Hot-rolled steel plate with anti-seismic function and manufacturing method thereof

Abstract

The invention belongs to the technical field of metal materials, and particularly relates to a hot-rolled steel plate with an anti-seismic function, which comprises the following chemical components in percentage by mass: less than or equal to 0.01% of C, less than or equal to 0.05% of Si, 0.5-0.8% of Cu, 2-4% of Cr, 2-3% of Al, less than or equal to 0.01% of S, less than or equal to 0.018% of P, less than or equal to 0.005% of N and the balance of Fe and inevitable impurities. The manufacturing method comprises the following steps: heating a cast ingot, and rolling to obtain a hot-rolled steel plate, namely (1) heating the cast ingot with qualified components to 1000 + / -50 DEG C in a heating furnace, and preserving heat for 2 + / -0.5 hours; and (2) common rolling and water cooling are adopted, the initial rolling temperature is 1000 + / -50 DEG C, the final rolling temperature is 800 + / -20 DEG C, water cooling is conducted to 560 + / -20 DEG C, coiling is simulated, heat preservation is conducted for 3 + / -0.5 h, and furnace cooling is conducted to the room temperature. According to the performance indexes of the hot-rolled steel plate, the yield strength is larger than or equal to 400 MPa, the tensile strength is larger than or equal to 600 MPa, the percentage elongation after fracture A50 is larger than or equal to 25%, and the damping value delta is larger than or equal to 0.08

Description

Technical Field

[0001] The invention relates to the technical field of metal materials, and in particular to a hot-rolled steel plate with earthquake-resistant function and a manufacturing method thereof. Background Art

[0002] As people's requirements for the comprehensive quality of buildings and the environmental friendliness of electromechanical products are increasing, the demand of steel product users for steel is no longer simply high strength and high toughness. Some special properties such as vibration reduction performance and certain corrosion resistance are gradually being valued by steel material users. Structural and functional integrated steel materials have certain other functions while having the properties of structural materials, such as vibration reduction, corrosion resistance, and wave absorption performance. In order to meet the growing requirements of users for the special properties of steel materials, structural and functional integrated steel materials will surely become an important development direction for the next generation of steel materials.

[0003] Existing patent CN201811437499 Fe-Mn-Si-Ni-C series elastic-plastic damping steel and its manufacturing method and application, the chemical composition mass percentage in the invention is: 20.0%≤Mn≤34.0%, 3.5%≤Si≤6.0%, 0.1%≤Ni≤5.0%, 0.005%≤C<0.15%, P≤0.02%, S≤0.01%, N≤0.02%, the rest is Fe and unavoidable impurity elements, among which the mass percentage of Mn, N and C elements must also satisfy the following relationship: Mn+1.6Ni+52C≥32% and Mn+2Ni≤37%. The elastic-plastic damping steel is prepared by the production process of melting, hot rolling, hot rolling and annealing or melting, hot rolling, pickling, cold rolling, cold rolling and annealing. The steel alloy system is complex, the total amount of alloy elements is greater than 20%, and the cost is relatively high.

[0004] The existing patent CN201810419921 is a high-performance elastic-plastic damping steel and its manufacturing method and application. The mass percentage of the chemical composition of the invented steel is: 24%≤Mn≤32%, 3.5%≤Si≤6.0%, 1.0%<Al<2.5%, 0.005%≤C≤0.1%, P≤0.02%, S≤0.03%, N≤0.02%, and the rest is Fe and unavoidable impurity elements, among which the Si and Al contents must also satisfy the following relationship: 2.0. With high alloy design, the total alloy amount exceeds 26%, the cost is high, and it is difficult to achieve continuous casting production.

[0005] The existing CN201710549325 is a composite low alloy damping steel containing Nb and its preparation method, the weight percentage of its chemical composition is: ≤0.15% carbon, ≤0.2% silicon, 0.5-2.0% manganese, 0.2-0.6% sulfur, 0.01-0.06% niobium, Mn / S ratio is greater than 3.50, but not more than 4.50, and the rest is iron and inevitable trace chemical elements. The invented steel is an alloy design containing ultra-high sulfur, which improves the damping performance of the steel, but also seriously deteriorates the cold and hot processing performance and comprehensive mechanical properties of the steel.

[0006] Existing patent CN202210856214.3 A preparation method of high-carbon damping and vibration-damping steel and its melting and casting device, adopts a composite casting method combining vacuum induction melting and centrifugal casting, uses composite shear flow technology, combined with subsequent controlled rolling, controlled cooling and heat treatment technology, to shorten the heat treatment time of high-carbon damping and vibration-damping steel, including the following steps: (1) preparing the raw materials required for smelting, the chemical composition mass percentage of high-carbon damping and vibration-damping steel is: C ≥ 1.2%, Si: 1.5%-1.7%, Mn: 0.20%-0.22%, Ni: 2.15%-2.25%, Al: 0.25%-0.27%, balance: Fe; (2 ) Put the raw materials into the crucible of the smelting system, embed the casting mold into the centrifugal barrel, fill the refractory insulation material between the casting mold and the centrifugal barrel, and preheat the casting mold; (3) Use the induction smelting process to heat and melt the raw materials in the crucible and keep them warm. After the insulation is completed, pour the alloy melt into the casting mold; (4) Turn on the motor to drive the bottom centrifugal disk, drive the centrifugal barrel, and the centrifugal barrel and the bottom centrifugal disk move at a set speed ratio until the alloy is completely solidified and then the ingot is taken out; (5) After the ingot is homogenized at high temperature, it is rolled by controlling the temperature of the rolling process; (6) The rolled plate is subjected to isothermal heat treatment and then furnace cooling treatment to graphitize the rolled plate, that is, the high-carbon damping and vibration-reducing steel is obtained. The core technology is to use the role of Ni and Al in promoting graphitization, and to graphitize the carbon of high-carbon steel through a complex heat treatment process, thereby improving its damping performance. The alloy cost and process cost are high.

[0007] The existing patent CN86102543 is an iron-chromium multi-element mute vibration damping steel and its manufacturing method. The present invention is an iron-chromium mute vibration damping steel and its manufacturing method, which belongs to the field of iron-based alloys and their smelting. The present invention adds one, two, or three of Si-Ca alloy, Ti-Fe alloy, mixed rare earth metal or its alloy (rare earth-magnesium, rare earth-calcium, rare earth-magnesium-silicon alloy, etc.) during the smelting process to remove non-metallic impurities in the steel and realize non-vacuum smelting. In addition to Fe and Cr, the alloy composition of the present invention also contains three or more components of Mo, Si, Cu, Ti, Mn, C and mixed rare earth. The present invention can be used on various electromechanical products with greater vibration and noise hazards. The alloy system of the invention is complex and the cost is high. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a hot-rolled steel plate with anti-seismic function and a manufacturing method thereof, which has high mechanical properties, meets the requirements of structural materials and has excellent damping performance.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A hot-rolled steel plate with anti-seismic function, the chemical composition mass percentage is: C≤0.01%, Si≤0.05%, Cu: 0.5%-0.8%, Cr: 2%-4%, Al: 2%-3%, S≤0.01%, P≤0.018%, N≤0.005%, and the balance is Fe and inevitable impurities.

[0011] A hot-rolled steel plate with earthquake resistance, performance indicators: yield strength ≥ 400MPa, tensile strength ≥ 600MPa, elongation after fracture A 50 ≥25%, damping value δ≥0.08.

[0012] The components and main functions of the steel plate in the present invention are:

[0013] C: Although carbon is the most important solid solution strengthening element in steel, solid solution carbon will significantly reduce the damping performance of the steel plate, and further reducing the C content will greatly increase the smelting difficulty and process cost. The optimal range of carbon in the present invention is ≤0.01%.

[0014] Si: is a common element in steel, which can improve the strength of steel but reduce the plasticity of steel. Further reducing the Si content will increase the metallurgical cost. The silicon content of the present invention is ≤0.05%.

[0015] Cu: Copper has both solid solution strengthening and precipitation strengthening effects. The copper precipitation phase can also improve the damping performance of steel. However, too high a copper content will increase surface defects of the ingot and hot-rolled steel plate. At the same time, the maximum solid solubility of Cu in ferrite is about 0.8%, so the Cu content of the present invention is set to 0.5%-0.8%.

[0016] Cr: It plays a role of solid solution strengthening and can improve the corrosion resistance, and can also improve the damping performance of steel. However, too high Cr makes the processing and formability of steel worse. The Cr content of the present invention is Cr: 2%-4%.

[0017] Al: Aluminum can inhibit the precipitation of cementite, fix nitrogen in steel, play a role in refining grains to a certain extent, and solid-solution aluminum promotes the formation of ferrite, indirectly improving damping performance. The range of aluminum in the present invention is Al: 2%-3%.

[0018] P: Although phosphorus can improve the strength of the steel sheet, it will seriously deteriorate the cold forming performance of the steel, especially the secondary forming performance, so its upper limit is set to ≤0.018%.

[0019] S: Sulfur is a harmful element in steel. It will form manganese sulfide to reduce the performance of the steel plate. Therefore, the lower the content, the better. The upper limit is set at 0.01%.

[0020] N: As a harmful impurity, it deteriorates the plasticity of steel and reduces the damping performance, so the upper limit is made 0.005%.

[0021] A method for manufacturing a hot-rolled steel plate with an anti-seismic function, wherein the hot-rolled steel plate is obtained by rolling after heating the ingot, and the specific steps are as follows:

[0022] (1) Heating process: Heat the ingot with qualified composition to 1000±50℃ in a heating furnace and keep it at this temperature for 2±0.5 hours;

[0023] (2) Rolling process: Ordinary rolling + water cooling, starting rolling temperature 1000±50℃, final rolling temperature 800±20℃, water cooling to 560℃±20℃, coiling, heat preservation for 3±0.5 hours, and cooling to room temperature with the furnace.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention improves the strength of steel and improves damping performance by adding Cr and Al elements, and improves the strength of steel by using the precipitation strengthening effect of Cu element, so that the hot-rolled steel plate has high damping performance and good mechanical properties. The composite addition of Cr, Al and Cu can also effectively improve the corrosion resistance of steel.

[0026] 2. The hot-rolled steel plate has a single ferrite structure, yield strength ≥ 400MPa, tensile strength ≥ 600MPa, elongation after fracture A 50 ≥25%, widely meeting the performance requirements of steel for automobiles, home appliances, construction and mechanical equipment.

[0027] 3. The damping value of the steel plate is δ≥0.08, which is more than 10 times that of ordinary steel materials, reducing the risk of mechanical vibration of automobiles and home appliances and resonance instability of buildings.

[0028] The use of the steel plate of the present invention can effectively reduce the noise generated by automobiles and mechanical equipment, and reduce the risk of structural instability of buildings due to resonance with wind waves. DETAILED DESCRIPTION

[0029] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. The reference to "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] A hot-rolled steel plate with anti-seismic function, the chemical composition mass percentage is: C≤0.01%, Si≤0.05%, Cu: 0.5%-0.8%, Cr: 2%-4%, Al: 2%-3%, S≤0.01%, P≤0.018%, N≤0.005%, and the balance is Fe and inevitable impurities.

[0031] A hot-rolled steel plate with anti-seismic function, with performance indicators: yield strength ≥400MPa, tensile strength ≥600MPa, elongation after fracture A50 ≥25%, and damping value δ ≥0.08.

[0032] A method for manufacturing a hot-rolled steel plate with a seismic resistance function, wherein the hot-rolled steel plate is obtained by heating the ingot and rolling it, and the specific steps are as follows:

[0033] (1) Heating process: Heat the ingot with qualified composition to 1000±50℃ in a heating furnace and keep it at this temperature for 2±0.5 hours to make the alloy elements fully dissolved and the composition uniform.

[0034] (2) Rolling process: Ordinary rolling + water cooling is adopted, and the final rolling temperature is 800±20℃, so as to ensure that the microstructure after final rolling is a single ferrite with larger grain size. The larger ferrite size is a necessary condition for the high damping value of the steel plate under the ferromagnetic mechanism. At the same time, it can also ensure that the Cu element is fully dissolved; water cooling to 560℃±20℃, the faster cooling rate can inhibit the non-uniform precipitation of copper in the steel in a larger size during the cooling process, and reduce the precipitation strengthening effect of copper, coiling at 560℃±20℃, keeping warm for 3±0.5 hours, and cooling to room temperature with the furnace, so as to ensure that Cu is fully and uniformly precipitated at a lower temperature, increase the probability of intersection between dislocation and Cu precipitation during deformation, and improve the strength and damping performance of the steel. Slow cooling with the furnace can also reduce the stress of the steel plate at room temperature and improve the damping performance of the steel plate. Al can increase the ferrite transformation temperature, increase the grain size, facilitate the movement of the magnetic domain wall, and improve the damping performance of the steel plate. Compared with conventional bulk steel, the grain size of the steel of the present invention can be as low as level 4.

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0036] Example:

[0037] 200kg electric furnace vacuum smelting, casting into 80kg steel ingot, and then heating and rolling. After cutting the head and tail of the 80kg ingot with qualified composition, heat it to 1000±50℃℃ and keep it warm for 2±0.5 hours. The hot rolling final rolling temperature is 800±20℃, water-cooled to 560℃±20℃ for coiling, kept warm for 3±0.5 hours, and cooled to room temperature with the furnace.

[0038] The specific compositions, process systems and properties of the steel plates of the six embodiments of the present invention are shown in Tables 1-3.

[0039] Table 1: Chemical composition of the examples (wt, %)

[0040] serial number C Si Cr P S Al Cu Example 1 0.01 0.04 2.8 0.016 0.007 2.2 0.8 Example 2 0.008 0.05 2.0 0.014 0.006 3.0 0.5 Example 3 0.005 0.03 2.9 0.015 0.01 2.7 0.72 Example 4 0.01 0.05 3.5 0.008 0.005 2.1 0.62 Example 5 0.009 0.04 4.0 0.012 0.007 2.8 0.72 Example 6 0.007 0.04 3.1 0.011 0.005 2.6 0.63

[0041] Table 2: Hot rolling process parameters of the embodiment

[0042]

[0043] Table 3: Mechanical properties parameters of the examples

[0044]

[0045]

[0046] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and basic spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hot-rolled steel plate with earthquake resistance, characterized in that: The steel plate has a single ferrite structure, and the chemical composition mass percentage is: C≤0.01%, Si≤0.05%, Cu: 0.5%-0.8%, Cr: 2%-4%, Al: 2%-3%, S≤0.01%, P≤0.018%, N≤0.005%, and the balance is Fe and unavoidable impurities.

2. The hot-rolled steel plate with earthquake resistance according to claim 1, characterized in that: Performance indicators: yield strength ≥400MPa, tensile strength ≥600MPa, elongation after fracture A 50 ≥25%, damping value δ≥0.

08.

3. A method for manufacturing a hot-rolled steel plate with earthquake resistance according to claim 1, characterized in that: The ingot is heated and then rolled to obtain a hot-rolled steel plate. The specific steps include: (1) Heating process: Heat the ingot with qualified composition to 1000±50℃ in a heating furnace and keep it at this temperature for 2±0.5 hours; (2) Rolling process: Ordinary rolling + water cooling, starting rolling temperature 1000±50℃, final rolling temperature 800±20℃, water cooling to 560℃±20℃ to simulate coiling, keeping warm for 3±0.5 hours, and cooling to room temperature with the furnace.

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