Low yield strength damper steel plate for building and method for manufacturing the same

Abstract

The application relates to the technical field of building steel plates, in particular to a low-yield-strength damper steel plate for buildings and a preparation method thereof; the chemical components of the damper steel plate, in terms of mass fractions, include C<=0.0025%, Si<=0.006%, Mn: 0.10%-0.15%, Ti: 0.06%-0.08%, and the rest are Fe and inevitable impurities; through component design, the low-carbon content of C lower than 0.0025% can reduce the cementite content in the steel plate, thereby reducing the strength of the steel plate; meanwhile, low Si and low Mn contents are adopted, and then the solid solution effect is weakened, so that the strength of the steel plate can be reduced; then 0.06%-0.08% of Ti is added, so that more Ti is used to fix C, C gap solid solution is avoided to generate a yield platform, and thus the damper steel plate with extremely low yield strength, a low yield strength ratio, good plasticity and low-temperature toughness can be obtained.

Description

Technical Field

[0001] This application relates to the field of steel plate technology for construction, and in particular to a low yield strength steel plate for building dampers and its preparation method. Background Technology

[0002] High-rise buildings can significantly improve the utilization rate of limited urban land resources and save on construction costs per unit area. In recent years, high-rise buildings have also developed rapidly in various developed cities. However, high-rise buildings are currently experiencing large amplitude vibrations due to earthquakes, which can seriously affect their safety. Therefore, seismic performance is a key issue that needs to be considered in the design and manufacture of high-rise buildings.

[0003] Traditional seismic design resists earthquakes by enhancing the seismic performance of the structure itself, but this method lacks self-regulation capabilities. Currently, dampers made of low-yield-strength steel plates are excellent damping components that can absorb a large amount of energy, and are therefore widely used in the design and construction of high-rise buildings.

[0004] Dampers mainly use steel plates with low yield strength. They generally require extremely low yield strength, low yield strength ratio, good plasticity and low temperature toughness, which makes it difficult to manufacture the technical specifications of dampers. Existing dampers are difficult to achieve the same combination of extremely low yield strength, low yield strength ratio, good plasticity and low temperature toughness. Therefore, it is of great practical significance to provide a steel plate for building dampers with extremely low yield strength, low yield strength ratio, good plasticity and low temperature toughness. Summary of the Invention

[0005] This application provides a low yield strength building damper steel plate and its preparation method, in order to solve the problem that existing building damper steel plates are difficult to simultaneously achieve extremely low yield strength, low yield strength ratio, good plasticity and low temperature toughness.

[0006] In a first aspect, this application provides a low-yield-strength building damper steel plate, wherein the chemical composition of the damper steel plate, by mass fraction, includes:

[0007] C≤0.0025%, Si≤0.006%, Mn:0.10%~0.15%, Ti:0.06%~0.08%, with the remainder being Fe and unavoidable impurities.

[0008] Optionally, the chemical composition of the damper steel plate, by mass fraction, further includes: P < 0.01% and S < 0.005%.

[0009] In a second aspect, this application provides a method for preparing the damper steel plate described in the first aspect, the method comprising:

[0010] The molten iron is smelted and cast to obtain a billet with the chemical composition of the damper steel plate described in the first aspect.

[0011] The billet is heated, rolled in the recrystallization zone, and cooled to obtain a damper steel plate.

[0012] Optionally, the heating temperature is 1230℃~1260℃, and the heating time is 200min~500min.

[0013] Optionally, the recrystallization zone rolling includes rolling in a one-stage rolling manner.

[0014] Optionally, the initial rolling temperature of the recrystallization zone is 1150℃~1200℃.

[0015] Optionally, the final rolling temperature of the recrystallization zone is 950℃~1050℃.

[0016] Optionally, the cooling is performed using water as the coolant.

[0017] Optionally, the final cooling temperature is 700℃~750℃.

[0018] Optionally, the cooling rate is 10℃ / s to 20℃ / s.

[0019] The technical solutions provided in this application have the following advantages compared with the prior art:

[0020] This application provides a low-yield-strength building damper steel plate. By designing the composition, the low carbon content (C below 0.0025%) reduces the cementite content in the steel plate, thereby lowering its strength. Simultaneously, the use of low Si and low Mn content weakens the solid solution effect, further reducing the steel plate's strength. Furthermore, the addition of 0.06%–0.08% Ti fixes the C content, preventing the formation of a yield plateau through C interstitial solid solution. This results in a damper steel plate with extremely low yield strength, low yield-to-strength ratio, good plasticity, and low-temperature toughness. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic flowchart illustrating the method for preparing the damper steel plate provided in this application embodiment;

[0024] Figure 2 A schematic diagram of the rolling process for the damper steel plate provided in Embodiment 1 of this application;

[0025] Figure 3 A schematic diagram of the microstructure of the damper steel plate provided in Embodiment 1 of this application;

[0026] Figure 4 This is a schematic diagram of the rolling process for the damper steel plate provided in Embodiment 2 of this application;

[0027] Figure 5 A schematic diagram of the microstructure of the damper steel plate provided in Embodiment 2 of this application;

[0028] Figure 6 A schematic diagram of the rolling process for the damper steel plate provided in Embodiment 3 of this application;

[0029] Figure 7 This is a schematic diagram of the microstructure of the damper steel plate provided in Embodiment 3 of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0032] like Figure 1 As shown in the embodiment of this application, a low yield strength damper steel plate for construction is provided. The chemical composition of the damper steel plate, by mass fraction, includes:

[0033] C≤0.0025%, Si≤0.006%, Mn:0.10%~0.15%, Ti:0.06%~0.08%, with the remainder being Fe and unavoidable impurities.

[0034] In this embodiment of the application, the positive effect of C≤0.0025% is that within this mass fraction range, the C content is kept at an ultra-low level, thereby effectively reducing the cementite content. Since a large amount of cementite can increase the strength of the steel plate, reducing the C content can effectively reduce the strength of the steel plate, thereby improving the plasticity of the steel plate.

[0035] The positive effect of Si ≤ 0.006% is that within this mass fraction range, the Si content is kept low, thereby weakening the solid solution strengthening effect of Si and reducing the strength of the steel plate.

[0036] The positive effect of a Mn mass fraction of 0.10% to 0.15% is that within this range, the Mn content is kept low, thereby weakening the solid solution strengthening effect of Mn and reducing the strength of the steel plate.

[0037] The positive effect of a Ti mass fraction of 0.06% to 0.08% is that within this range, Ti can enhance the fixation effect on C and prevent the formation of a yield plateau due to interstitial solid solution of C.

[0038] In some alternative embodiments, the chemical composition of the damper steel plate, by mass fraction, further includes: P < 0.01% and S < 0.005%.

[0039] In this embodiment of the application, the mass fractions of harmful elements P and S in the steel plate are limited, which can further control these two harmful elements, thereby improving the toughness and formability of the damper steel plate.

[0040] like Figure 1 As shown, based on a general inventive concept, this application provides a method for preparing the damper steel plate, the method comprising:

[0041] S1. The molten iron is smelted and cast to obtain a billet with the chemical composition of the damper steel plate;

[0042] S2. The billet is heated, rolled in the recrystallization zone, and cooled to obtain a damper steel plate.

[0043] In this embodiment, by heating the billet, the temperature of the subsequent recrystallization rolling is ensured to be within the recrystallization zone of the steel plate, thereby ensuring the uniformity of the steel plate grain size and controlling the degree of grain refinement. Then, cooling is used to ensure the surface quality of the steel plate, thus obtaining a steel plate product with the expected extremely low yield strength, low yield strength ratio, good plasticity and low temperature toughness.

[0044] The smelting process is as follows: KR desulfurization and converter smelting are carried out, and top and bottom combined blowing is used; vacuum treatment is carried out in LF furnace and RH furnace to reduce the content of harmful gases such as O and H, as well as C, P and S.

[0045] This method is for preparing the damper steel plate mentioned above. The specific chemical composition of the damper steel plate can be referred to in the above embodiments. Since this method adopts some or all of the technical solutions of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0046] In some optional embodiments, the heating temperature is 1230°C to 1260°C, and the heating time is 200 min to 500 min.

[0047] In this embodiment, the specific heating temperature and heating time are limited to ensure that the austenite grains are sufficiently heated and coarsened within the temperature range, and that the rolling is carried out entirely in the recrystallization zone, thereby obtaining a steel plate product with uniform grain size. If the heating temperature is too low, the final microstructure will be too fine, which will lead to excessive strength and cause some rolling to be carried out in the mixed grain zone, resulting in uneven microstructure and impact failure. If the heating temperature is too high, the final microstructure will be too coarse, which will lead to poor strength and impact toughness.

[0048] In some alternative embodiments, the recrystallization zone rolling includes rolling in a one-stage rolling manner.

[0049] In this embodiment of the application, by using a one-stage rolling method in the recrystallization zone, it can be ensured that the rolling is carried out entirely in the recrystallization zone, thereby ensuring uniform grain size after rolling.

[0050] In some alternative embodiments, the initial rolling temperature of the recrystallization zone is 1150°C to 1200°C.

[0051] In some alternative embodiments, the final rolling temperature of the recrystallization zone is 950°C to 1050°C.

[0052] In this embodiment, the starting and ending rolling temperatures of the recrystallization zone are limited to ensure that rolling is carried out in the fully recrystallized zone, ensuring uniform grain size and controlling the degree of grain refinement, thus avoiding uneven grain size and excessive strength caused by grain refinement in the non-recrystallized zone.

[0053] In some alternative implementations, the cooling is performed using water as the coolant.

[0054] In this embodiment, the specific cooling method is water cooling, which can ensure sufficient cooling of the rolled steel plate, avoid the formation of iron oxide scale on the steel plate, and at the same time ensure the grain size and uniformity of the steel plate.

[0055] In some alternative embodiments, the final cooling temperature is 700°C to 750°C.

[0056] In some alternative embodiments, the cooling rate is 10°C / s to 20°C / s.

[0057] In this embodiment, the final cooling temperature and cooling rate are limited to ensure that the cooling is carried out with a high final cooling temperature and a low cooling rate. This ensures both the surface quality of the steel plate and the grain size, thereby guaranteeing the ultra-low yield strength of the steel plate. If water cooling is not used or the final cooling temperature is too high, the iron oxide scale on the steel plate will thicken rapidly at high temperatures, which may lead to iron oxide scale blistering and indentation, affecting the surface quality of the steel plate. If the final cooling temperature is too low, the grain refinement may result in excessive strength.

[0058] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0059] Example 1

[0060] A low-yield-strength structural damper steel plate, wherein the chemical composition of the damper steel plate, by mass fraction, comprises:

[0061] C: 0.0017%, Si: 0.005%, Mn: 0.13%, Ti: 0.067%, P: 0.0072%, S: 0.004%, with the remainder being Fe and unavoidable impurities.

[0062] like Figure 1 As shown, a method for preparing low-yield-strength building damper steel plates includes:

[0063] S1. The molten iron is smelted and cast to obtain a billet with the chemical composition of the damper steel plate of the first aspect. The billet size is 237mm*2075mm*2639mm.

[0064] S2. The billet is heated, rolled in the recrystallization zone, and cooled to obtain a 12mm thick damper steel plate with specific dimensions of 12mm*2620mm*38200mm. Its microstructure is as follows: Figure 3 As shown.

[0065] The heating temperature was 1245℃, and the heating time was 306 minutes.

[0066] like Figure 2 As shown, the recrystallization zone rolling includes rolling in a one-stage rolling manner.

[0067] The initial rolling temperature for the recrystallization zone is 1191℃.

[0068] The final rolling temperature in the recrystallization zone is 953℃.

[0069] Cooling is achieved using water as the coolant.

[0070] The final cooling temperature is 737℃.

[0071] The cooling rate is 18℃ / s.

[0072] Example 2

[0073] Comparing Example 2 with Example 1, the difference between Example 2 and Example 1 is as follows:

[0074] The chemical composition of the damper steel plate, by mass fraction, includes:

[0075] C: 0.0017%, Si: 0.005%, Mn: 0.14%, Ti: 0.069%, P: 0.0099%, S: 0.007%, with the remainder being Fe and unavoidable impurities.

[0076] The billet dimensions are 237mm*1600mm*2651mm; the damper steel plate dimensions are 40mm*2500mm*8800mm, and its microstructure is as follows. Figure 5 As shown.

[0077] The heating temperature was 1238℃, and the heating time was 274 minutes.

[0078] like Figure 4 As shown, the initial rolling temperature for the recrystallization zone is 1175℃.

[0079] The final rolling temperature in the recrystallization zone is 982℃.

[0080] The final cooling temperature is 720℃.

[0081] The cooling rate is 13℃ / s.

[0082] Example 3

[0083] Comparing Example 3 with Example 1, the difference between Example 3 and Example 1 is as follows:

[0084] The chemical composition of the damper steel plate, by mass fraction, includes:

[0085] C: 0.0023%, Si: 0.006%, Mn: 0.13%, Ti: 0.071%, P: 0.0088%, S: 0.005%, with the remainder being Fe and unavoidable impurities.

[0086] The billet dimensions are 237mm*1900mm*4100mm; the damper steel plate dimensions are 45mm*2250mm*16600mm, and its microstructure is as follows. Figure 7 As shown.

[0087] The heating temperature was 1250℃, and the heating time was 281 minutes.

[0088] like Figure 6 As shown, the initial rolling temperature for the recrystallization zone is 1195℃.

[0089] The final rolling temperature in the recrystallization zone is 1050℃.

[0090] The final cooling temperature is 712℃.

[0091] The cooling rate is 11℃ / s.

[0092] The performance of the damper steel plates obtained in each embodiment was tested, and the results are shown in Table 1.

[0093] Table 1. Performance test results of each damper steel plate.

[0094]

[0095] Detailed analysis in Table 1:

[0096] Yield strength (R) p0.2 The elongation strength of steel at a non-proportional elongation rate of 0.2% indicates that the steel plate has good uniform deformation capacity and can well meet the damping requirements of the damper.

[0097] Tensile strength (R) m Tensile strength refers to the maximum stress per unit area that the specimen can withstand before it breaks. The higher the tensile strength, the better the fracture resistance of the resulting damper steel plate.

[0098] The yield strength ratio refers to the ratio of the yield strength to the tensile strength of steel. The smaller the yield strength ratio, the higher the reliability of the damper made from the steel plate.

[0099] Elongation after fracture (A) is the percentage of the total deformation ΔL of the gauge length after the specimen fractures under tension to the original gauge length L. The higher the elongation after fracture, the stronger the plasticity of the steel plate.

[0100] Impact energy at 0℃ (K) v2 This refers to the energy consumed by the pendulum impact on the sample during a notched impact test. The higher the energy of the impact, the better the low-temperature toughness of the resulting steel plate.

[0101] As can be seen from the data of the embodiments, the damper steel plate obtained in this application adopts ultra-low C content, low Si content and low Mn content, thereby weakening the solid solution effect, thereby reducing the strength of the steel plate. Furthermore, the Ti content is limited to avoid the yield plateau generated by C interstitial solid solution, and the content of harmful elements P and S is controlled to improve the toughness and formability of the damper steel plate, thereby obtaining a damper steel plate with extremely low yield strength, low yield strength ratio, good plasticity and low temperature toughness.

[0102] One or more technical solutions in the embodiments of this application have at least the following technical effects or advantages:

[0103] (1) The low yield strength building damper steel plate provided in this application adopts an ultra-low C, low Si and low Mn composition design to achieve extremely low yield strength, low yield strength ratio and good plasticity. At the same time, a large amount of Ti is added to fix C. The steel plate has no yield plate during the deformation process, and the material undergoes continuous deformation to ensure that the structure has higher safety.

[0104] (2) The method for preparing a low yield strength building damper steel plate provided in this application involves high temperature heating and rolling in a one-stage fully recrystallized zone, resulting in high production efficiency and uniform steel plate performance.

[0105] (3) The method for preparing a low yield strength building damper steel plate provided in this application adopts a process with high final cooling temperature and low cooling rate, which makes the iron oxide scale on the surface of the steel plate dense and uniform, and the surface quality good.

[0106] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0107] In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. Furthermore, in the description of this application, terms such as "comprising" and "including" mean "including but not limited to." In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. In this document, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c" or "at least one of a, b, and c" can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be a single or multiple.

[0108] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A low yield strength construction damper steel sheet, characterized by, The chemical composition of the damper steel plate is, in mass fraction: C≤0.0025%, Si≤0.006%, Mn: 0.13%~0.15%, Ti: 0.06%~0.08%, P<0.01%, S<0.005%, the rest is Fe and inevitable impurities; The preparation method of the low yield strength damper steel plate for building comprises: melting and casting the molten iron to obtain a casting blank; heating, recrystallization zone rolling and cooling the casting blank to obtain the damper steel plate; the recrystallization zone rolling comprises rolling in one stage, the opening rolling temperature of the recrystallization zone rolling is 1150~1200℃, the final rolling temperature is 950~1050℃, and the cooling speed of the cooling is 10~20℃ / s.

2. A method of producing the damper steel sheet according to claim 1, characterized by, The method comprises: melting and casting the molten iron to obtain a casting blank; heating, recrystallization zone rolling and cooling the casting blank to obtain the damper steel plate.

3. The method of claim 2, wherein, The temperature of the heating is 1230~1260℃, and the time of the heating is 200~500min.

4. The method of claim 2, wherein, The cooling is performed by using water as the cooling liquid.

5. The method of claim 2, wherein, The final cooling temperature of the cooling is 700~750℃.

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