JP3548358B2 - High-strength and high-toughness damped steel sheet and method for producing the same - Google Patents

Description

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【表２】

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削除
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【発明の効果】
本発明により、制振性能だけでなく機械的特性（高強度・高靭性）が同時に要求される船舶、橋梁、産業機械、建設用構造材料の供給が可能となり、工業界に与える効果は極めて大きい。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a high-strength vibration-damping steel sheet having high vibration-damping properties as a structural material for ships, bridges, industrial machines, and buildings, and a method of manufacturing the same.
[0002]
[Prior 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 properties of structural materials. That is, for example, noise and vibration during high-speed railway running on a bridge, large-scale civil engineering, and construction work are suppressed by the damping effect of the structural material itself, and the problem of having sufficient toughness as a structural member is to be solved. To do.
[0003]
The conventional iron-based material used for members with the purpose of damping instead of a resin sandwich type damping steel plate has high damping characteristics due to hysteresis caused by irreversible motion of domain wall motion under the action of alternating stress due to vibration. In order to obtain a ferrite former, the structure is divided into two types, a material to which Al and Si are added and a material to which Cr is positively added, in order to form a ferrite single phase by adding a ferrite former. An example of the former is a ferromagnetic damping alloy containing up to 7.05% of Al and up to 4.5% of Si as described in JP-A-4-99148. Are ferromagnetic damping alloys to which 8 to 30% of Cr is added as described in JP-A-52-73118. Further, as disclosed in JP-A 6-220583 and JP-A No. 5-302148, JP-ferromagnetic system Mn of 0.1 or 0.2% or less, with the addition of 1-5% of Cr There is a vibration alloy. In addition, the present inventors have disclosed a ferromagnetic vibration damping alloy containing 0.2 to 2.5% of Mn and 1 to 5% of Cr in Japanese Patent Application No. 6-258982 (JP-A-8-158012). Suggested. JP-A-7-278657 discloses a vibration damping alloy having high toughness and a method for producing the same.
[0004]
In addition, Ryohei Tanaka, "Synthesis of Damping Materials and Their Functions and Applications" (Kosaido, March 1992, pp. 192 to 197), as a ferromagnetic alloy, external stress causes the domain wall to move, resulting in hysteresis loss and vibration energy. It is stated that it is absorbed.
[0005]
[Problems to be solved by the invention]
However, among these alloys, the alloys described in Japanese Patent Application Laid-Open No. 4-99148 are inadequate for the upper limit of the amount of Al and Si to be added. Since it acts as an occurrence point, toughness is reduced.
[0006]
Further, large damping of the variations for not define a rolling conditions in the invention described in JP Gantaira No. 6-258982 (JP-A-8-158012), the loss factor is an indicator of vibration damping property Was 0.020 ± 0.015. The literature on vibration damping materials describes the mechanism of vibration damping alloys, and does not describe any improvement measures, specific component systems / manufacturing methods, or methods for simultaneously satisfying toughness in addition to vibration damping properties.
[0007]
An object of the present invention is to provide a high-strength, high-toughness vibration-damping steel sheet which simultaneously satisfies excellent vibration damping properties with little variation and mechanical properties of strength and toughness, and a method for producing the same.
[0008]
(1) In mass%, C: 0.02% or less, Si: 0.01% or more and 3.5% or less, Mn: less than 0.2%, P: 0.010% or less, S: 0.005 %, Cr: 0.02% to 3.5%, Al: 0.002% to 3.5%, N: 0.006% or less, with the balance being Fe and unavoidable impurities A high-strength, high-toughness vibration damper characterized by a crystal grain size of 100 μm or less and a (200) diffraction intensity ratio of 2.5 to 12.0 at a quarter thickness position in the thickness direction. Steel sheet .
[0009]
(2) Further, in mass%, Cu: 0.05 to 2.5%, Ni: 0.05 to 2.5%, Mo: 0.05 to 4.5%, Nb: 0.005 to 0.5%. 2%, V: 0.005 to 0.2%, Ti: 0.005 to 0.1%, B: 0.0003 to 0.005%. The high-strength, high-toughness damped steel sheet according to (1).
[0010]
(3) The above-mentioned (1) or (1), further comprising one or two kinds of Ca: 0.001 to 0.05% and REM: 0.001 to 0.1% by mass%. The high-strength, high-toughness damped steel sheet according to 2).
[0011]
(4) In mass%, C: 0.02% or less, Si: 0.01% or more and 3.5% or less, Mn: less than 0.2%, P: 0.010% or less, S: 0.005 %, Cr: 0.02% to 3.5%, Al: 0.002% to 3.5%, N: 0.006% or less, with the balance being Fe and unavoidable impurities After hot rolling the steel at a heating temperature of 1000-1200 ° C., a rolling reduction of 950 ° C. or less at 30-70%, a finishing temperature of 600-850 ° C., and then performing a tempering or annealing heat treatment at 600 ° C.-950 ° C. Characteristic method for producing a high-strength, high-toughness damped steel sheet having a crystal grain size of 100 μm or less and a (200) diffraction intensity ratio of 2.5 to 12.0 at a quarter thickness position in the thickness direction. .
[0012]
(5) Further, in mass%, Cu: 0.05 to 2.5%, Ni: 0.05 to 2.5%, Mo: 0.05 to 4.5%, Nb: 0.005 to 0.5%. 2%, V: 0.005 to 0.2%, Ti: 0.005 to 0.1%, B: 0.0003 to 0.005%. The method for producing a high-strength, high-toughness damped steel sheet according to (4).
(6) The above (4) or (4), further comprising one or two kinds of Ca: 0.001 to 0.05% and REM: 0.001 to 0.1% by mass%. The method for cracking a high-strength, high-toughness damped steel sheet according to 5).
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention has been made in view of the above circumstances, in order to obtain high vibration damping characteristics due to hysteresis due to domain wall movement irreversible movement under the action of alternating stress due to vibration, various elements and inclusions harmful to domain wall movement, It is based on a pure iron-based component in which elements that cause generation of precipitates, hinder domain wall movement, and greatly impair damping properties are reduced as much as possible.
[0014]
Further, conventionally, since the crystal grain boundaries hinder domain wall movement, the vibration suppression was improved solely by coarsening, but as a result of various studies, the present inventors have found that the vibration suppression is improved by the coarsening. As an alternative to the above method, it has been found that by increasing the (200) diffraction intensity, the vibration damping property is greatly improved. By increasing the (200) diffraction intensity, the <100> direction 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 finding that the vibration damping property is improved by strengthening the easy magnetization direction.
[0015]
When the (200) diffraction intensity ratio is 2.5 or more, the loss coefficient which is an index of damping properties can be secured 0.015 or more. Further, from the viewpoint of vibration damping performance alone, the higher the (200) diffraction intensity ratio, the better, and as a result, a loss coefficient of 0.015 to 0.05 can be secured. For practical use, the (200) diffraction intensity ratio is preferably in the range of 2.5 to 12.0 in consideration of other steel properties such as toughness. Here, the (200) diffraction intensity ratio is obtained by measuring the (200) diffraction intensity at a quarter thickness position in the plate thickness direction by X-ray diffraction, and strengthening or controlling a specific orientation of a random sample material. The ratio to the (200) diffraction intensity was determined. According to the results of this study, the (200) diffraction intensity ratio was about 15 at the maximum.
[0016]
In order to increase the (200) diffraction intensity ratio, it is necessary to perform low-temperature rolling, and as a result of examination, it can be achieved by setting the rolling reduction at 950 ° C. or less to 30% or more. For this reason, the rolling finishing temperature is 950 ° C. or less.
[0017]
Delete [0018]
Next, in order to improve toughness, it is necessary to reduce the crystal grain size to 100 μm or less . When the rolling finish temperature is less than 600 ° C. in the above-mentioned production method in which the (200) diffraction intensity ratio is 2.5 or more, the crystal grain size may exceed 100 μm, so the roll finish temperature is set to 600 ° C. or more.
[0019]
After hot rolling, tempering or annealing heat treatment is required to increase the (200) diffraction intensity ratio and reduce the strain introduced into the steel sheet by rolling. , The upper limit temperature is 950 ° C.
[0020]
As described above, the introduction of the texture in the fine-grained structure improves the vibration damping property. However, further study was made on the improvement of the vibration damping property. As a result, it has been found that the addition of Si, Al, and Cr, which are ferrite formers, achieves some coarsening in the process of heat treatment for removing strain after hot rolling, and further improves vibration damping properties. The strength also increases with the addition of Si, Al and Cr.
[0021]
Next, the reasons for limiting the steel components of the present invention will be described.
[0022]
C is preferably as low as possible because C acts as a hindrance to domain wall movement and lowers the vibration damping property, regardless of whether it is in a solid solution state or as a carbide, and the upper limit is made 0.02%.
[0023]
Since Si is important as a deoxidizing agent, it must be added at 0.01% or more . Further, it is necessary for increasing the strength, and is a ferrite former, and by adding, a slight coarsening is achieved in the process of heat treatment for removing strain after hot rolling , which further improves vibration damping properties . Therefore , it is preferable to add 0.50% or more . However, even if it is added in excess of 3.5%, the vibration damping property is rather lowered and the cost is increased. Therefore, the upper limit is set to 3.5%.
[0024]
Mn is a solid solution strengthening element, has no effect on improving vibration damping properties and toughness, and increases the cost by adding Mn. Therefore, the upper limit is made less than 0.2%.
[0025]
Since P and S form nonmetallic inclusions in steel and cause segregation to hinder the movement of the magnetic domain wall and lower the damping performance, the smaller the amount, the better. Therefore, P is set to 0.010% or less and S is set to 0.005% or less.
[0026]
Al, in addition important as Si as well as a deoxidizer, damping property, is an important element to improve the strength, it is necessary to ensure a minimum of 0.002%. In addition, it is necessary for increasing the strength , and it is a ferrite former, and by adding it, during the strain relief heat treatment after hot rolling, slight coarsening is achieved, further improving vibration damping properties Therefore , it is preferable to add 0.060% or more . However, even if it is added in excess of 3.5%, the vibration damping property is rather lowered and the cost is increased. Therefore, the upper limit is set to 3.5%.
[0027]
Cr is an element that coarsens the crystal grains and slightly improves the vibration damping properties, so Cr is added in an amount of 0.02% or more. Further, in necessary in order to increase strength, also a ferrite former, some grain coarsening in the process of stress relief heat treatment after hot rolling is achieved by adding further improve the vibration damping property Therefore , it is preferable to add 0.50% or more . However, even if it is added in excess of 3.5%, the vibration damping property is rather lowered and the cost is increased. Therefore, the upper limit is set to 3.5%.
[0028]
N is also precipitated as nitride in a solid solution state, the lower the order to reduce the vibration damping property acts as a failure of the domain wall motion preferably, the upper limit 0.006%.
[0029]
Further, Cu is added as required, Ni, Mo, V, Ti, B is an element effective-strength increase, and the amount in the range where the effect is not insufficient lower limit, also vibration-damping properties and The amount in the range where the toughness does not decrease is set as the upper limit. Therefore, C u: 0.05~2.5%, Ni : 0.05~2.5%, Mo: 0.05~4.5%, Nb: 0.005~0.2%, V: 0.005 to 0.2%, Ti: 0.005 to 0.1%, and B: 0.0003 to 0.005%.
[0030]
Furthermore, Ca is added if necessary, REM is an element effective on toughness propensity, the amount in the range where the effect is not insufficient lower limit, or, toughness is rather reduced, the vibration damping property The amount which does not decrease is set as the upper limit. Therefore, Ca: 0.001 to 0.05% and REM: 0.001 to 0.1%.
[0031]
The production conditions, heating temperature, and the pressurized heat austenite grains fine, and (200) to increase the diffraction intensity ratio, and 1200 ° C. or less, further, to eliminate the steel in the temperature difference during heating, 1000 ° C. or higher I do.
[0032]
Regarding the rolling conditions, it is necessary to roll at 30% or more at 950 ° C. or less in order to increase the (200) diffraction intensity ratio. However, when the rolling reduction exceeds 70%, the load on the rolling mill increases, and The upper limit is set to 70% because the time becomes longer and the cost increases.
[0033]
The rolling finish temperature is 850 ° C. or less because rolling at 30% or more is performed at 950 ° C. or less. However, when the temperature is less than 600 ° C., ferrite is rolled and the crystal grain size may exceed 100 μm, and the toughness is reduced. , And the lower limit is 600 ° C.
[0034]
After cooling to room temperature , tempering or annealing heat treatment is required to further improve the (200) diffraction intensity ratio and reduce the strain introduced into the steel by rolling, and heat treatment at 600 ° C. or higher is performed. Since the (200) diffraction intensity ratio becomes weaker when heat treatment is performed at a high temperature, the upper limit temperature is set to 950 ° C.
[0035]
Furthermore, it is necessary to harden the surface in fields such as mechanical members and bearings where high hardness is required only on the surface, but the vibration damping material according to the present invention has a common-sense surface hardened layer thickness, It was confirmed by experiments that the damping characteristics were hardly affected. As for the surface hardening, the hardness of the steel material surface can be hardened to Hv700 or more by carburizing or nitriding .
[0036]
Delete [0037]
Delete
Delete [0039]
As described above, as a result of thoroughly examining and specifying the component system and the manufacturing method, it is necessary to provide a steel material that simultaneously satisfies the vibration damping property and the strength and toughness with a high loss coefficient of 0.025 ± 0.010 and very little variation. Became possible.
[0040]
The present invention mainly relates to a steel sheet and a hot-rolled steel sheet, but can also be manufactured as a shaped steel, a wire / bar, a steel pipe and the like.
[0041]
【Example】
Also not a, to create a test game gold component ranges shown in Table 1, a test piece was prepared in the manufacturing conditions shown in Table 2. The plate thickness is 20 mm for A1 to A9 , 3 mm for A11 to A15 , 50 mm for A17 and A19 , 32 mm for B1 to B8, and 10 mm for B9 to B17.
[0042]
Among the steels shown in Table 2, A1 to A19 are steels of the present invention, and steels B1 to B17 are comparative examples. The various properties of these steels manufactured under the manufacturing conditions shown in Table 2 are also shown in the table. For the vibration damping property, a plate-shaped test piece having an original thickness × 40 mm width × 400 mm length was processed, and the vibration damping property was measured by a mechanical impedance method . (Note that the steel plate or sheet thickness 6 mm, after hot rolling, after cooling to room temperature, and heat treated. Plate thickness after between the hot rolling less things, winding, and then heat-treated.)
The present invention examples of Examples A1 to A19 are alloys in the component range of the present invention , and the production conditions are in the production method range of the present invention. Therefore , the (200) diffraction intensity ratio is 2.5 or more, and the high intensity (≧ 450 MPa) , exhibiting high damping properties (loss coefficient) (≧ 0.025) and high toughness (≧ 100 J).
[0043]
Comparative Examples B1 to B8 are alloys outside the component range of the present invention, and have a low (200) diffraction intensity ratio and low vibration damping performance and toughness. Comparative Examples B9 to B17 have low (200) diffraction intensity ratios and low vibration damping performance and toughness under the manufacturing conditions other than the manufacturing method of the present invention. B15 also has low strength.
[0044]
Delete [0045]
[Table 1]

[0046]
[Table 2]

[0047]
Delete
【The invention's effect】
According to the present invention, it is possible to supply ships, bridges, industrial machines, and structural materials for construction that require not only damping performance but also mechanical properties (high strength and high toughness) at the same time, and the effect on the industrial industry is extremely large. .

Claims (6)

In mass%,
C: 0.02% or less,
Si: 0.01% or more and 3.5% or less,
Mn: less than 0.2%,
P: 0.010% or less,
S: 0.005% or less,
Cr: 0.02% or more and 3.5% or less,
Al: 0.002% or more and 3.5% or less,
N: 0.006% or less, the balance being Fe and unavoidable impurities, the crystal grain size is 100 µm or less, and the (200) diffraction intensity ratio at a quarter thickness position in the thickness direction is 2.5. A high-strength, high-toughness vibration-damping steel sheet , characterized by being 12.0 to 12.0. Furthermore, in mass%,
Cu: 0.05-2.5%,
Ni: 0.05-2.5%,
Mo: 0.05 to 4.5%,
Nb: 0.005 to 0.2%,
V: 0.005 to 0.2%,
Ti: 0.005 to 0.1%,
B: 0.0003-0.005%
The high-strength and high-toughness vibration-damping steel sheet according to claim 1, wherein one or more kinds are contained. Furthermore, in mass%,
Ca: 0.001 to 0.05%,
REM: 0.001-0.1%
The high-strength and high-toughness damped steel sheet according to claim 1, wherein the steel sheet contains one or two of the following. In mass%,
C: 0.02% or less,
Si: 0.01% or more and 3.5% or less,
Mn: less than 0.2%,
P: 0.010% or less,
S: 0.005% or less,
Cr: 0.02% or more and 3.5% or less,
Al: 0.002% or more and 3.5% or less,
N: A steel containing 0.006% or less, with the balance being Fe and unavoidable impurities, having a heating temperature of 1000 to 1200 ° C, a rolling reduction of 950 ° C or less of 30 to 70%, and a rolling finish temperature of 600 to 850 ° C. Characterized by a tempering or annealing heat treatment at 600 to 950 ° C. at a crystal grain size of 100 μm or less and a (200) diffraction intensity ratio at a quarter thickness position in the plate thickness direction. A method for producing a high-strength, high-toughness vibration-damping steel sheet of 2.5 to 12.0. Furthermore, in mass%,
Cu: 0.05-2.5%,
Ni: 0.05-2.5%,
Mo: 0.05 to 4.5%,
Nb: 0.005 to 0.2%,
V: 0.005 to 0.2%,
Ti: 0.005 to 0.1%,
B: 0.0003-0.005%
The method for producing a high-strength and high-toughness vibration-damping steel sheet according to claim 4, wherein one or more kinds are contained. Furthermore, in mass%,
Ca: 0.001 to 0.05%,
REM: 0.001-0.1%
The method for producing a high-strength and high-toughness damped steel sheet according to claim 4, wherein the steel sheet contains one or two of the following.