CN116657058A - High-strength steel bar with excellent corrosion resistance and earthquake resistance and preparation method thereof - Google Patents
High-strength steel bar with excellent corrosion resistance and earthquake resistance and preparation method thereof Download PDFInfo
- Publication number
- CN116657058A CN116657058A CN202310646597.6A CN202310646597A CN116657058A CN 116657058 A CN116657058 A CN 116657058A CN 202310646597 A CN202310646597 A CN 202310646597A CN 116657058 A CN116657058 A CN 116657058A
- Authority
- CN
- China
- Prior art keywords
- steel
- steel bar
- corrosion resistance
- percent
- excellent corrosion
- 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.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 125
- 239000010959 steel Substances 0.000 title claims abstract description 125
- 230000007797 corrosion Effects 0.000 title claims abstract description 44
- 238000005260 corrosion Methods 0.000 title claims abstract description 44
- 238000002360 preparation method Methods 0.000 title claims abstract description 19
- 238000004519 manufacturing process Methods 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims abstract description 9
- 239000000126 substance Substances 0.000 claims abstract description 6
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 239000000463 material Substances 0.000 claims abstract description 5
- 238000010438 heat treatment Methods 0.000 claims description 30
- 238000005096 rolling process Methods 0.000 claims description 26
- 239000011241 protective layer Substances 0.000 claims description 20
- 230000000171 quenching effect Effects 0.000 claims description 18
- 238000010791 quenching Methods 0.000 claims description 17
- 238000005496 tempering Methods 0.000 claims description 15
- 238000003723 Smelting Methods 0.000 claims description 12
- 239000010410 layer Substances 0.000 claims description 11
- 229910000859 α-Fe Inorganic materials 0.000 claims description 11
- 238000001816 cooling Methods 0.000 claims description 10
- 238000007670 refining Methods 0.000 claims description 10
- 238000005266 casting Methods 0.000 claims description 7
- 239000013078 crystal Substances 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 6
- 239000002994 raw material Substances 0.000 claims description 6
- 238000010079 rubber tapping Methods 0.000 claims description 6
- 239000002893 slag Substances 0.000 claims description 6
- 238000009628 steelmaking Methods 0.000 claims description 6
- 229910001562 pearlite Inorganic materials 0.000 claims description 5
- 238000009749 continuous casting Methods 0.000 claims description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims description 4
- 238000005275 alloying Methods 0.000 claims description 3
- 238000007664 blowing Methods 0.000 claims description 3
- 239000011261 inert gas Substances 0.000 claims description 3
- 238000007689 inspection Methods 0.000 claims description 3
- 238000005070 sampling Methods 0.000 claims description 3
- 229910052717 sulfur Inorganic materials 0.000 claims description 3
- 238000010891 electric arc Methods 0.000 claims description 2
- 230000003014 reinforcing effect Effects 0.000 claims 1
- 238000012545 processing Methods 0.000 abstract description 2
- 230000000052 comparative effect Effects 0.000 description 17
- 239000010935 stainless steel Substances 0.000 description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 229910001220 stainless steel Inorganic materials 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000006104 solid solution Substances 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 239000004567 concrete Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 150000001804 chlorine Chemical class 0.000 description 3
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 238000002161 passivation Methods 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 229910000599 Cr alloy Inorganic materials 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000004210 cathodic protection Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005536 corrosion prevention Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229920006334 epoxy coating Polymers 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 239000004574 high-performance concrete Substances 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000012085 test solution Substances 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- 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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- 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
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- 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
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/08—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires for concrete reinforcement
-
- 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
- C22C38/02—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
- 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
-
- 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
- C21D2211/009—Pearlite
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention belongs to the technical field of steel processing, and particularly relates to a high-strength steel bar with excellent corrosion resistance and earthquake resistance and a preparation method thereof. The steel bar comprises the following chemical components in percentage by weight: c:0.11 to 0.29 percent; si:0.11 to 0.19 percent; mn:1.40 to 1.60 percent; v:0.100 to 0.120 percent; nb:0.010 to 0.020%; als: 0.020-0.040%; n:0.020 to 0.025 percent; p is less than or equal to 0.025%; s is less than or equal to 0.025 percent; T.O is less than or equal to 0.004%; the balance of Fe and unavoidable impurity elements. The steel bar prepared by the method has excellent corrosion resistance and excellent earthquake resistance at 601-700 MPa, meets the requirements of domestic markets on the corrosion resistance and earthquake resistance high-strength steel bars under the condition of meeting the requirements of steel bar materials, and has simple production route, so that mass production can be realized in the existing steel factories.
Description
Technical Field
The invention belongs to the technical field of steel processing, and particularly relates to a high-strength steel bar with excellent corrosion resistance and earthquake resistance and a preparation method thereof.
Background
The reinforced bar is widely applied to various concrete building structures, although the alkaline concrete has a protective effect on the reinforced bar, the reinforced bar can be quickly corroded and destroyed along with the reduction of the alkalinity of the concrete, especially in environments where chlorine salts exist, such as natural chlorine salt environments of saline-alkali lands, salt lakes, coasts and the like, and artificial chlorine salt environments of bridges, roads and the like where ice salts are scattered, the service life of the building is seriously influenced, and huge losses are brought to national economy. In order to improve the corrosion resistance of the steel bars, a great deal of research is carried out at home and abroad, such as adopting high-performance concrete, concrete surface coating, steel bar rust inhibitor, epoxy coating steel bar, steel bar cathodic protection and other corrosion prevention technologies, although a certain effect is achieved, the defects of high cost and high construction requirement exist, the rust prevention effect of the steel bars is unstable, and the practical application effect is not good; in eighties of twenty-first century, stainless steel bars are developed in Europe and America, and the stainless steel bars have good corrosion resistance, but have high Cr and Ni alloy content, the total content of Cr and Ni is more than 20 percent, the production process is complex, the selling price is high, a large number of applications are limited, and the stainless steel bars are mainly used for key engineering projects with the design life of more than hundred years.
The Chinese patent publication No. CN107099734A discloses a corrosion-resistant steel bar for a marine building structure and a manufacturing method thereof, and the corrosion-resistant steel bar comprises the following components in percentage by weight: c:0.12 to 0.22 percent, si:0.25 to 0.70 percent, mn:0.50% -0.80%, P: less than or equal to 0.012 percent, S: less than or equal to 0.012%, cr:0.65 to 1.20 percent, V:0.06% -0.12%, N:0.013 to 0.017 percent, and the balance of Fe and unavoidable impurities. According to the invention, the alloy elements are added to refine the steel bar structure and improve the hardenability, meanwhile, the segregation, the porosity and the shrinkage cavity of a casting blank are reduced by adopting the modes of electromagnetic stirring, light reduction and the like in the smelting process, and the rolling and cooling process control is combined to produce the corrosion-resistant steel bar with good mechanical property and corrosion resistance, but the corrosion resistance is obviously insufficient, and the corrosion rate is 400-480 mu m/year and is basically equivalent to that of common carbon steel.
The Chinese patent publication No. CN109666852A discloses a production method of 500 MPa-grade ribbed stainless steel bars for marine building structures, the yield strength of the prepared stainless steel bars is above 500MPa, the PREN value ranges from 32 to 35, the chloride ion corrosion resistance is strong, and the yield ratio is more than or equal to 1.2. The stainless steel bar obtained by adopting 2205 billets and sequentially carrying out the processes of grinding, heating, rolling, on-line solid solution, acid washing and passivation and the like has excellent corrosion resistance and meets the requirements of steel for ocean engineering structures, but the production process is too complex, and production equipment such as on-line solid solution, acid washing and passivation and the like is not provided except for individual steel factories in China, so that large-area popularization and application cannot be realized. Therefore, there is a need for a high-strength reinforcing steel bar with excellent corrosion resistance and earthquake resistance and a preparation method thereof to solve the above problems.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides a high-strength steel bar with excellent corrosion resistance and earthquake resistance and a preparation method thereof. The uniform chemical components are adopted, and the steel bars with the strength level of more than 600MPa are obtained by utilizing the changes of heating, initial rolling and final rolling temperatures in the steel rolling process and an online quenching and tempering process after rolling, so that the requirements of different projects are met.
In order to achieve one of the above purposes, the present invention adopts the following technical scheme:
a high-strength steel bar with excellent corrosion resistance and earthquake resistance comprises the following chemical components in percentage by weight:
c:0.11 to 0.29 percent; si:0.11 to 0.19 percent; mn:1.40 to 1.60 percent; v:0.100 to 0.120 percent; nb:0.010 to 0.020%; als: 0.020-0.040%; n:0.020 to 0.025 percent; p is less than or equal to 0.025%; s is less than or equal to 0.025 percent; T.O is less than or equal to 0.004%; the balance of Fe and unavoidable impurity elements. Wherein t.o is the total oxygen content in the steel.
Preferably, the mass ratio of A=V/N in the steel bar is 4-6, so that the effect of V can be played to the greatest extent, and the waste of V is reduced.
Preferably, the steel bar consists of a surface and a core part, the surface is sequentially provided with a fine crystal layer and a protective layer from inside to outside, and the fine crystal layer and the core part are both ferrite and pearlite structures; the depth of the fine crystal layer is 10-15% of the radius of the steel bar, and the depth of the protective layerThe degree is 0.03-0.07mm, fe in the protective layer 3 O 4 The thickness of the protective layer is more than 70% of the depth of the protective layer.
Preferably, the depth of the fine grain layer is 11% of the radius of the steel bar, and the grain size of ferrite is more than or equal to 12.0 grade; the depth of the protective layer is 0.05mm, fe in the protective layer 3 O 4 The thickness of (2) is 80% of the depth of the protective layer.
Preferably, the yield strength of the steel bar is 601-700 MPa.
In order to achieve the second purpose, the invention provides a preparation method of high-strength steel bars with excellent corrosion resistance and earthquake resistance, which comprises the following steps:
s1, smelting a steelmaking raw material into crude molten steel, wherein the weight content of P and S in the crude molten steel at the smelting end point is less than or equal to 0.025%, the tapping temperature is 1660-1690 ℃, and deoxidation and alloying are carried out in a ladle in the tapping process;
s2, refining: the ladle enters a refining furnace, bottom blowing inert gas is started, electrodes are started for heating and heating, slag making materials are added for making white slag, sampling inspection and component fine adjustment are carried out after the heating time and the heating temperature are set, so that the steel ladle meets the component requirements of the steel bar, the ladle is discharged from a refining station, and the discharge temperature is 1550-1620 ℃;
s3, continuously casting a steel billet: the steel ladle is lifted to a continuous casting table to be cast into steel billets, in the casting process, the steel ladle, the middle ladle and the crystallizer are all cast in a whole-process protection way, the temperature of molten steel in the middle ladle is 1520-1560 ℃, the straightening temperature is 950-1000 ℃, and the straightening temperature is higher than the common straightening temperature, because Nb is inconsistent with the shrinkage coefficient (solidification) of the molten steel, and the ductility of Nb is poor, brittleness can easily occur, cracks can be generated, and the working pulling speed is 2.0-2.8 m/min;
s4, heating and rolling the steel billet: heating the steel billet in a heating furnace, preserving heat for 60-90 min, taking out the steel billet, and rolling the steel bar with the required specification after rough rolling, middle rolling and finish rolling in sequence, wherein the finish rolling temperature is 1070-1120 ℃;
s5, online quenching and tempering: and then quenching, tempering and cooling the steel bars in sequence, wherein the temperature of the upper cooling bed is 900-950 ℃, and the high-strength anti-seismic steel bars are prepared.
Preferably, in the step S1, the apparatus for smelting the steelmaking raw material into the crude molten steel is an arc furnace or a converter.
Preferably, in step S4, the heating temperature of the heating furnace is 1200 to 1250 ℃, which promotes dissolution of Nb, and this temperature makes V98% solid-dissolved in steel and Nb 85% solid-dissolved in steel. In the step S5, the second step of on-line tempering is on-line self-tempering, the steel bar is subjected to ultra-high temperature tempering by means of heat of the core part of the steel bar, and the temperature of reddening is 880-930 ℃.
Preferably, the first step of on-line quenching and tempering is carried out for 1 to 5 seconds.
Preferably, in step S5, the quenching time is 3 seconds, and if the quenching time is too short, the temperature of the surface of the steel bar cannot be reached, the quenching effect cannot be achieved, the quenching time is too long, the temperature of the surface of the steel bar is lowered, and the surface of the steel bar can form harmful martensite.
The invention has the advantages that:
(1) According to the actual demands of domestic markets on the corrosion-resistant and anti-seismic high-strength steel bars, the invention designs the component range and the preparation method of the steel for the high-strength steel bars with excellent corrosion resistance and anti-seismic performance, which are higher than 600MPa, by combining the existing technological equipment conditions of most steel mills, and the steel bar material with the performance meeting the requirements is produced.
(2) The invention mainly adopts a V, nb combined microalloying mode, utilizes the dispersion precipitation of V (C, N), especially VN compounds in steel, plays roles of precipitation strengthening and fine grain strengthening, utilizes Nb to obviously delay austenite recrystallization and refine grains, greatly improves the strength on the premise of ensuring the corrosion resistance and the earthquake resistance of the reinforcing steel bars, and has the advantages of no less than 12 grades of ferrite grain size. Wherein V in the components is added by VN (16) alloy, and a Si, mn and Al composite deoxidization method is adopted, and T.O is controlled, so that the corrosion resistance and the earthquake resistance of the steel are obviously improved. Meanwhile, the content of N is limited to be within the range of 0.020-0.040%, metal element particles (MN particles) are formed by using low-cost N and are separated out at a grain boundary, so that the strength of steel is greatly improved, the range of the yield strength of the steel is limited, and the requirement of the steel on the high yield ratio is met. In order to exert the function of V to the maximum extent and reduce the waste of V, a=v/N is required to be 4 to 6. To further giveThe corrosion resistance is improved, and the uniform and compact Fe is formed on the surface of the steel bar through the temperature optimization of on-line quenching and tempering 3 O 4 A mainly protective layer.
(3) The production process route of the invention is converter (or arc furnace), LF refining and continuous casting of 150-170 mm 2 Square billet, heating by a heating furnace, rolling by a wire rod rolling mill, on-line quenching and tempering, and air cooling by a cooling bed, high-strength steel bars with excellent comprehensive performance and more than 600MPa level can be produced, and the mechanical properties can meet the following requirements: the yield strength ReL is 601-700 MPa, the tensile strength Rm is 750-1875 MPa, the elongation after break A is more than or equal to 15%, the total elongation Agt is more than or equal to 9.0% under the maximum force, the strength-to-deflection ratio is more than or equal to 1.25, the relative corrosion rate with the common HRB400 steel bar is less than or equal to 50%, the corrosion resistance is improved by 1 time, and the production process is simple and feasible.
(4) The invention adds Al into molten steel to partially form Al 2 O 3 Partially dissolved in solid iron, with the solid-solution Al forming diffuse AlN or continuing to form solid solution in the iron with different heating and cooling conditions, the solid-solution Al (including subsequently precipitated AlN) being readily soluble in acid when examined, known as acid-soluble aluminum (Als); in the invention, acid-soluble aluminum is combined with N to form AlN second-phase particles, and the pinning effect is played on migration movement of austenite grain boundaries, so that grains are refined. If the content of acid-soluble aluminum in the steel is low, the number of AlN second phase particles formed is insufficient, the pinning force is weak, and the growth of crystal grains cannot be effectively prevented; when the acid-soluble aluminum content is high, the distance of Al atoms diffusing is small with the increase of temperature, and the grains are aggregated and are coarse instead.
Drawings
Fig. 1 is a surface microstructure of a sample of the rebar produced in example 1 of the present invention at 500 x magnification, wherein: the black structure is pearlite, the white structure is ferrite, and the ferrite grain size is 12.0 grade.
Detailed Description
The present invention will be further described in detail with reference to the drawings and examples, wherein all other examples, which are obtained by a person skilled in the art without making any inventive effort, are included in the scope of the present invention.
A high-strength steel bar with excellent corrosion resistance and earthquake resistance comprises the following chemical components in percentage by weight:
c:0.11 to 0.29 percent; si:0.11 to 0.19 percent; mn:1.40 to 1.60 percent; v:0.100 to 0.120 percent; nb:0.010 to 0.020%; als: 0.020-0.040%; n:0.020 to 0.025 percent; p is less than or equal to 0.025%; s is less than or equal to 0.025 percent; T.O is less than or equal to 0.004%; the balance of Fe and unavoidable impurity elements. V/n=4-6 in the rebar.
The steel bar consists of a surface and a core part, the surface is sequentially provided with a fine grain layer and a protective layer from inside to outside, the fine grain layer and the core part are both ferrite and pearlite structures, the depth of the fine grain layer is 10-15 percent, preferably 11 percent, of the radius of the steel bar, and the depth of the protective layer is 0.03-0.07mm, preferably 0.05mm; fe in the protective layer 3 O 4 The thickness of (2) is 70% -90%, preferably 80% of the depth of the protective layer. The grain size of ferrite is more than or equal to 12.0 grade.
A preparation method of high-strength steel bar with excellent corrosion resistance and earthquake resistance comprises the following steps:
s1, smelting a steelmaking raw material into crude molten steel, wherein the weight content of P and S in the crude molten steel at the smelting end point is less than or equal to 0.025%, the tapping temperature is 1660-1690 ℃, and deoxidation and alloying are carried out in a ladle in the tapping process;
s2, refining: the ladle enters a refining furnace, bottom blowing inert gas is started, electrodes are started for heating and heating, slag making materials are added for making white slag, sampling inspection and component fine adjustment are carried out after the heating time and the heating temperature are set, so that the steel ladle meets the component requirements of the steel bar, the ladle is discharged from a refining station, and the discharge temperature is 1550-1620 ℃;
s3, continuously casting a steel billet: the steel ladle is lifted to a continuous casting table to be cast into steel billets, and in the casting process, the steel ladle, the middle ladle and the crystallizer are all cast in a whole-course protection way, the temperature of molten steel in the middle ladle is 1520-1560 ℃, the straightening temperature is 950-1000 ℃, and the working pulling speed is 2.0-2.8 m/min;
s4, heating and rolling the steel billet: heating the steel billet in a heating furnace to 1200-1250 ℃, preserving heat for 60-90 min, taking out the steel billet, and rolling the steel bar with the required specification after rough rolling, middle rolling and finish rolling in sequence, wherein the finish rolling temperature is 1070-1120 ℃;
s5, online quenching and tempering: and then quenching, tempering and cooling the steel bars in sequence, wherein the temperature of the upper cooling bed is 900-950 ℃, and the high-strength anti-seismic steel bars are prepared.
Wherein, in the step S1, the equipment for smelting the steelmaking raw materials into crude molten steel is an electric arc furnace or a converter; the first step of on-line quenching and tempering is that the quenching time is 1-5 seconds.
The smelting chemical compositions of the invention in the examples 1, 2 and 3 and the comparative examples 1, 2 and 3 are shown in Table 1, the preparation process parameters are shown in Table 2, the mechanical properties results are shown in Table 3, and the remaining preparation steps of example 1, example 2, example 3 and comparative examples 1, comparative examples 2, comparative example 3 are identical to the previous preparation steps.
Wherein P of comparative example 1 exceeds the standard, a value (i.e., V/N) of comparative example 2 exceeds the standard, and the preparation process parameters of comparative example 1 and comparative example 2 satisfy the requirements, and the preparation process parameters of comparative example 3 do not satisfy the requirements.
TABLE 1 smelting chemistry (%)
| Case (B) | C | Si | Mn | P | S | V | Nb | Als | N | T.O | A |
| Example 1 | 0.15 | 0.15 | 1.50 | 0.025 | 0.025 | 0.110 | 0.015 | 0.03 | 0.023 | 0.003 | 4.8 |
| Example 2 | 0.11 | 0.19 | 1.40 | 0.022 | 0.020 | 0.120 | 0.020 | 0.02 | 0.020 | 0.004 | 6 |
| Example 3 | 0.19 | 0.11 | 1.60 | 0.021 | 0.022 | 0.100 | 0.010 | 0.04 | 0.025 | 0.002 | 4 |
| Comparative example 1 | 0.15 | 0.15 | 1.50 | 0.028 | 0.025 | 0.110 | 0.015 | 0.03 | 0.030 | 0.003 | 4.8 |
| Comparative example 2 | 0.11 | 0.19 | 1.40 | 0.022 | 0.020 | 0.120 | 0.020 | 0.02 | 0.040 | 0.004 | 3 |
| Comparative example 3 | 0.18 | 0.14 | 1.56 | 0.022 | 0.021 | 0.110 | 0.012 | 0.01 | 0.022 | 0.005 | 5 |
TABLE 2 preparation process parameters for examples 1-3 and comparative examples 1-3
TABLE 3 mechanical Properties of examples 1-3 and comparative examples 1-3
Wherein: r is R eL Yield strength (more than 600 grades are required); r is R m Is tensile strength; a is the elongation after break; a is that gt Elongation at maximum force; dorsiflexion ratio = measured tensile strength/measured yield strength.
The invention adopts a dip corrosion test to evaluate the corrosion resistance.
The test solution for the dip corrosion test is 3.5% NaCl solution, the solution temperature is 35+/-2 ℃, the drying temperature is 45+/-2 ℃, and the humidity is 30+/-2 ℃. Each cycle period was 60.+ -. 5min, with a soak of 12.+ -. 2 ℃ and an exposure of 48.+ -. 2 ℃. The test period is 7 days; the corrosion rates were averaged for 6 replicates per test.
Relative corrosion rate = corrosion rate of example or comparative example/HRB 400 x 100%.
As is clear from Table 3, the mechanical properties of examples 1 to 3 satisfy the requirements of the invention, while the corrosion resistance of comparative examples 1 and 3 does not reach the standard, the corrosion resistance of the steel bar cannot be satisfied, and R of comparative example 2 eL The yield strength is lower than 600MPa, and is lower than R of the examples 1-3 eL Yield strength.
The microscopic structure diagram of the steel bar sample prepared in the example 1 is detected, as shown in fig. 1, and the microscopic structure diagram of the sample is amplified by 500 times, and it can be seen that the steel bar has a ferrite+pearlite structure, meets the requirements of GB/T1499.2, and can be normally used, such as welding. The ferrite grain size of the steel bar is more than or equal to 12 grades, the finer the grains are, the more grain boundaries are, the larger the resistance to crack generation and expansion is, the less fracture is easy, and the steel bar further has high strength and toughness.
The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.
Claims (10)
1. The high-strength steel bar with excellent corrosion resistance and earthquake resistance is characterized by comprising the following chemical components in percentage by weight:
c:0.11 to 0.29 percent; si:0.11 to 0.19 percent; mn:1.40 to 1.60 percent; v:0.100 to 0.120 percent; nb:0.010 to 0.020%; als: 0.020-0.040%; n:0.020 to 0.025 percent; p is less than or equal to 0.025%; s is less than or equal to 0.025 percent; T.O is less than or equal to 0.004%; the balance of Fe and unavoidable impurity elements.
2. The high-strength steel bar with excellent corrosion resistance and earthquake resistance according to claim 1, wherein: v/n=4-6 in the steel bar.
3. A device according to claim 1 havingThe high-strength steel bar with excellent corrosion resistance and earthquake resistance is characterized in that: the steel bar consists of a surface and a core part, wherein the surface is sequentially provided with a fine crystal layer and a protective layer from inside to outside, and the fine crystal layer and the core part are both ferrite and pearlite structures; the depth of the fine crystal layer is 10-15% of the radius of the steel bar, the depth of the protective layer is 0.03-0.07mm, and Fe in the protective layer 3 O 4 The thickness of the protective layer is more than 70% of the depth of the protective layer.
4. A high-strength reinforcing bar having excellent corrosion resistance and earthquake resistance as set forth in claim 3, wherein: the depth of the fine grain layer is 11% of the radius of the steel bar, and the grain size of the ferrite is more than or equal to 12.0 grade; the depth of the protective layer is 0.05mm, fe in the protective layer 3 O 4 The thickness of (2) is 80% of the depth of the protective layer.
5. The high-strength steel bar with excellent corrosion resistance and earthquake resistance according to claim 1, wherein: the yield strength of the steel bar is 601-700 MPa.
6. A method for producing a high-strength steel bar having excellent corrosion resistance and earthquake resistance as claimed in any one of claims 1 to 5, comprising the steps of:
s1, smelting a steelmaking raw material into crude molten steel, wherein the weight content of P and S in the crude molten steel at the smelting end point is less than or equal to 0.025%, the tapping temperature is 1660-1690 ℃, and deoxidization and alloying are carried out in a ladle in the tapping process;
s2, refining: the ladle enters a refining furnace, bottom blowing inert gas is started, electrodes are started for heating and heating, slag making materials are added for making white slag, sampling inspection and component fine adjustment are carried out after the heating time and the heating temperature are set, so that the steel ladle meets the component requirements of the steel bar, the ladle is discharged from a refining station, and the discharge temperature is 1550-1620 ℃;
s3, continuously casting a steel billet: the steel ladle is lifted to a continuous casting table to be cast into steel billets, and in the casting process, the steel ladle, the middle ladle and the crystallizer are all cast in a whole-course protection way, the temperature of molten steel in the middle ladle is 1520-1560 ℃, the straightening temperature is 950-1000 ℃, and the working pulling speed is 2.0-2.8 m/min;
s4, heating and rolling the steel billet: heating the steel billet in a heating furnace, preserving heat for 60-90 min, taking out the steel billet, and rolling the steel bar with the required specification after rough rolling, middle rolling and finish rolling in sequence, wherein the finish rolling temperature is 1070-1120 ℃;
s5, online quenching and tempering: quenching, tempering and cooling the steel bars in sequence, wherein the temperature of the upper cooling bed is 900-950 ℃, and the steel bars are prepared.
7. The high-strength steel bar with excellent corrosion resistance and earthquake resistance and the preparation method thereof are characterized in that: the equipment for smelting the steelmaking raw materials into crude molten steel in the step S1 is an electric arc furnace or a converter.
8. The high-strength steel bar with excellent corrosion resistance and earthquake resistance and the preparation method thereof are characterized in that: in the step S4, the heating temperature of the heating furnace is 1200-1250 ℃; in the step S5, the tempering temperature of the tempered steel is 880-930 ℃.
9. The high-strength steel bar with excellent corrosion resistance and earthquake resistance and the preparation method thereof are characterized in that: in step S5, the quenching time is 1 to 5 seconds.
10. The high-strength steel bar with excellent corrosion resistance and earthquake resistance and the preparation method thereof are characterized in that: in step S5, the quenching time was 3 seconds.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310646597.6A CN116657058B (en) | 2023-06-02 | 2023-06-02 | High-strength steel bar with excellent corrosion resistance and earthquake resistance and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310646597.6A CN116657058B (en) | 2023-06-02 | 2023-06-02 | High-strength steel bar with excellent corrosion resistance and earthquake resistance and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116657058A true CN116657058A (en) | 2023-08-29 |
| CN116657058B CN116657058B (en) | 2024-03-26 |
Family
ID=87713312
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310646597.6A Active CN116657058B (en) | 2023-06-02 | 2023-06-02 | High-strength steel bar with excellent corrosion resistance and earthquake resistance and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116657058B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0949020A (en) * | 1995-08-09 | 1997-02-18 | Sumitomo Metal Ind Ltd | Production of steel material for low temperature reinforcement |
| JPH09111340A (en) * | 1995-08-11 | 1997-04-28 | Sumitomo Metal Ind Ltd | High strength and low yield ratio steel for reinforcing bar and its production |
| CN111945074A (en) * | 2020-08-28 | 2020-11-17 | 安徽吾兴新材料有限公司 | 635 MPa-grade high-strength anti-seismic reinforcing steel bar and preparation method thereof |
| CN112226693A (en) * | 2020-10-10 | 2021-01-15 | 桂林理工大学 | Low-alloy high-strength corrosion-resistant steel bar and preparation method thereof |
| CN115198197A (en) * | 2022-08-22 | 2022-10-18 | 安徽吾兴新材料有限公司 | 640 MPa-grade high-strength anti-seismic reinforcing steel bar and preparation method thereof |
-
2023
- 2023-06-02 CN CN202310646597.6A patent/CN116657058B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0949020A (en) * | 1995-08-09 | 1997-02-18 | Sumitomo Metal Ind Ltd | Production of steel material for low temperature reinforcement |
| JPH09111340A (en) * | 1995-08-11 | 1997-04-28 | Sumitomo Metal Ind Ltd | High strength and low yield ratio steel for reinforcing bar and its production |
| CN111945074A (en) * | 2020-08-28 | 2020-11-17 | 安徽吾兴新材料有限公司 | 635 MPa-grade high-strength anti-seismic reinforcing steel bar and preparation method thereof |
| CN112226693A (en) * | 2020-10-10 | 2021-01-15 | 桂林理工大学 | Low-alloy high-strength corrosion-resistant steel bar and preparation method thereof |
| CN115198197A (en) * | 2022-08-22 | 2022-10-18 | 安徽吾兴新材料有限公司 | 640 MPa-grade high-strength anti-seismic reinforcing steel bar and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116657058B (en) | 2024-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111041356B (en) | Niobium-containing atmospheric corrosion-resistant 14.9-grade high-strength bolt steel and production method thereof | |
| WO2022022040A1 (en) | Low temperature-resistant hot-rolled h-type steel for 355mpa marine engineering and preparation method therefor | |
| CN110938732A (en) | Titanium-containing atmospheric corrosion-resistant 14.9-grade high-strength bolt steel and production method thereof | |
| CN112391569B (en) | Preparation method of 600MPa ultrahigh-strength anti-seismic steel bar | |
| CN114015848A (en) | Needle-shaped ferrite type high-strength steel bar and preparation method thereof | |
| CN114672605B (en) | Corrosion-resistant steel bar mechanical connection sleeve, wire rod and production method of wire rod | |
| CN114196884A (en) | 400 MPa-grade microalloyed corrosion-resistant reinforcing steel bar and production method thereof | |
| CN107557690A (en) | The super-thick steel plate and its manufacture method of a kind of low temperature resistant and anti-lamellar tearing | |
| CN110106445B (en) | High-strength high-low-temperature-toughness steel for ocean platform casting node and preparation method thereof | |
| CN111411304A (en) | Q460-grade hot-rolled angle steel and preparation method thereof | |
| CN109881121B (en) | Chloride ion corrosion-resistant high-strength anti-seismic reinforcing steel bar and production method and application thereof | |
| CN108914005B (en) | Super-thick corrosion-resistant steel plate with yield strength larger than 460MPa and excellent low-temperature toughness and production method thereof | |
| CN101775552A (en) | High-strength high-flexibility low-yield-ratio fire resistant steel and production method thereof | |
| CN106676418B (en) | The atmosphere corrosion resistance structural steel molten steel of nitrogen containing niobium and atmosphere corrosion resistance structural steel and its production method | |
| CN114875331B (en) | 610 MPa-grade thick steel plate with excellent core fatigue performance and production method thereof | |
| CN116657058B (en) | High-strength steel bar with excellent corrosion resistance and earthquake resistance and preparation method thereof | |
| CN115572905A (en) | 690 MPa-grade tempering-resistant low-temperature quenched and tempered steel and manufacturing method thereof | |
| CN107587048B (en) | One kind atmosphere corrosion resistance structural steel molten steel of nitrogen containing vanadium and atmosphere corrosion resistance structural steel and its production method | |
| CN107587057B (en) | A kind of atmosphere corrosion resistance structural steel molten steel and the atmosphere corrosion resistance structural steel of titanium containing chromium and its production method | |
| CN106676428B (en) | Atmosphere corrosion resistance structural steel molten steel and the atmosphere corrosion resistance structural steel of nitrogen containing niobium and its production method | |
| CN106676417B (en) | The atmosphere corrosion resistance structural steel molten steel of nitrogen containing vanadium and atmosphere corrosion resistance structural steel and its production method | |
| CN106676402B (en) | The atmosphere corrosion resistance structural steel molten steel of titanium containing chromium and atmosphere corrosion resistance structural steel and its production method | |
| CN106676398B (en) | The nitrogen atmosphere corrosion resistance structural steel molten steel of titanium containing vanadium and atmosphere corrosion resistance structural steel and its production method | |
| CN117344232A (en) | 490 MPa-level thick steel plate with high core fatigue strength and manufacturing method thereof | |
| CN107587063B (en) | One kind nitrogen atmosphere corrosion resistance structural steel molten steel of titanium containing vanadium and atmosphere corrosion resistance structural steel and its production method |
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 |