JPH0774415B2 - Fe-Mn vibration damping alloy steel and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping alloy having a vibration damping property, and more specifically, an iron-manganese (Fe-Mn) vibration damping alloy having a high damping property and an excellent damping property. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Recently, a vibration damping alloy material having an excellent damping property is provided to prevent vibrations and roars generated from machines and equipments of various industries such as aircraft, ships, vehicles, machinery or precision instruments. Use is spreading.

As conventional vibration-proof alloys, Cu-Mn alloys, Ni-Ti alloys and stainless alloy steels utilizing twin transformation are known.

Although such an alloy has an excellent damping property near room temperature, it uses an expensive metal, which causes an increase in the unit price of the product, which deteriorates the cold workability and the manufacturing process due to each element. Precision and complexity are required. Further, the Al—Zn alloy and the main iron-based alloy have insufficient tensile strength or hardness.

On the other hand, high-Mn steel, austenite (Au
Stenite) type low temperature vibration-proof alloy is disclosed in Japanese Patent Laid-Open No. 5
Known from 6-258. Chromium (C
r) and aluminum (Al) or Mo, V, Nb, T
Since elements such as i are added, it is a factor for increasing the unit price of the product, and it is necessary to strictly adjust the carbon (C) and Cr contents in the contained components in order to obtain a stable austenite composition. Requires proper physical properties for austenite.

The main forms of vibration damping are roughly classified into three types: relaxation type, resonance type and hysteresis type. The damping by the relaxation type does not depend on the amplitude of vibration but on the frequency and is not considered so much in terms of vibration isolation.

As in the relaxation type, the damping type does not depend on the amplitude of vibration as in the relaxation type, but depends on the frequency. In this case, the maximum damping is obtained at the resonance frequency. . However, the damping property of such a form is not so important in terms of vibration damping alloys.

The hysteresis type is a damping mode caused by the difference between the stress-deformation path when the stress is applied from the outside and the stress-deformation path when the stress is removed. At this time, the energy corresponding to the relaxation loss is attenuated. Cause. Therefore, the damping property of this form is characterized by being largely dependent on the deformation amplitude regardless of the frequency. Since such a hysteresis type may exhibit an excellent damping property regardless of the frequency, it can industrially provide a vibration damping effect.

[0009]

Therefore, the alloy of the present invention was developed as a hysteretic vibration-proof alloy. Iron (Fe) is used as a base, and manganese (Mn) is added to the alloy to increase the cost. It is an object of the present invention to provide an inexpensive vibration-damping alloy that can obtain an excellent damping alloy while maintaining high strength without using other elements and can be used at room temperature.

[0010]

The present invention is described below as follows.

According to the present invention, Fe is the main component, and 10 to 22% of Mn is added thereto in a weight percentage, and martensite (Marte
Fe-Mn-based vibration damping alloy having a nsite structure.

In producing the alloy steel of the present invention, first, electrolytic iron and electrolytic manganese are prepared in the above composition ratio, and the furnace temperature is set to 1500 in an induction furnace or an electric furnace.
First, the electrolytic iron is melted at a temperature of not lower than ℃, and then electrolytic manganese is put into this to dissolve.

Then, it is cast into a mold to make an ingot. This is homogenized at 1000 to 1300 ° C. for 20 to 40 hours, and then hot-rolled into a predetermined shape. Then, at 900 to 1100 ° C. for 20 minutes to 1 hour 30
The alloy steel of the present invention having a martensitic structure is obtained by heating for about a minute and then air cooling or water cooling.

In the present invention, the Mn content is set to 10 to 22% by weight because α'-martensite is formed up to 10% Mn content and ε-martensite starts to form at Mn content of 10% or more. This is because when the Mn content is 28% or more, the structure becomes an austenite structure, but the α'-martensite structure has a small vibration damping property, and the ε-martensite structure has a very large vibration damping property. Therefore, the range of excellent vibration damping is set to 10 to 22% by weight.

In the present invention, C, Si, P and S elements are not particularly limited, but since the present invention is for obtaining a martensitic structure as a high Mn steel, C
It is considered that the effect on Si and Si does not significantly affect.

Further, P and S are unavoidable impurities, and if they are not more than the range that affects steel, they are not particularly problematic and are not limited separately.

The homogenization conditions (temperature, time) are as follows:
It is for completely dissolving Mn and other impurity elements in austenite.

[0018]

EXAMPLE Next, Table 1 to Table 3 and FIG.
This will be described through the embodiment shown in FIG. FIGS. 1 and 2 show the Fe side portion of the Z-element system phase diagram of Fe-Mn, which is the basis of the present invention, and the transition point of this phase diagram is thermal expansion after cooling at a cooling rate of 3 ° C./min. It was determined by conducting tests, magnetic analysis, X-ray diffraction test and optical microscope test.
In FIG. 1, α′-martensite is produced up to a Mn content of 10%, mixed martensite of α ′ + ε is produced at a Mn content of 10 to 15%, and ε martensite is produced at a Mn content of 15 to 28%. . Figure 2 shows each Mn alloy at 1000 ° C.
After heating to room temperature and air-cooling at room temperature, the volume fraction of each phase was investigated by X-ray diffraction analysis. As a result of the investigation as shown in FIGS. 1 and 2, the alloy showing α′-martensite as shown in Table 1 has a very small vibration damping property, and the alloy showing the ε-martensite structure has a very large vibration damping property. It was found to be extremely large and the tensile strength was excellent.

FIG. 2 shows the volume fraction of each layer investigated by X-ray diffraction analysis after heating each Mn alloy at 1000 ° C. and air-cooling at room temperature. As a result of the investigation as shown in FIGS. 1 and 2, as shown in Table 1, the alloy showing α′-mantensite has a very small vibration damping property, and the alloy showing the ε-mantensite structure has a very large vibration damping property. It was found to be large and the tensile strength was excellent.

[0020]

The reason why ε-martensite has a larger vibration damping property than α′-martensite is that the substructure of α′-martensite is a dislocation, and
The substructure of martensite is a fine twin, and the twin boundary is easily moved by a small external force. Therefore, it is considered that ε-martensite exhibits a high vibration damping property. Here, damping property (damping capacity: Specific Dampi)
ng Capacity: SDC%) is calculated as follows. SDC (%) = (ΔW / W) × 100 = {(A _n ² −A _{n + 1} ² ) / A _n ² } × 100 where ΔW: vibration energy loss per cycle W: vibration per cycle Energy A _n : Amplitude of _nth vibration A _{n + 1} : Amplitude of _{n + 1} vibration

[0022]

As shown in Table 2 above, the steel according to the present invention is superior to the comparative steel in the air-cooling property or the water-cooling property, and the damping property is excellent.

[0024]

In the case of the present invention as shown in Table 3 above, the strength, that is, the hardness value (HRB) here is in the range of 88 to 90, while the comparative steel has 85 or less, particularly Fe-28%.
In the case of Mn, it shows that the austenite structure decreases to 60.

Further, FIG. 3 shows an amplitude attenuation curve when a rod-shaped sample is freely vibrated at a maximum surface deformation rate r−2 × 10 ⁴ . Here, the vertical axis represents amplitude and the horizontal axis represents time (seconds). (A) of FIG. 3 is Fe-4% Mn steel which is α′-martensite, and the amplitude hardly changes with the passage of time, but (B) of FIG. 3 is Fe having an ε-martensite structure. For -17% Mn steel, the amplitude disappears rapidly over time.

[0027]

As described in detail above, those within the Mn range of the present invention have the effect that they are superior in vibration damping property to the comparative steel.

[Brief description of drawings]

FIG. 1 is a binary phase diagram of the Fe—Mn alloy of the present invention.

FIG. 2 is a phase diagram of the Fe—Mn alloy of the present invention.

FIG. 3 is a vibration damping curve diagram of the Fe—Mn alloy of the present invention, (A) is a phase diagram of the Fe-4% Mn alloy,
(B) is a phase diagram of a Fe-17% Mn alloy.

Claims (2)

[Claims] 1. A Fe—Mn vibration damping alloy steel having a martensite structure, characterized by containing 10 to 22% by weight of manganese (Mn) based on iron (Fe). 2. Electrolytic iron and electrolytic manganese are mixed and dissolved, and a molten metal containing 10 to 22% by weight of Mn and the balance of Fe is cast to form an ingot, which is 1000 to 1
Fe-Mn-based vibration of martensite structure characterized by being homogenized at 300 ° C for 20 to 40 hours, hot-rolled, heated at 900 to 1100 ° C for 30 minutes to 1 hour, and then air-cooled or water-cooled. Damped alloy steel manufacturing method.