: 0.005-0.1%, B: 0.0003-0.005%, 1 type (s) or 2 or more types are contained, It is characterized by the above-mentioned. The vibration damping alloy according to item 1 or 2. 4. The composition according to any one of claims 1 to 3, wherein the content of Ca is 0.001 to 0.05%, and REM is 0.001 to 0.1% by weight. Damping alloy described in Crab. 5. The vibration damping alloy according to claim 1, wherein a high toughness is ensured by setting the crystal grain size to 120 μm or less. 6. A heating temperature of 1000 to 1200 ° C., 97
The rolling reduction temperature of 0 ° C or less is 70% or more, and the rolling finishing temperature is 870.
After hot rolling at ℃ or less, cool to room temperature, 660-960
The method for producing a vibration damping alloy according to any one of claims 1 to 5, characterized by performing a tempering or an annealing heat treatment at a temperature of ° C. 7. The rolling finishing temperature range is 720 to 870 ° C.
The method for producing a vibration-damping alloy according to claim 6, wherein hot rolling is performed. 8. The rolling finishing temperature range is Ar ₁ + 50 ° C.
The method for producing a vibration damping alloy according to claim 6, wherein hot rolling at Ar ₁ + 100 ° C. is performed.