CN110373613B - Low-yield-point steel for 100 MPa-level anti-seismic damper and preparation method thereof - Google Patents
Low-yield-point steel for 100 MPa-level anti-seismic damper and preparation method thereof Download PDFInfo
- Publication number
- CN110373613B CN110373613B CN201910717194.XA CN201910717194A CN110373613B CN 110373613 B CN110373613 B CN 110373613B CN 201910717194 A CN201910717194 A CN 201910717194A CN 110373613 B CN110373613 B CN 110373613B
- Authority
- CN
- China
- Prior art keywords
- mpa
- point steel
- low yield
- yield point
- steel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/32—Soft annealing, e.g. spheroidising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
The invention relates to a low yield point steel for a 100 MPa-level anti-seismic damper and a preparation method thereof, belongs to the technical field of metal materials, and solves the technical problems that the element proportion for fixing interstitial atoms in the existing low yield point steel is complex, and the steel-making cost is increased. The low yield point steel provided by the invention comprises the following chemical components in percentage by mass: c: 0.002-0.006 wt.%, N: 0.002-0.004 wt.%, Si: 0-0.03 wt.%, Mn: 0-0.15 wt.%, S: 0.007-0.016 wt.%, Ti: 0.08-0.10 wt.%, Al: 0.01-0.05 wt.%, P: 0-0.01 wt.%, O: 0-0.0025 wt.%, the balance being Fe and unavoidable impurities. The grain diameter of the hot-rolled annealed ferrite of the steel is 20-60 mu m, the yield strength is 80-120MPa, the tensile strength is 200-300MPa, the yield ratio is less than or equal to 0.60, the elongation is more than or equal to 50 percent, and the impact property KV is KV2(‑20℃)≥47J。
Description
Technical Field
The invention relates to the technical field of steel, in particular to low yield point steel with high S content for a 100 MPa-level anti-seismic damper and a preparation method thereof.
Background
China is an earthquake-prone area, and the number of earthquake areas (more than 7 levels) to be used as earthquake fortification is as large as 101, and the area of the earthquake areas accounts for 32.5 percent of the total area of the whole country. Based on the situation, the research and analysis of buildings in earthquake resistance are more and more emphasized by construction and designers, and the utilization of damping members to absorb earthquake energy is an important development direction in the current earthquake resistance technology, which is also called as energy-consuming earthquake resistance technology. The energy-consuming earthquake-proof technology mainly utilizes the damping component to yield firstly to absorb earthquake energy so as to reduce the influence of the earthquake on the building to the minimum, and the low-yield-point steel is the main steel for manufacturing the damping component, so the low-yield-point steel also becomes a new popular steel type in earthquake-proof materials.
The low yield point steel is produced by adopting components close to industrial pure iron, reducing the carbon content and alloy elements in the steel, has lower yield point and yield strength controlled in a lower range, has low yield ratio, elongation after fracture of over 50 percent generally, and has good hysteretic property after entering a plastic state.
The content of elements such as C, N, S and the like in the existing 100 MPa-grade low-yield-point steel plate is extremely low. The production idea of most of the steel with the extremely low yield point is to achieve the requirement of the low yield point by reducing the C, N content and fixing interstitial atoms by compositely adding micro-alloying elements (such as Ti, Nb and the like).
Disclosure of Invention
In view of the above analysis, the embodiment of the present invention aims to provide a 100 MPa-grade steel with a very low yield point and a production method thereof, so as to solve the technical problems that the element proportion for fixing interstitial atoms in the existing steel with a low yield point is complex, and the steel-making cost is increased.
The purpose of the invention is realized by the following technical scheme:
the invention discloses a low yield point steel for a 100 MPa-level anti-seismic damper, which comprises the following chemical components in percentage by mass: c: 0.002-0.006 wt.%, N: 0.002-0.004 wt.%, Si: 0-0.03 wt.%, Mn: 0-0.15 wt.%, S: 0.007-0.016 wt.%, Ti: 0.08-0.10 wt.%, Al: 0.01-0.05 wt.%, P: 0-0.01 wt.%, O: 0-0.0025 wt.%, the balance being Fe and unavoidable impurities.
Further, the addition amount of Ti is required to satisfy: ti is not less than (3.42N + 8.00C).
Further, the S comprises the following components in percentage by mass: 0.009-0.016 wt.%.
Further, the S comprises the following components in percentage by mass: 0.012-0.016 wt.%.
Further, the low yield point steel comprises the following chemical components in percentage by mass: c: 0.003-0.005 wt.%, N: 0.003-0.004 wt.%, Si: 0-0.03 wt.%, Mn: 0-0.15 wt.%, S: 0.010-0.012 wt.%, Ti: 0.08-0.10 wt.%, Al: 0.015-0.035 wt.%, P: 0-0.008 wt.%, O: 0-0.0025 wt.%, the balance being Fe and unavoidable impurities.
The invention also provides a preparation method of the low yield point steel for the 100 MPa-level anti-seismic damper, which is used for preparing the low yield point steel for the 100 MPa-level anti-seismic damper and comprises the following steps:
s1, smelting a low-yield-point steel component through a converter, an electric furnace or a vacuum induction furnace, and then carrying out continuous casting or die casting cogging;
s2, producing the blank generated in the step S1 on a medium plate hot rolling production line or a thin plate hot continuous rolling production line; the hot rolling final rolling temperature is 910-;
and S3, performing offline softening annealing after online softening annealing.
Further, in step S2, the final cold re-reddening temperature is controlled to be 700-800 ℃.
Further, in step S3, the annealing temperature of the off-line softening annealing is 700-850 ℃, and the annealing holding time is 0.5-2 h.
Further, in step S2, the finishing temperature 910-.
Further, in step S1, the ferrite grain size at the time of hot rolling annealing is 20 to 60 μm.
Compared with the prior art, the invention can realize at least one of the following beneficial effects:
(1) the high S content design is adopted on the basis of Ti microalloying to promote the formation of relatively coarse Ti at high temperature4C2S2C is fixed, the precipitation strengthening of a nanometer second phase is reduced while the solid solution strengthening is reduced, the low yield strength can be obtained, the technical idea that the traditional low-yield-point steel only utilizes TiC and NbC which are formed at lower temperature and have relatively small size to fix C is broken through, and the cost of the molten iron pretreatment process can be reduced.
(2) The addition amount of Ti element of the invention needs to be controlled as follows: ti is more than or equal to (3.42N + 8.00C); ti atoms can fix C, N-like interstitial atoms in steel, and TiN and Ti are precipitated in the steel from high temperature to low temperature in sequence in thermodynamics4C2S2And TiC, thereby reducing N, C atomic gap solid solution strengthening effect.
(3) The invention adopts low-cost single Ti microalloying to replace single Nb microalloying or Ti-Nb composite microalloying, thereby reducing the alloy cost and the difficulty in proportioning control.
In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.
Drawings
The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.
FIG. 1 is an OM photograph of a ferrite structure of a steel sheet according to example 3 of the present invention;
FIG. 2 shows Ti in a steel sheet according to example 3 of the present invention4C2S2A precipitated topography;
FIG. 3 shows a Ti steel sheet of example 3 according to the present invention4C2S2TEM images of precipitates and their spectra (Cu peaks from Cu network of samples replica with carbon film).
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.
Example 1
The invention provides a low yield point steel with high S content for a 100 MPa-level anti-seismic damper, which comprises the following chemical components in percentage by mass: c: 0.002-0.006 wt.%, N: 0.002-0.004 wt.%, Si: 0-0.03 wt.%, Mn: 0-0.15 wt.%, S: 0.007-0.016 wt.%, Ti: 0.08-0.10 wt.%, Al: 0.01-0.05 wt.%, P: 0-0.01 wt.%, O: 0-0.0025 wt.%, the balance being Fe and unavoidable impurities.
The low yield point steel for the 100 MPa-level anti-seismic damper with high S content provided by the invention mainly adopts the steps of strictly controlling the content of C, N, Si and Mn on the chemical composition and carrying out microalloying by utilizing Ti; controlling the percentage of S to be between 0.007 and 0.016 wt.% can ensure that C is fixed at high temperature, reduce the precipitation strengthening effect as much as possible while reducing the solid solution strengthening effect, control the coarsening of crystal grains to proper size through hot rolling and heat treatment processes, and finally obtain 100MPa gradeThe performance indexes of the low yield point steel are as follows: yield strength of 80-120MPa, tensile strength of 200-300MPa, yield ratio of less than or equal to 0.60, elongation of more than or equal to 50 percent, and impact property KV2(-20℃)≥47J。
Compared with the prior art, the Ti element is added on the basis of strictly controlling C, N, the addition types of other microalloy elements are reduced, and the problem that the performance is not easy to control due to uneven mixture ratio when multiple microalloy elements are added in a composite mode is solved; in addition, the S content is controlled to be 0.007 to 0.016 wt.%, so that the difficulty and the cost of S control during molten iron pretreatment and steel making can be reduced; at the same time, increasing the S content can increase Ti4C2S2Thereby reducing the amount of TiC precipitated subsequently. Due to Ti4C2S2The precipitation temperature of (2) is higher than that of TiC, so that Ti4C2S2The size is coarser than TiC, so Ti4C2S2The produced precipitation strengthening increment is smaller, and the requirement of extremely low yield strength can be better met.
The addition amount of Ti element is required to satisfy: ti is more than or equal to (3.42N + 8.00C); ti atoms can fix C, N-like interstitial atoms in steel, and TiN and Ti are precipitated in the steel from high temperature to low temperature in sequence in thermodynamics4C2S2And TiC, thereby reducing N, C atomic gap solid solution strengthening effect; in order to sufficiently fix N and C, the Ti content should be excessive. Ti4C2S2And the Ti/C mass ratio in TiC is 8 and 4, respectively. Therefore, the Ti addition amount is required to be equal to or more than (3.42N +8.00C), and therefore, the theoretical lower limit of the Ti content is 3.42 × 0.004+8.00 × 0.006 ≈ 0.06. The Ti content is not too high, and the too high Ti content causes too high and thick TiN precipitation temperature and influences the toughness; secondly, when the residual Ti content after fixation of N, C, S exceeds 0.03 wt.%, the ferrite grain size is promoted to be refined, and the solid solution strengthening effect is also exerted. Therefore, the Ti content of the steel of the present invention is controlled to 0.08 to 0.10 wt.%.
To further increase the high temperature region Ti4C2S2And reducing the formation of TiC in a subsequent relative low-temperature region, wherein the content of S element is as follows: 0.009-0.016 wt.%; due to Ti4C2S2The precipitation temperature of (2) is higher than that of TiC, so that Ti4C2S2The size is coarser than TiC, therefore, Ti4C2S2The resulting precipitation strengthening gain is smaller, which may better meet the requirements of very low yield strength. Ti produced by increasing S content of steel of the invention4C2S2Is elliptical, has a size below 1 μm, and has no significant harm to plasticity and toughness.
Illustratively, the chemical components and mass percentages of the steel with the extremely low yield point are as follows: c: 0.003-0.005 wt.%, N: 0.003-0.004 wt.%, Si: 0-0.03 wt.%, Mn: 0-0.15 wt.%, S: 0.010-0.012 wt.%, Ti: 0.08-0.10 wt.%, Al: 0.015-0.035 wt.%, P: 0-0.008 wt.%, O: 0-0.0025 wt.%, the balance being Fe and unavoidable impurities.
Example 2
The invention also provides a preparation method of the low yield point steel for the 100 MPa-level anti-seismic damper, which is used for producing the steel for the 100 MPa-level anti-seismic damper provided by the embodiment 1, and the production method comprises the following steps:
the preparation of the billet before rolling the low yield point steel adopts the smelting of a conventional converter, an electric furnace or a vacuum induction furnace, and then adopts a continuous casting or die casting cogging mode; and rolling the low-yield-point billet into a finished product in a medium plate hot rolling production line or a thin plate hot continuous rolling production line.
It should be noted that the hot rolling finishing temperature of the invention is 910-; when the hot finishing temperature is higher than 950 ℃, the ferrite grain diameter is difficult to control less than 60 μm. The average cooling speed after hot rolling is more than or equal to 2 ℃/s, so that a ferrite structure with the grain diameter of less than 60 mu m can be obtained, the cooling speed is continuously increased, and the effect of further refining the grains is not obvious. Therefore, the hot rolling finishing temperature is 910 ℃ and 950 ℃, and laminar cooling with the average cooling speed of 2-10 ℃/s is adopted after rolling; in addition, when the final cooling and red returning temperature is controlled to be between 700 and 800 ℃, the ferrite phase transformation can be fully completed, and meanwhile, the online softening annealing is carried out by utilizing high-temperature waste heat. Microscopically, the softening annealing can further eliminate dislocations in the ferrite structure and fix interstitial atoms such as C, N sufficiently.
In order to further reduce the yield strength, improve the plasticity and homogenize the performance, the off-line softening annealing can be carried out after the hot rolling, the annealing temperature is 700-850 ℃, and the annealing heat preservation time is 0.5-2 h. The annealing temperature is lower than 700 ℃, the heat preservation time is less than 0.5h, and the improvement effect is not obvious; the annealing temperature is higher than 850 ℃, the holding time is longer than 2 hours, the process is not economical, and the continuous temperature rise to be higher than 910 ℃ can lead to the re-dissolution of ferrite-austenite phase ratio, C, N, Ti and the like.
Specifically, the grain diameter of the hot-rolled annealed ferrite is 20 to 60 μm, particularly 30 to 50 μm; when the grain diameter of the hot-rolled annealed ferrite is less than 20 mu m, the yield strength of the steel plate is more than 120MPa, and the requirement of the steel of the invention on 100MPa level is exceeded; when the grain diameter of the hot-rolled annealed ferrite is more than 60 mu m, the low-temperature toughness of the steel plate does not meet KV2The requirement that (-20 ℃) is more than or equal to 47J, therefore, the grain diameter of hot-rolled annealed ferrite is controlled between 20 and 60 mu m.
It should be noted that the action and the proportion of each element of the invention are as follows:
c: too high a content lowers the elongation of the steel and increases the yield strength. In order to obtain extremely low yield strength, the invention adopts the design of extremely low C, but simultaneously takes the production cost and difficulty into consideration, and controls the content of the C to be 0.002-0.006 wt.%.
N: the free N atoms increase the yield strength of the steel. In order to reduce the concentration of free N atoms, it is necessary to add a microalloying element such as Ti. If the N content is higher, large-grained TiN is more likely to be liquated out, and the toughness is affected. Therefore, the lower the N content, the better, and the content thereof is controlled to 0.002 to 0.004 wt.% in consideration of both the steel-making cost and the workability.
Si: the steel contains deoxidizing elements, which are one of the solid solution strengthening elements for improving the strength of the steel, and the elongation is reduced, and the content of the deoxidizing elements is controlled to be less than 0.03 wt.%.
Mn: since the steel contains a common reinforcing element and the yield strength is increased by solid solution strengthening to lower the elongation, the composition should be as low as possible and the content thereof should be controlled to 0.15 wt.% or less in the present composition design.
S: is a harmful element in common steel, and can reduce the toughness and plasticity of the steel. The invention can increase the S content of the low yield point steel and can increase the Ti content of the high temperature zone4C2S2Thereby reducing the amount of TiC generated in the subsequent relatively low temperature region. Due to Ti4C2S2The precipitation temperature of the alloy is higher than that of TiC, so the former is thicker than the latter in size, the precipitation strengthening increment generated by the former is smaller, and the requirement of extremely low yield strength can be better met. Ti produced by increasing S content of steel of the invention4C2S2Is elliptical, has a size below 1 μm, and has no significant harm to plasticity and toughness. The S content of the inventive steel is in the range of 0.007-0.016 wt.%; ti when the S content is less than 0.007 wt%4C2S2The effect of precipitating and fixing C at high temperature is not obvious; the upper limit of the S content is 0.016 wt.% of Ti4C2S2The upper limit of the C content and the central C, S atomic ratio are determined together.
Ti: fixing C, N equal-gap atoms in steel, and thermally precipitating TiN and Ti in sequence from high temperature to low temperature4C2S2And TiC, thereby reducing N, C atomic gap solid solution strengthening effect. In order to sufficiently fix N and C, the Ti content should be excessive. Ti4C2S2And Ti in TiC: the C mass ratios were 8 and 4, respectively. Therefore, the addition amount of Ti is required to satisfy Ti ≥ 3.42N + 8.00C. Therefore, the lower limit of the Ti content is 3.42X 0.004+ 8.00X 0.006 ≈ 0.06. The Ti content is not too high, and the too high Ti content causes too high and thick TiN precipitation temperature and influences the toughness; secondly, if the residual Ti content after fixation of N, C, S exceeds 0.03 wt.%, the ferrite grain size is promoted to be refined and the solid solution strengthening is also performed. Therefore, the Ti content of the steel of the present invention needs to be controlled to 0.06-0.10 wt.%.
Al: strong deoxidizing element for deep deoxidizing. The content of the sodium chloride in the invention is controlled to be 0.01-0.05 wt.%. Too high Al will increase the alloy cost and process difficulty.
P: the yield strength of the steel is improved, and the toughness of the steel is reduced. The present invention is required to have a content as low as possible, because it is required to control not only low yield strength but also excellent low-temperature toughness. The content of the catalyst is controlled to be below 0.01 wt.% in consideration of the comprehensive process cost.
O: impurity elements in the steel reduce the toughness and plasticity of the steel. The invention requires that its content is as low as possible. The content of the catalyst is controlled to be below 0.0025 wt.% in consideration of the comprehensive process cost.
Example 3
The embodiment provides four kinds of steel with different chemical components and mass percentages, and as shown in table 1, the production method for preparing the low yield point steel for the 100 MPa-level anti-seismic damper provided in the embodiment 2 comprises the following steps:
s1, carrying out hot rolling at a final rolling temperature of 910-; wherein the ferrite grain diameter during hot rolling annealing is 20-60 μm;
and S2, performing off-line softening annealing after the on-line softening annealing, wherein the annealing temperature of the off-line softening annealing is 700-850 ℃, and the annealing heat preservation time is 0.5-2 h.
The steels having different chemical compositions in table 1 were subjected to hot rolling, cooling and off-line annealing treatment using the above method, and the treatment conditions for each group of steels are shown in table 2, thereby obtaining the mechanical property data of the steels in table 3.
Table 1 chemical composition and mass percent (wt.%) of different steel grades
TABLE 2 production process parameters of different numbered steels and their corresponding ferrite grain diameters
TABLE 3 mechanical Property test results for steels of different numbers
Wherein OM photograph of ferrite structure of steel sheet with number 1 is shown in figure 1; ti in Steel sheet No. 14C2S2The precipitated topography is shown in figure 2; steel sheet Ti of No. 14C2S2The TEM image and the spectrum (Cu peak is from Cu network of the sample with carbon film replica) of the precipitate are shown in FIG. 3.
As can be seen from table 3, the lower the C content and the higher the S, Ti content in the 4 numbered steels in example 3 are, the better the control is to obtain the low yield strength, compared with the comparative example, wherein the latter fully represents the core technical idea of the Ti — S synergistic effect of reducing the total effect of C solid solution and nano second phase precipitation strengthening of the steel of the present invention. When the carbon content is high (0.006%), the addition of Ti and S with the upper limit content is adopted, and the Mn content is reduced, so that the ideal low yield strength can be obtained.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (8)
1. The low yield point steel for the 100 MPa-level anti-seismic damper is characterized by comprising the following chemical components in percentage by mass: c: 0.002-0.006 wt.%, N: 0.002-0.004 wt.%, Si: 0.01-0.02 wt.%, Mn: 0-0.15 wt.%, S: 0.0124-0.016 wt.%, Ti: 0.08-0.10 wt.%, Al: 0.01-0.05 wt.%, P: 0.0067-0.01 wt.%, O: 0-0.0025 wt.%, the balance Fe and unavoidable impurities;
the addition amount of Ti is required to satisfy: ti is more than or equal to (3.42N + 8.00C);
the preparation method of the low yield point steel for the 100 MPa-level anti-seismic damper comprises the following steps:
s1, smelting a low-yield-point steel component through a converter, an electric furnace or a vacuum induction furnace, and then carrying out continuous casting or die casting cogging;
s2, producing the blank generated in the step S1 on a medium plate hot rolling production line or a thin plate hot continuous rolling production line; the hot rolling final rolling temperature is 910-;
s3, performing off-line softening annealing after the on-line softening annealing, wherein the annealing temperature of the off-line softening annealing is 700-850 ℃, and the annealing heat preservation time is 0.5-2 h; the grain diameter of hot-rolled annealed ferrite is 20-60 mu m;
the low yield point steel for the 100 MPa-level anti-seismic damper has the following performance indexes: yield strength of 80-120MPa, tensile strength of 200-300MPa, yield ratio of less than or equal to 0.60, elongation of more than or equal to 50 percent, and impact property KV at minus 20 DEG C2≥47J。
2. The low yield point steel for the 100 MPa-level anti-seismic damper according to claim 1, wherein S comprises the following components in percentage by mass: 0.0124-0.0156 wt.%.
3. The low yield point steel for the 100 MPa-level anti-seismic damper according to claim 1, which is characterized by comprising the following chemical components in percentage by mass: c: 0.003-0.005 wt.%, N: 0.003-0.004 wt.%, Si: 0.01-0.02 wt.%, Mn: 0-0.15 wt.%, S: 0.0124-0.016 wt.%, Ti: 0.08-0.10 wt.%, Al: 0.015-0.035 wt.%, P: 0.0067-0.008 wt.%, O: 0-0.0025 wt.%, the balance being Fe and unavoidable impurities.
4. A method for preparing a low yield point steel for a 100 MPa-level anti-seismic damper, which is used for preparing the low yield point steel for the 100 MPa-level anti-seismic damper as defined in any one of claims 1 to 3, and comprises the following steps:
s1, smelting a low-yield-point steel component through a converter, an electric furnace or a vacuum induction furnace, and then carrying out continuous casting or die casting cogging;
s2, producing the blank generated in the step S1 on a medium plate hot rolling production line or a thin plate hot continuous rolling production line; the hot rolling final rolling temperature is 910-;
s3, performing off-line softening annealing after the on-line softening annealing, wherein the annealing temperature of the off-line softening annealing is 700-850 ℃, and the annealing heat preservation time is 0.5-2 h; the grain diameter of the hot-rolled annealed ferrite is 20-60 mu m.
5. The preparation method of the low yield point steel for the 100 MPa-level anti-seismic damper as claimed in claim 4, wherein in step S2, the final cold-reversion temperature is controlled to be 720-793 ℃.
6. The preparation method of the low yield point steel for the 100 MPa-level anti-seismic damper as claimed in claim 5, wherein in the step S3, the annealing temperature of the off-line softening annealing is 800-850 ℃, and the annealing holding time is 0.5-2 h.
7. The method for preparing the low yield point steel for the 100 MPa-level anti-seismic damper as claimed in claim 6, wherein in the step S2, the final rolling temperature is 915-948 ℃, and laminar cooling with the average cooling speed of 2-10 ℃/S is adopted after hot rolling.
8. The method for preparing a low yield point steel for a 100 MPa-grade anti-seismic damper according to any one of claims 4 to 7, wherein the ferrite grain diameter in the hot rolling annealing process in step S1 is 29 to 58 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910717194.XA CN110373613B (en) | 2019-08-05 | 2019-08-05 | Low-yield-point steel for 100 MPa-level anti-seismic damper and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910717194.XA CN110373613B (en) | 2019-08-05 | 2019-08-05 | Low-yield-point steel for 100 MPa-level anti-seismic damper and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110373613A CN110373613A (en) | 2019-10-25 |
| CN110373613B true CN110373613B (en) | 2021-05-07 |
Family
ID=68258144
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910717194.XA Active CN110373613B (en) | 2019-08-05 | 2019-08-05 | Low-yield-point steel for 100 MPa-level anti-seismic damper and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110373613B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101392350A (en) * | 2007-09-18 | 2009-03-25 | 宝山钢铁股份有限公司 | Extremely low yield point steel plate and production method thereof |
| CN101705433A (en) * | 2009-09-29 | 2010-05-12 | 燕山大学 | 196 DEG C below zero ultralow-temperature quake-proof structural steel |
| CN104087830A (en) * | 2014-07-15 | 2014-10-08 | 首钢总公司 | Method for preparing 160MPa grade low-yield-point building aseismicity steel |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101775542B (en) * | 2010-03-09 | 2012-05-30 | 武汉钢铁(集团)公司 | Quake-proof construction steel with yield strength of 100MPa and production method thereof |
| CN101775541B (en) * | 2010-03-09 | 2012-01-11 | 武汉钢铁(集团)公司 | Quake-proof construction steel with yield strength of 160MPa and production method thereof |
| CN103266213A (en) * | 2013-06-11 | 2013-08-28 | 鞍钢股份有限公司 | Production method of ultralow-yield-point anti-seismic steel |
| CN104087831B (en) * | 2014-07-15 | 2017-03-01 | 首钢总公司 | A kind of manufacture method of 100MPa rank low-yield building aseismicity steel |
| CN104264054B (en) * | 2014-09-19 | 2017-02-22 | 宝山钢铁股份有限公司 | 550MPa-level high-temperature resistant pipeline steel and preparation method thereof |
| CN107881427B (en) * | 2016-09-30 | 2020-09-25 | 宝山钢铁股份有限公司 | Low-yield-strength aluminum-coated substrate with excellent plasticity |
| CN106987771B (en) * | 2017-04-20 | 2018-11-09 | 唐山钢铁集团有限责任公司 | A kind of extremely low yield strength steel plate and its production method |
| JP6537659B1 (en) * | 2018-03-28 | 2019-07-03 | 日鉄ステンレス株式会社 | Martensitic stainless hot rolled steel sheet, method of manufacturing disc brake rotor using the same |
-
2019
- 2019-08-05 CN CN201910717194.XA patent/CN110373613B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101392350A (en) * | 2007-09-18 | 2009-03-25 | 宝山钢铁股份有限公司 | Extremely low yield point steel plate and production method thereof |
| CN101705433A (en) * | 2009-09-29 | 2010-05-12 | 燕山大学 | 196 DEG C below zero ultralow-temperature quake-proof structural steel |
| CN104087830A (en) * | 2014-07-15 | 2014-10-08 | 首钢总公司 | Method for preparing 160MPa grade low-yield-point building aseismicity steel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110373613A (en) | 2019-10-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109628836B (en) | High-strength anti-seismic fire-resistant steel for building structure and preparation method thereof | |
| CN100507055C (en) | Yield strength 700MPa grade atmospheric corrosion resistant steel and method for manufacturing same | |
| CN108796363B (en) | High-surface-quality aluminum-coated substrate steel suitable for large deformation and stamping and production method thereof | |
| CN113234995B (en) | Ultra-thick hot-rolled H-shaped steel with yield strength of 600MPa and production method thereof | |
| CN112877606A (en) | Ultrahigh-strength full-austenite low-density steel and preparation method thereof | |
| CN110306114B (en) | Corrosion-resistant and fire-resistant structural steel with yield strength of 460MPa and production method thereof | |
| CN104498821B (en) | Medium-manganese high-strength steel for automobiles and production method thereof | |
| CN109972042B (en) | Low-temperature-resistant corrosion-resistant H-shaped steel with yield strength of 800MPa and preparation method thereof | |
| CN109652733B (en) | 690 MPa-grade super-thick steel plate and manufacturing method thereof | |
| CN111057965B (en) | Ocean engineering steel with low yield ratio and preparation method thereof | |
| CN112501496B (en) | On-line quenching type double-phase low-yield-ratio steel plate and production method thereof | |
| CN104947005A (en) | Large-thickness and high-performance hydroforming 14Cr1MoR steel plate and production method thereof | |
| CN102312158A (en) | Nb, Ti alloyed low-carbon high-intensity high-plasticity TWIP steel and preparation method thereof | |
| CN105624562A (en) | Steel for ultra-high-strength sucker rod and production method thereof | |
| CN111187977B (en) | 690 MPa-grade anti-seismic, corrosion-resistant and fire-resistant medium-thickness plate steel and manufacturing method thereof | |
| CN114231765A (en) | Preparation method and application of high-temperature alloy bar | |
| CN108754335B (en) | A kind of the welding structure fire-resistant and weather-resistant steel and production method of yield strength >=550MPa | |
| CN103484764A (en) | Ti precipitation strengthening type ultra-high-strength hot rolling thin plate and production method thereof | |
| CN101748327B (en) | High-performance steel plate for building structure and manufacturing method thereof | |
| CN102650017A (en) | Hot-rolled steel plate and manufacturing method thereof | |
| CN102011060A (en) | 700MPa-grade cold rolled steel plate with high weather resistance and preparation method thereof | |
| CN110373613B (en) | Low-yield-point steel for 100 MPa-level anti-seismic damper and preparation method thereof | |
| CN104561792B (en) | V-N alloyed high-strength steel plate and manufacturing method thereof | |
| CN102021478B (en) | High-toughness high-weather-resistance bridge steel and plate coil rolling method thereof | |
| CN111154962B (en) | Anti-seismic corrosion-resistant refractory steel and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |