JP3211637B2 - Steel plate for vibration damping device and method of manufacturing 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 control device (vibration damper) for absorbing the vibration energy of a building structure when it receives vibration such as an earthquake to ensure safety.
The present invention relates to a steel sheet used for a steel sheet and a method for manufacturing the steel sheet.

[0002]

2. Description of the Related Art When a building structure receives vibration such as an earthquake, the following method has been proposed to absorb the vibration energy and ensure safety.

(1) A method of absorbing vibration energy by deforming a structural member, that is, a method of using a low-yield-ratio material for the structural member, (2) Inserting a cushioning member such as an anti-vibration rubber into the foundation of the structure or the like (3) A method of attaching a vibration damping device to a structure to attenuate vibrations, (4) Even if an earthquake causes damage, the structural members are not completely broken but some members are deformed A method of inserting a shock absorbing device into a structure.

Recently, a vibration control device (also referred to as a vibration control damper) aiming at a combined effect of the above (3) and (4) has been developed. The vibration damping device is inserted between the girders of the building structure.

FIGS. 1A and 1B are views showing a vibration control device, wherein FIG. 1A is a front view and FIG. 1B is a side view. The vibration damping device 1 includes a cylindrical support shaft 11, a T-shaped base 12, two arms 13, 13, a shaft 14, and a bearing 15. As shown in the figure, a T-shaped base 12 is attached to a central portion of a cylindrical support shaft 11, and two arms 13 are attached to both ends of the cylindrical support shaft. A shaft 14 is inserted and fixed to the other ends of the two arms. A bearing 15 is rotatably mounted on the shaft 14.

FIGS. 2A and 2B are diagrams showing a part of a structure to which a vibration damping device is attached, wherein FIG. 2A is a front view and FIG. 2B is a side view. 1 is a vibration control device, 2 is a girder, and 3 is a bending column. Further, the T-shaped base 12 and the bearing 15 of the vibration damping device are fixed to the upper and lower bent columns 3 facing each other, and the bent columns are respectively attached to the girders 2. Therefore, the upper and lower girders are connected so as to follow the vibration in the longitudinal direction of the girder, and absorb the vibration of the building structure caused by the earthquake. It also aims to prevent the complete destruction of building structures by deforming the cylindrical support shaft of the damping device when a large earthquake occurs. For this purpose, it is necessary for the cylindrical support shaft to yield uniformly and to be plastically deformed.
Up to 280 N / mm ² , yield strength in the range of 100 to 150 N / mm ² , small variation, elongation of 40% or more, and absorbed energy (vEo) in V-notch Charpy impact test of 47 J or more , Is required.

Conventionally, in order to improve the safety of buildings and bridges, a material having a large energy absorption amount in a structural member during an earthquake, that is, a material having a low yield ratio has been desired, and various manufacturing methods have been proposed as follows. Have been.

(1) A method of producing a low-yield-ratio steel material having a yield shelf by applying light pressure reduction before water cooling, while suppressing excessive grain refinement of ferrite and refinement of carbides of the second phase. JP-A-4-45226 and JP-A-4-45
(See No. 227), (2) While reducing the reinforcing components of steel, the decrease in strength due to this reduction is compensated for by increasing the amount of Si, and the deterioration in weldability due to the increase in Si is reduced by the amount of Si and Mn. Prevent by defining the ratio. Further, by quenching from the austenite region, the yield strength is 280 N / mm ²
Above, V notch Charpy absorbed energy (vEo) is 28Nm
(J) a low yield point hardened steel for spherical bow and a method for producing the same (refer to Japanese Patent Application Laid-Open No. 5-70885), (3) the addition of Si A method of producing a structural steel having a low yield strength by causing abnormal growth of crystal grains during a temperature rise process during normalization (see JP-A-5-320761), (4)
A method for suppressing the addition of strengthening elements, adding Si and Al, causing abnormal growth of crystal grains during the temperature rise process during normalizing after hot rolling, and producing a structural steel with low yield strength (particularly, Kaihei 5-
No. 320762).

As a countermeasure for reducing the noise of transportation and the vibration of factories, the following vibration absorbing materials having the vibration absorbing ability of the material itself have been proposed.

(1) A method for improving the vibration damping performance of a structure by applying stress relief annealing to a structure made of a steel material to which Si and Al are added in combination to cause abnormal growth of crystal grains (Japanese Patent Laid-Open No. (Refer to JP-A-5-331540), (2) A method of improving the vibration damping performance of a structure by causing stress-relieving annealing of a structure made of a steel material to which Si is added to cause abnormal growth of crystal grains. See JP-A-5-331541).

[0011]

Since the above-mentioned low-yield strength steel materials are used as building structures and hull structural members, they ensure a tensile strength of 500 N / mm ² or more and improve workability. The yield strength is reduced to improve or absorb the vibration energy of the structure during an earthquake. But,
Yield strength of steel sheet used for vibration control device is 100 ~
There is a demand for a material having a low strength of 150 N / mm ² , a small variation, a tensile strength of 220 to 280 N / mm ² , an elongation of 40% or more, and a large absorption energy at impact.

It is an object of the present invention to provide a steel having a tensile strength of 220 to 280 N / mm ² and a yield strength of 100 to 15 without containing Si.
An object of the present invention is to provide a steel material for a vibration control device having a small variation in the range of 0 N / mm ² and an elongation of 40% or more.

[0013]

Means for Solving the Problems The present inventor can adjust the yield strength to a range of low yield strength by subjecting a pure iron-based steel material to hot finish rolling at a low temperature and then subjecting it to a roughening heat treatment at an appropriate temperature. Was found.

The present invention has been completed on the basis of this finding, and the gist of the invention resides in the following manufacturing method for a steel sheet having a low yield strength.

In mass%, C: 0.002-0.040%, Si:
0.02% or less, Mn: 0.05 to 0.30%, Al: 0.005 to 0.050
%, N: 0.005% or less, with the balance being Fe and unavoidable impurities and having a yield strength of 100 to 150 N / mm ² .

In mass%, C: 0.002-0.040%, Si:
0.02% or less, Mn: 0.05 to 0.30%, Al: 0.005 to 0.050
%, N: 0.005% or less, the ingot consisting of the balance Fe and unavoidable impurities is finished by hot rolling to a temperature range of 710 to 780 ° C, and then heat treated for coarsening at a temperature range of 850 to 910 ° C. A method for producing a steel plate for a vibration damping device having a yield strength of 100 to 150 N / mm ² by applying the heat treatment.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The reasons for limiting the chemical components in the present invention are as follows. Hereinafter,% representing the component content indicates mass%.

C: 0.002 to 0.040% C is added to secure the strength of the material. When the content thereof is less than 0.002%, 220 N / mm ² or more in tensile strength Sagae is not the case containing no Si and Mn, is a yield strength greater than 0.040 percent exceed 150 N / mm ² I will. Therefore, the C content is set to 0.002 to 0.040%. Preferred is
0.002 to 0.008%.

Si: 0.02% or less Si is an element that increases the strength of steel by solid solution strengthening, but need not be added in the strength range required in the present invention. That is, it may be substantially 0%. However, keeping it low will increase costs,
The upper limit was set to 0.02%.

Mn: 0.05 to 0.30% Mn is an element that improves strength and toughness. C and Si
In order to obtain a tensile strength of 220 N / mm ² or more only by containing Mn without containing Mn, 0.05% or more is necessary. But 0.3
%, The yield strength exceeds 150 N / mm ² . Therefore,
The Mn content was 0.05-0.3%.

Al: 0.005 to 0.05% Al is an element necessary for deoxidation at the time of smelting. Since deoxidation by Si is not performed, the effect of deoxidizing is less when the content is less than 0.005%, and when it exceeds 0.05%, the cost is increased. Invite up.

N: 0.005% or less N is an element that increases the yield strength by solid solution strengthening and fixation of dislocations. However, lowering the N value unnecessarily increases the cost, so the allowable upper limit is set.
0.005%.

In addition, as materials for specifying the material, the tensile strength is set to 220 to 280 N / mm ² and the yield strength is set to 100 to 150 N / mm ² .

When the tensile strength is less than 220 N / mm ² , the shape of the cylindrical support member of the vibration damper becomes large. 280 N tensile strength
If it exceeds / mm ² , the yield strength becomes 150 N / mm ² or more, which is not preferable. The reason for the yield strength of the 100 to 150 N / mm ^2, the cylindrical support member made of the steel material, early plastic deformation during an earthquake, and also maintain a uniform stable properties during the deformation Needed above.

Next, the reason for defining the manufacturing method will be described.

Rolling temperature: 710 to 780 ° C. Hot finish rolling is performed in a low temperature range, a proper amount of strain is introduced into the material, and the material is subjected to a coarse-graining heat treatment to have a low yield strength and a small variation. A steel sheet is obtained.

If the rolling finish temperature is lower than 710 ° C., too much distortion is introduced, and if it exceeds 780 ° C., the distortion introduced is small, and both are unfavorable because the yield strength becomes high.

Coarse grain heat treatment: 850 to 910 ° C. Coarse grain is formed by heat-treating the strained material. However, if the treatment temperature is lower than 850 ° C., the effect is not obtained.

[0029]

EXAMPLES Steel having the components shown in Table 1 was melted in a converter to form a continuous cast slab, heated to 1000 to 1250 ° C., and then hot-rolled. It was rolled at a hot rolling temperature. The obtained steel sheet was treated at the heat treatment temperature shown in Table 1 and air-cooled, and then three tensile test pieces (JIS No. 5 test pieces) were collected from the front, center and end of the heat-treated material, respectively, and the tensile strength was measured. Yield strength and elongation were determined. Table 2 shows the results.

[0030]

[Table 1]

Nos. 1 to 10 of the invention examples have a tensile strength of 225
280 N / mm ² and yield strength in the range of 110-145 N / mm ² , all of which satisfy the requirements for vibration damping devices.

However, in Comparative Example No. 11, the C content was 0.1%.
Since 001% is less than the lower limit of the range defined in the present invention, the yield strength is as low as 90 N / mm ² .

In No. 12, since the C content was 0.05%, which was larger than the upper limit of the range defined in the present invention, the yield strength was 155 N / m2.
It was as high as m ^2.

In No. 13, since the Mn content was 0.03%, which was smaller than the lower limit of the range defined in the present invention, the yield strength was 95 N /
was as low as mm ^2.

In No. 14, since the Mn content was 0.50%, which was larger than the upper limit of the range defined in the present invention, the yield strength was 180 N / m2.
It was as high as m ^2.

In No. 15, since the N content is 0.006%, which is larger than the upper limit of the range defined in the present invention, the yield strength is 160 N.
/ it was as high as mm ^2.

Nos. 16 to 23 are examples in which steel pieces having the same chemical composition were used and the hot rolling temperature and the heat treatment temperature were changed.

In No. 16, since the hot rolling finish temperature was as low as 700 ° C., the yield strength was as high as 155 N / mm ^2.
In No. 7, since the hot rolling finish temperature was as high as 790 ° C., the yield strength was as high as 155 N / mm ² .

In No. 18, since the heat treatment temperature was as low as 830 ° C., the yield strength increased to 165 N / mm ^2, and No. 19
Has a high yield temperature of 155 N
/ it was as high as mm ^2.

[0040]

Steel sheet of the present invention exhibits, 100-150 since yield strength of N / mm ² can be stably obtained, when using the steel plate as a cylindrical support member Damping device structures during an earthquake Is absorbed as deformation energy due to the yielding of the material, and a vibration control effect can be exhibited.

[Brief description of the drawings]

FIG. 1 is a view showing a vibration control device, (a) is a front view, (b).
Is a side view.

FIG. 2 is a view showing a part of a structure to which a vibration control device is attached, (a) is a front view, and (b) is a side view.

[Explanation of symbols]

 1. 2. Vibration control device 2. Girder 3. Bent column 11． Cylindrical support 12. T-type base 13. Arm 14. Axis 15． bearing

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C22C 38/00-38/60 C21D 8/00-8/02

Claims (2)

(57) [Claims] (1) In mass%, C: 0.002 to 0.040%, Si: 0.
02% or less, Mn: 0.05 to 0.30%, Al: 0.005 to 0.050%,
N: A steel sheet for a vibration control device characterized by containing 0.005% or less, the balance being Fe and unavoidable impurities, and having a yield strength of 100 to 150 N / mm ² . (2) In mass%, C: 0.002 to 0.040%, Si: 0.
02% or less, Mn: 0.05 to 0.30%, Al: 0.005 to 0.050%,
N: A cast slab containing 0.005% or less, with the balance being Fe and unavoidable impurities, is hot-rolled, subjected to finish rolling in a temperature range of 710 to 780 ° C, and then heat-treated in a temperature range of 850 to 910 ° C. Yield strength of 100 to 150 N / m
method of manufacturing a vibration control device for a steel plate is m ^2.