JPH08209292A - High strength and high toughness damping alloy - Google Patents

Abstract

PURPOSE: To produce a damping alloy for a structural material simultaneously excellent in strength, toughness and damping capacity. CONSTITUTION: This high strength and high toughness damping alloy is the one contg., by weight, <=0.02% C, 0.5 to 3% Si, 0.2 to 2.5% Mn, <1% Cr, 0.005 to 5% Al, and the balance Fe with inevitable impurities. It is preferable that it furthermore contains one or >= two kinds among 0.02 to 0.2% P, 0.05 to 2.5% Cu, 0.05 to 2.5% Ni, 0.05 to 4.5% Mo, 0.005 to 0.2% Nb, 0.005 to 0.2% V, 0.005 to 0.1% Ti and 0.0003 to 0.005% B, contains 0.0045 to 0.015% N and contains one or two kinds of 0.001 to 0.05% Ca and 0.001 to 0.1% rare earth metals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping alloy that satisfies the strength and toughness requirements of a structural material for ships, bridges, industrial machines and constructions and has high damping properties.

[0002]

2. Description of the Related Art Ships, bridges, industrial machines and buildings tend to be required to have high vibration damping and toughness at the same time in addition to strength which is a basic characteristic of structural materials. Further, as the use place has expanded, the demand for low temperature toughness has become more and more strict. That is, for example, in order to solve the problem of suppressing noise and vibration during high-speed railway traveling on bridges, large-scale civil engineering, and construction work with the damping effect of the structural material itself, and having sufficient toughness as a structural member. is there.

A conventional iron-based material used for a member for damping is to obtain high damping characteristics due to hysteresis due to hysteresis due to irreversible movement of domain wall movement under the action of alternating stress due to vibration. It is divided into two types, a material to which Al and Si are added and a material to which Cr is positively added for the purpose of making the structure into a ferrite single phase by adding a former. 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, as described in JP-A-6-220583 and JP-A-5-302148, Mn is 0.1 or 0.2% or less and Cr is 1 to 5%.
There is an added ferromagnetic damping alloy. Further, there is a ferromagnetic damping alloy to which Mn is added in an amount of 0.2 to 2.5% and Cr is added in an amount of 1 to 5% as disclosed in the specification of Japanese Patent Application No. 6-258982 by the inventors.

[0004]

However, among these alloys, the alloy described in Japanese Patent Application Laid-Open No. 4-99148 has good vibration damping property because the upper limit regulation of the added amounts of Al and Si is inappropriate. This causes the formation of coarse Al-based and Si-based inclusions, and this acts as a point where fracture occurs, so that the toughness decreases. Further, since the alloy described in JP-A-52-73118 has an excessive Cr addition, the toughness of Cr-based inclusions is reduced as in the above case. Furthermore, JP-A-6-220583
The alloys described in JP-A-5-302148 and JP-A-5-302148 have good vibration damping properties because they do not contain a strength-increasing element, but have low strength. Further, the alloy shown in Japanese Patent Application No. 6-258982 has a good crystal damping property because the crystal grains are coarse, but the low temperature toughness is insufficient.

An object of the present invention is to provide an alloy satisfying both strength and toughness in addition to excellent vibration damping property.

[0006]

The high strength and high toughness damping alloy of the present invention is as follows.

% By weight, C: 0.02% or less, S
i: 0.5 to 3%, Mn: 0.2 to 2.5%, Al:
A high strength and high toughness damping alloy containing 0.005 to 5% and the balance Fe and unavoidable impurities.

% By weight, C: 0.02% or less, S
i: 0.5 to 3%, Mn: 0.2 to 2.5%, Cr:
A high strength and high toughness damping alloy containing 0.1% or more and less than 1%, Al: 0.005 to 5%, and the balance Fe and unavoidable impurities.

Further, in% by weight, P: 0.02 to
0.2%, Cu: 0.05 to 2.5%, Ni: 0.05
~ 2.5%, Mo: 0.05-4.5%, Nb: 0.0
05-0.2%, V: 0.005-0.2%, Ti:
0.005-0.1%, B: 0.0003-0.00
The high-strength, high-toughness vibration-damping alloy as described above or above, which contains 5% of one or more.

Further, in% by weight, N 2 is 0.004.
The above-mentioned or high-strength, high-toughness damping alloy containing 5 to 0.015%.

Further, in weight%, Ca: 0.001
.About.0.05%, REM: 0.001 to 0.1%, one or two kinds, or the high strength and high toughness damping alloy.

[0012]

The present invention provides a ferromagnetic iron-based ferrite alloy,
Mn, which is a solid solution strengthening element essential for increasing strength, and Si and Al, which are ferrite formers and effective for strengthening solid solution.
By the simultaneous addition of Al and Al, we succeeded in obtaining an alloy having excellent vibration damping properties as well as strength and toughness. That is, the present invention is based on a ferrite phase having a proper ferrite former 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, and the ferrite former and The addition of Si and Al, which are solid solution strengthening elements, and Mn, which is a solid solution strengthening element that causes a significant increase in strength, results in
Satisfies strength and toughness at the same time.

In the alloy of the present invention, a ferrite former is added in order to improve the magnetism and strength of the matrix, but excessive addition causes the formation of inclusions and precipitates, hinders the domain wall movement, and greatly impairs the vibration damping property. Therefore, there is an upper limit.

[0014] 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, so that it is preferably as low as possible.

In addition to being important as a deoxidizer, Si is an important ferrite former and solid solution strengthening element, so it is indispensable for ensuring vibration damping property and important for toughness. Needs to be added. On the other hand, if added in excess of 3%, inclusions such as SiO ₂ will be generated,
Since it acts as a point of fracture, it significantly reduces toughness. Therefore, the range of addition of Si is 0.5 to 3%. Further, from the viewpoint of improving toughness, 0.5 to 1.5% is desirable.
Is.

Since Mn is a solid solution strengthening element while deoxidizing and fixing S to suppress grain boundary embrittlement, at least 0.2%.
However, if more than 2.5% is added, the vibration damping property will decrease. Therefore, the amount of Mn is set to 0.2 to 2.5%. Furthermore, 1.5 is preferable from the viewpoint of increasing the strength.
~ 2.5%.

Cr is an element that coarsens ferrite grains. Therefore, it is effective for improving the vibration damping property, and although 0.1% or more is added, the toughness is significantly reduced due to the coarsening. In order to improve the toughness, the Cr content is restricted to less than 1%. However, in order to further improve the toughness, no addition is made to prevent coarsening.

Al, like Si and Mn, 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 0.005%, but in addition to inclusions such as Al ₂ O ₃ due to excessive addition, precipitates such as AlN are formed by combining with N, leading to a significant decrease in toughness, so the upper limit is set. Limit to 5%. Further, 0.2 to 0.4% is preferable from the viewpoint of improving the vibration damping property.

Further, P, Cu, which is added if necessary,
Ni, Mo, Nb, V, Ti, and B are effective elements for increasing the strength. The above amount is set as the lower limit so that the effect is not insufficient, and the above amount is set as the range in which vibration damping and toughness are not deteriorated. The upper limit.

Further, N, which is added if necessary, is an important element for improving the toughness. N is fine Al combined with Al
N is useful for refining crystal grains. In order to exert its effect, it is necessary to add at least 0.0045%. On the other hand, addition of a large amount leads to the formation of coarse precipitates such as AlN and significantly lowers the toughness at the point of fracture occurrence, so the upper limit is made 0.015%.

Further, Ca and RE added as required.
M is an element effective for improving the toughness, and the above amount is set as the lower limit so that the effect is not insufficient, and the above amount is set as the upper limit as the range where the toughness is not deteriorated.

[0022]

[Examples] First, a matchmaking alloy having the components shown in Table 1 was prepared, and a plate-like test piece having a thickness of 20 mm, a width of 40 mm, and a length of 200 mm was processed from the money, and the vibration damping property was measured by a mechanical impedance method. . The test temperature for the Charpy impact test is −
40 ° C. Table 2 shows the results.

[0023]

[Table 1]

[0024]

[Table 2]

No. 1 to 17 are alloys of the present invention, N
o. 18 to 23 are comparative alloys. The plate thickness is No. 1 to
No. 9 is 25 mm, No. Nos. 10 to 17 are 60 mm, and No. 1
8-23 is 15 mm.

No. 1 to 17 have good vibration damping performance (η ≧
0.01), high strength (≧ 440 MPa), high toughness (-4
It has an absorbed energy of ≧ 100 J) at 0 ° C. No.
Since No. 2 does not contain Cr, the vibration damping performance is No. 2. Although slightly lower than 1, it has a high value of 0.01 or more and has a higher toughness. Furthermore, No. No. 3 has Si and Mn. Four
Since Si, Mn, and Al are in particularly desirable component ranges, No. Compared with No. 1, it has better vibration damping performance, high strength and high toughness. No. 5 to 13 have a higher strength (≧ 490 MPa) because they contain a strength increasing element of the selective element. Furthermore, No. 14 and 15 have better toughness (absorption energy at -40 ° C ≥ since they contain a toughness improving element).
200J). No. Since Nos. 16 and 17 contain a toughness improving element, they have higher toughness (absorption energy at −40 ° C. ≧ 160 J).

Comparative Example No. In No. 18, since C exceeds the upper limit, the vibration damping performance is low. No. In No. 19, since Si is below the lower limit, vibration damping performance and strength are low. No. In No. 20, since Si exceeds the upper limit, vibration damping performance and toughness are low. No. Two
In No. 1, Mn is below the lower limit, so the strength is low. No. 22
Since Cr exceeds the upper limit, the toughness is low. No. In No. 23, since Al exceeds the upper limit, vibration damping performance and toughness are low.

Next, a matchmaking alloy having the components shown in Table 3 was prepared, a plate-like test piece having an original thickness of 40 mm width and a length of 200 mm was processed, and the vibration damping property was measured by a mechanical impedance method. It was The results are also shown in Table 3. No. Nos. 1 and 2 are alloys of the present invention, and No. 3 is a comparative example alloy. No. No. 1 has a plate thickness of 5.0 mm and No. No. 2 has a plate thickness of 1.0 mm and No. Three
Has a plate thickness of 2.3 mm.

[0029]

[Table 3]

No. 1 and 2 have good vibration damping performance (η ≧ 0.
020) and high strength (≧ 440 MPa).

Comparative Example No. No. 3 has low Si, and has low vibration damping performance and strength.

[0032]

According to the present invention, it becomes possible to supply ships, bridges, industrial machines and structural materials for construction, which are required to have strength, toughness and damping performance at the same time.

Claims (5)

[Claims] 1. By weight%, C: 0.02% or less, Si: 0.5 to 3%, Mn: 0.2 to 2.5%, Al: 0.005 to 5%, and the balance. A high-strength, high-toughness damping alloy composed of Fe and inevitable impurities. 2. By weight%, C: 0.02% or less, Si: 0.5 to 3%, Mn: 0.2 to 2.5%, Cr: 0.1% or more and less than 1%, Al: A high strength and high toughness damping alloy containing 0.005 to 5% and the balance Fe and unavoidable impurities. 3. Further, by weight%, P: 0.02-0.2%, Cu: 0.05-2.5%, Ni: 0.05-2.5%, Mo: 0.05- 4.5%, Nb: 0.005-0.2%, V: 0.005-0.2%, Ti: 0.005-0.1%, B: 0.0003-0.005% The high-strength, high-toughness damping alloy according to claim 1 or 2, containing one or more kinds. 4. The composition according to claim 1, further comprising N: 0.0045 to 0.015% by weight.
Alternatively, the high-strength, high-toughness damping alloy described in 3 above. 5. The composition according to claim 1, further comprising one or two of Ca: 0.001 to 0.05% and REM: 0.001 to 0.1% by weight. High strength and high toughness damping alloy.