CN116179960B - Thin GI high-strength steel strip with 700 MPa-grade yield strength and production method thereof - Google Patents
Thin GI high-strength steel strip with 700 MPa-grade yield strength and production method thereof Download PDFInfo
- Publication number
- CN116179960B CN116179960B CN202310162242.XA CN202310162242A CN116179960B CN 116179960 B CN116179960 B CN 116179960B CN 202310162242 A CN202310162242 A CN 202310162242A CN 116179960 B CN116179960 B CN 116179960B
- Authority
- CN
- China
- Prior art keywords
- percent
- strength
- rolling
- steel strip
- temperature
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 72
- 239000010959 steel Substances 0.000 title claims abstract description 72
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 27
- 238000000137 annealing Methods 0.000 claims abstract description 31
- 238000005098 hot rolling Methods 0.000 claims abstract description 15
- 239000000126 substance Substances 0.000 claims abstract description 12
- 238000002791 soaking Methods 0.000 claims abstract description 10
- 238000005246 galvanizing Methods 0.000 claims abstract description 9
- 239000012535 impurity Substances 0.000 claims abstract description 9
- 238000005096 rolling process Methods 0.000 claims description 28
- 238000001816 cooling Methods 0.000 claims description 18
- 238000005097 cold rolling Methods 0.000 claims description 14
- 238000009749 continuous casting Methods 0.000 claims description 11
- 238000001953 recrystallisation Methods 0.000 claims description 9
- 239000010960 cold rolled steel Substances 0.000 claims description 7
- 229910001566 austenite Inorganic materials 0.000 claims description 6
- 238000005554 pickling Methods 0.000 claims description 5
- 229910000859 α-Fe Inorganic materials 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 4
- 229910001562 pearlite Inorganic materials 0.000 claims description 4
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 3
- 238000005266 casting Methods 0.000 claims description 3
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 239000011701 zinc Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 22
- 230000002787 reinforcement Effects 0.000 abstract description 2
- 238000005728 strengthening Methods 0.000 description 12
- 229910001335 Galvanized steel Inorganic materials 0.000 description 9
- 239000008397 galvanized steel Substances 0.000 description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 9
- 229910045601 alloy Inorganic materials 0.000 description 7
- 239000000956 alloy Substances 0.000 description 7
- 239000006104 solid solution Substances 0.000 description 6
- 230000009286 beneficial effect Effects 0.000 description 5
- 238000010276 construction Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 229910052748 manganese Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910052698 phosphorus Inorganic materials 0.000 description 3
- 239000013078 crystal Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- 229910052758 niobium Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 229910052729 chemical element 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
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 238000009740 moulding (composite fabrication) Methods 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 229910052720 vanadium Inorganic materials 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
- C21D1/26—Methods of annealing
-
- 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
- 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
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
- C23C2/36—Elongated material
- C23C2/40—Plates; Strips
-
- 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
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)
- Chemical Kinetics & Catalysis (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
The invention discloses a thin-specification high-strength GI steel strip with 700 MPa-grade yield strength and a production method thereof, and mainly solves the technical problem that the existing high-strength GI steel strip with 700 MPa-grade yield strength is high in manufacturing cost. The hot dip galvanized high-strength steel strip provided by the invention comprises the following chemical components in percentage by weight: c:0.16 to 0.18 percent, si:0.15 to 0.22 percent, mn:1.0 to 1.2 percent, P:0.015 to 0.025 percent, S is less than or equal to 0.03 percent, als:0.03 to 0.05 percent, nb:0.015 to 0.025 percent, and the balance of Fe and unavoidable impurities. The invention adopts a low-cost chemical component system and a low hot rolling coiling temperature and hot galvanizing annealing soaking temperature process to realize high-strength mechanical property. The yield strength of the steel belt is more than or equal to 700MPa, the tensile strength is more than or equal to 720MPa, the elongation after fracture A 50 is more than or equal to 6%, and the steel belt is mainly used in the manufacturing field of structural reinforcements such as traffic buildings.
Description
Technical Field
The invention belongs to the technical field of metallurgy, and particularly relates to a thin-specification GI high-strength steel strip with yield strength of 700MPa and a production method thereof.
Background
With the rapid development of national economy, the low-cost thin-specification high-strength hot dip galvanized steel strip is more and more widely applied, and the hot dip galvanized steel strip is greatly popularized in the field of traffic construction by virtue of good corrosion resistance and deformation resistance, so that the hot dip galvanized steel strip has great significance for energy conservation and environmental protection.
In general, the production route of hot dip galvanized high strength steel mainly comprises: firstly, by adding alloy elements for strengthening, the method can obtain high-strength and high-toughness steel, but the alloy cost is high, the galvanized surface quality is easily deteriorated, and the plating adhesion is affected; secondly, the strength of the steel plate is improved by improving the rapid cooling rate and utilizing phase change reinforcement, and the method has high requirements on the rapid cooling technology and high investment cost of production equipment; thirdly, the cold rolling work hardening is fully utilized, the incomplete annealing process is carried out, the steel strip is not completely recrystallized, most fiber tissues are reserved, high strength can be obtained, but the elongation after fracture is relatively low, and the method is suitable for products with low requirements on the plasticity of materials. For the steel for the traffic construction, the steel is usually formed by adopting processing modes such as rolling and the like, and has higher requirements on strength and lower requirements on plasticity of materials, so that the incomplete annealing process is adopted, the production cost is low, and the adhesion of the steel strip surface coating is good.
The patent number CN102199723A discloses a high-strength cold-rolled hot-dip galvanized precipitation-strengthened steel plate and a manufacturing method thereof, wherein the chemical composition of a substrate is ：C：0.09～0.12wt％,Si≤0.05wt％,Mn：0.8～1.8wt％,P≤0.02wt％,S≤0.01wt％,N≤0.008wt％,Als：0.02～0.06wt％,Nb+Ti：0.05～0.08wt％,, and the balance of Fe and unavoidable impurities. The microstructure is ferrite plus second phase particles, the diameter of the second phase particles is less than 6 mu m, the yield strength is 500-600 MPa, the tensile strength is 570-710 MPa, and the total elongation is more than 14% (80 gauge length, transverse stretching). The process adds more alloy, has higher cost, and the quality control of the slab with the C content being designed in the peritectic area is unstable. In addition, the recrystallization annealing temperature of the continuous annealing is 750-800 ℃, and the main strengthening modes are precipitation strengthening and fine crystal strengthening.
The patent number CN106148823A discloses a 550Mpa high-strength structural-grade galvanized steel strip, which comprises the following chemical components in percentage by mass: c:0.04 to 0.06 percent, mn:0.15 to 0.30 percent, si is less than or equal to 0.03 percent, S is less than or equal to 0.015 percent, P is less than or equal to 0.022 percent, als: 0.025-0.06%, N is less than or equal to 0.0050%, and the balance is iron and unavoidable impurities. The production method comprises the working procedures of converter smelting, LF furnace refining, continuous casting, hot rolling, coiling, pickling cold continuous rolling and galvanization; the component design of solid solution strengthening of Si and Mn is adopted, noble alloys such as Nb, ti, V and the like are not added, and the cost is effectively reduced; the subsequent hot rolling, cold rolling and hardening control process and low temperature annealing and galvanizing process are adopted, so that the excellent performance of the final product is ensured, the process is simple, and the production cost is low. However, C, mn has lower components, weak solid solution strengthening effect, can not reach 700 Mpa-level strength, and the annealing soaking temperature is too low, which is not beneficial to plate type quality and is not easy to control in industrial production.
Patent number CN 103882202B discloses a manufacturing method of continuous annealing high-strength hot galvanized steel, which comprises the following chemical components in percentage by mass: c: 0.02-0.04%, si:0.001 to 0.03 percent, mn:0.10 to 0.40 percent, P: 0.001-0.015%, S:0.001 to 0.010 percent, B:0.0010 to 0.0020 percent, and the balance of Fe and unavoidable impurity elements. The component system adopts low carbon and B, has weak solid solution strengthening effect, can not reach 700 Mpa-level strength, adopts low-temperature annealing soaking temperature of 500-550 ℃, can not read by a conventional furnace zone high Wen Banwen meter, and is not beneficial to plate type quality due to too low annealing soaking temperature, and is not easy to control in industrial production.
The patent number CN 101348880A discloses a production method of a high-strength galvanized plate for a structure, wherein the steel plate comprises the following chemical components in percentage by mass: c:0.16 to 0.20 percent, mn:0.9 to 1.1 percent, si is less than or equal to 0.05 percent, P is less than or equal to 0.020 percent, S is less than or equal to 0.020 percent, als is 0.02 to 0.06 percent, and the balance is Fe, wherein the galvanization annealing temperature is 680 to 720 ℃. The yield strength of the product can only be about 400MPa, and the 700MPa strength can not be achieved according to the component process.
The patent number CN111020437A discloses a manufacturing method of hot dip galvanized steel strip with yield strength more than 580Mpa level, comprising the following steps: selecting chemical components and mass percent of manufactured steel strips: c:0.16 to 0.20 percent, si is less than or equal to 0.05 percent, mn:1.1 to 1.3 percent, P is less than or equal to 0.02 percent, S is less than or equal to 0.02 percent, als:0.025 to 0.06 percent, and the balance of Fe and unavoidable impurities; the manufacturing method of the hot dip galvanized steel strip with yield strength of more than 580Mpa level is simple in component design, does not add precious alloy elements, adopts a 600-630 ℃ semi-annealing process, is low in energy consumption and production cost, can achieve high yield strength and certain processability, and meets the requirements of industries such as buildings. According to the component process, only about 600MPa of yield strength can be realized, and 700MPa strength cannot be achieved.
Disclosure of Invention
The invention aims to provide a GI high-strength steel strip with a thin specification and 700MPa grade yield strength and a production method thereof.
The technical scheme adopted for solving the technical problems is as follows: a thin GI high-strength steel belt with 700MPa grade yield strength comprises the following chemical components in percentage by mass: c:0.16 to 0.18 percent, si:0.15 to 0.22 percent, mn:1.0 to 1.2 percent, P:0.015 to 0.025 percent, S is less than or equal to 0.03 percent, als:0.03 to 0.05 percent, nb:0.015 to 0.025 percent, and the balance of Fe and unavoidable impurities.
Specifically, the microstructure of the steel belt is ferrite and pearlite, the yield strength R P0.2 is more than or equal to 700MPa, the tensile strength R m is more than or equal to 720MPa, and the elongation after fracture A 50 is more than or equal to 6%.
The production method of the GI high-strength steel belt with the thin specification yield strength of 700MPa is characterized by comprising the following steps:
1) Continuously casting molten steel to obtain a continuous casting plate blank;
2) Heating the continuous casting slab to 1220-1250 ℃, and then carrying out hot rolling, wherein the hot rolling is a two-stage rolling process, rolling is carried out above the austenite recrystallization temperature, and the rough rolling finishing temperature is 1060-1080 ℃; rolling in an austenite non-recrystallization temperature zone, wherein the finish rolling temperature is 860-880 ℃, laminar cooling is performed by adopting front-stage cooling after finish rolling, the coiling temperature is 550-570 ℃, a U-shaped coiling mode is adopted, the coiling temperature of the head and the tail of the steel strip is higher than the coiling temperature of the middle part by 30 ℃, and a hot rolled steel coil with the thickness of 2.0-3.0 mm is obtained by coiling;
3) Cooling the hot rolled steel coil, re-uncoiling, and carrying out pickling, cold rolling and coiling to obtain a cold rolled steel strip with the thickness of 0.5-0.9 mm, wherein the cold rolling reduction rate is 70-76%;
4) Cooling the cold-rolled steel coil, re-uncoiling, annealing by a vertical continuous annealing furnace, hot galvanizing, finishing and coiling to obtain a finished GI steel belt with the thickness of 0.5-0.9 mm, wherein the temperature of an annealing soaking section is 600-610 ℃, the annealing time of the steel belt in the soaking section is 85-100 s, the temperature of the steel belt entering a zinc pot is 470-490 ℃, and the finishing elongation is 0.3-0.5%.
The invention has the following beneficial effects: according to the invention, by adopting the control process of C, si, mn, P solid solution strengthening effect and hot rolling fine grain strengthening, adding proper Nb element, under the conditions of not remarkably improving alloy cost, not having continuous annealing hot galvanizing production line equipment below 600 ℃ and the like, adopting high cold rolling reduction rate to cold-roll to a thin specification cold-rolled steel strip with the thickness of 0.5-0.9 mm, tightly combining with a furnace roller in the low-temperature annealing process, reducing the deviation risk of a furnace region, producing GI high-strength steel strip with the yield strength of 700MPa with low cost, improving the production efficiency, and being suitable for industrial mass production.
Detailed Description
The present invention will now be described in further detail.
A GI high-strength steel strip with a thin specification and 700MPa yield strength and a production method thereof mainly solve the technical problem that the existing GI high-strength steel strip with the 700MPa yield strength is high in manufacturing cost and can meet the requirements of high strength and low elongation of traffic construction steel.
A production method of a thin GI high-strength steel belt with 700MPa grade yield strength comprises the following steps:
1) Continuously casting molten steel to obtain a continuous casting plate blank, wherein the molten steel comprises the following chemical components in percentage by weight: c:0.16 to 0.18 percent, si:0.15 to 0.22 percent, mn:1.0 to 1.2 percent, P:0.015 to 0.025 percent, S is less than or equal to 0.03 percent, als:0.03 to 0.05 percent, nb:0.015 to 0.025 percent, and the balance of Fe and unavoidable impurities;
2) Heating the continuous casting slab to 1220-1250 ℃, and then carrying out hot rolling, wherein the hot rolling is a two-stage rolling process, rolling is carried out above the austenite recrystallization temperature, and the rough rolling finishing temperature is 1060-1080 ℃; rolling in an austenite non-recrystallization temperature zone, wherein the finish rolling temperature is 860-880 ℃, laminar cooling is performed by adopting front-stage cooling after finish rolling, the coiling temperature is 550-570 ℃, a U-shaped coiling mode is adopted, the coiling temperature of the head and the tail of the steel strip is higher than the coiling temperature of the middle part by 30 ℃, and a hot rolled steel coil with the thickness of 2.0-3.0 mm is obtained by coiling;
3) Cooling the hot rolled steel coil, re-uncoiling, and carrying out pickling, cold rolling and coiling to obtain a cold rolled steel strip with the thickness of 0.5-0.9 mm, wherein the cold rolling reduction rate is 70-76%;
4) Cooling the cold-rolled steel coil, re-uncoiling, annealing by a vertical continuous annealing furnace, hot galvanizing, finishing and coiling to obtain a finished GI steel belt with the thickness of 0.5-0.9 mm, wherein the temperature of an annealing soaking section is 600-610 ℃, the annealing time of the steel belt in the soaking section is 85-100 s, the temperature of the steel belt entering a zinc pot is 470-490 ℃, and the finishing elongation is 0.3-0.5%.
The invention adopts a low-cost alloy cost system, has extremely strong solid solution strengthening effect on the premise of not deteriorating the performance by solid solution strengthening of C, si and Mn and adding a small amount of P element, has better fine crystal strengthening effect by adding a small amount of Nb element, can improve the annealing recrystallization temperature of the steel strip, is beneficial to inhibiting the recrystallization of the steel strip when the steel strip is annealed at the temperature of more than 600 ℃ under the condition of limited plate temperature measurement process of a production line, and ensures the structure and performance of a finished product and the surface and plate type quality.
The adoption of lower hot rolling coiling temperature is beneficial to obtaining fine ferrite and pearlite structures, improves the strength of the steel strip, and particularly has a incomplete annealing process, and the hot rolling structure has strong hereditary property on cold-rolled finished products; the U-shaped coiling mode is adopted, so that the uneven degree of head and tail cooling of the steel coil is reduced, and the performance stability of the through plate is improved.
The steel strip can obtain higher cold rolling hardening strength by adopting higher cold rolling reduction rate; the low-temperature annealing galvanization process is adopted to enable the steel strip to recover but not completely recrystallize, and a part of rolled hard structure is reserved, so that higher strength and proper elongation after break can be obtained.
The microstructure of the GI high-strength steel strip with the yield strength of 700MPa is ferrite and pearlite, the yield strength R P0.2 is more than or equal to 700MPa, the tensile strength R m is more than or equal to 720MPa, the elongation after fracture A 50 is more than or equal to 6%, and the use requirements of rolling, processing, forming and the like of the steel for the traffic construction can be completely met.
Examples 1-3:
Table 1 shows the chemical composition (in weight percent) of the steels of the examples of the invention, the balance being Fe and other unavoidable impurities.
Table 1 chemical composition of the steel according to the example of the invention, unit: weight percent (%)
| Chemical element | C | Si | Mn | P | S | Als | Nb |
| The invention is that | 0.16～0.18 | 0.15～0.22 | 1.0～1.2 | 0.015～0.025 | ≤0.03 | 0.03～0.05 | 0.015～0.025 |
| Example 1 | 0.17 | 0.21 | 1.1 | 0.016 | 0.01 | 0.03 | 0.017 |
| Example 2 | 0.18 | 0.15 | 1.0 | 0.022 | 0.01 | 0.04 | 0.022 |
| Example 3 | 0.16 | 0.20 | 1.2 | 0.023 | 0.02 | 0.05 | 0.024 |
According to the requirements of material composition design, molten steel with qualified converter top and bottom composite converting composition is adopted, and a continuous casting slab is obtained through slab continuous casting, wherein the thickness of the continuous casting slab is 230mm, the width is 1100-1600 mm, and the length is 9000-11000 mm.
And (3) conveying the fixed-length continuous casting slab produced by steelmaking to a hot rolling heating furnace for reheating, discharging the slab, removing phosphorus, and conveying the slab to a hot continuous rolling unit for rolling. And (3) rolling by controlling a rough rolling mill set and a finish rolling mill set, coiling after laminar cooling, and adopting front-stage cooling for the laminar cooling to obtain qualified hot rolled steel strips, wherein the thickness of the hot rolled steel strips is 2.0-3.0 mm. The hot rolling process control parameters are shown in Table 2.
TABLE 2 Hot Rolling Process control parameters for example steels according to the invention
And (3) uncoiling the hot rolled steel strip again, pickling, performing primary cold rolling in a five-frame tandem CVC+six-roller cold continuous rolling mill, wherein the rolling reduction rate of the cold rolling is 70-76%, and annealing, hot galvanizing, finishing and coiling the steel strip in a rolled hard state through a vertical continuous annealing furnace to obtain a finished GI steel strip with the thickness of 0.5-0.9 mm. The cold rolling and hot galvanizing process parameters are shown in Table 3.
TABLE 3 Cold Rolling and Hot galvanizing Process control parameters for example Steel according to the invention
The hot dip galvanized steel strip obtained by the method was drawn according to a metallic material tensile test method (GB/T228.1), and the mechanical properties are shown in Table 4.
TABLE 4 mechanical Properties of Hot-dip galvanized Steel strips according to an embodiment of the invention
The present invention is not limited to the above embodiments, and any person who can learn the structural changes made under the teaching of the present invention can fall within the scope of the present invention if the present invention has the same or similar technical solutions.
The technology, shape, and construction parts of the present invention, which are not described in detail, are known in the art.
Claims (2)
1. The thin GI high-strength steel strip with the yield strength of 700MPa is characterized by comprising the following chemical components in percentage by mass: c:0.16 to 0.18 percent, si:0.15 to 0.22 percent, mn:1.0 to 1.2 percent, P:0.015 to 0.025 percent, S is less than or equal to 0.03 percent, als:0.03 to 0.05 percent, nb: 0.015-0.025%, and the balance of Fe and unavoidable impurities, and the production method of the GI high-strength steel strip with the thin specification yield strength of 700MPa comprises the following steps:
1) Continuously casting molten steel to obtain a continuous casting plate blank;
2) Heating the continuous casting slab to 1220-1250 ℃, and then carrying out hot rolling, wherein the hot rolling is a two-stage rolling process, rolling is carried out above the austenite recrystallization temperature, and the rough rolling finishing temperature is 1060-1080 ℃; rolling in an austenite non-recrystallization temperature zone, wherein the finish rolling temperature is 860-880 ℃, laminar cooling is performed by adopting front-stage cooling after finish rolling, the coiling temperature is 550-570 ℃, a U-shaped coiling mode is adopted, the coiling temperature of the head and the tail of the steel strip is higher than the coiling temperature of the middle part by 30 ℃, and a hot rolled steel coil with the thickness of 2.0-3.0 mm is obtained by coiling;
3) Cooling the hot rolled steel coil, re-uncoiling, and carrying out pickling, cold rolling and coiling to obtain a cold rolled steel strip with the thickness of 0.5-0.9 mm, wherein the cold rolling reduction rate is 70-76%;
4) Cooling the cold-rolled steel coil, re-uncoiling, annealing by a vertical continuous annealing furnace, hot galvanizing, finishing and coiling to obtain a finished GI steel belt with the thickness of 0.5-0.9 mm, wherein the temperature of an annealing soaking section is 600-610 ℃, the annealing time of the steel belt in the soaking section is 85-100 s, the temperature of the steel belt entering a zinc pot is 470-490 ℃, and the finishing elongation is 0.3-0.5%.
2. The thin gauge 700MPa grade high strength GI steel strip of claim 1, wherein the microstructure of the steel strip is ferrite + pearlite, the yield strength R P0.2 is greater than or equal to 700MPa, the tensile strength R m is greater than or equal to 720MPa, and the elongation after break a 50 is greater than or equal to 6%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310162242.XA CN116179960B (en) | 2023-02-24 | 2023-02-24 | Thin GI high-strength steel strip with 700 MPa-grade yield strength and production method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310162242.XA CN116179960B (en) | 2023-02-24 | 2023-02-24 | Thin GI high-strength steel strip with 700 MPa-grade yield strength and production method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116179960A CN116179960A (en) | 2023-05-30 |
| CN116179960B true CN116179960B (en) | 2024-08-09 |
Family
ID=86452045
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310162242.XA Active CN116179960B (en) | 2023-02-24 | 2023-02-24 | Thin GI high-strength steel strip with 700 MPa-grade yield strength and production method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116179960B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5384206A (en) * | 1991-03-15 | 1995-01-24 | Nippon Steel Corporation | High-strength cold-rolled steel strip and molten zinc-plated high-strength cold-rolled steel strip having good formability and method of producing such strips |
| CN111020437A (en) * | 2019-12-25 | 2020-04-17 | 山东钢铁集团日照有限公司 | Manufacturing method of hot-dip galvanized steel strip with yield strength of above 580Mpa grade |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100896586B1 (en) * | 2007-05-15 | 2009-05-07 | 주식회사 포스코 | High strength cold rolled steel sheet having high yield strength, and process for producing the same |
| CN101660091A (en) * | 2008-08-25 | 2010-03-03 | 鞍钢股份有限公司 | High-strength full-hard hot-dip galvanized steel plate with good surface quality and production method thereof |
| JP5842515B2 (en) * | 2011-09-29 | 2016-01-13 | Ｊｆｅスチール株式会社 | Hot-rolled steel sheet and manufacturing method thereof |
| CN107557668A (en) * | 2017-09-29 | 2018-01-09 | 舞阳钢铁有限责任公司 | TMCP types surrender 345MPa level Weather-resistance bridge steel plates and production method |
| CN108441763B (en) * | 2018-03-23 | 2019-11-19 | 马钢(集团)控股有限公司 | A kind of tensile strength 1000MPa grades of cold rollings galvanizing by dipping high-strength steel and preparation method thereof |
| CN115181888A (en) * | 2021-04-02 | 2022-10-14 | 宝山钢铁股份有限公司 | Low-carbon low-alloy hot-dip aluminum-zinc or zinc-aluminum-magnesium complex phase steel with yield strength of 450MPa and manufacturing method thereof |
| CN113355604B (en) * | 2021-06-25 | 2022-05-24 | 攀钢集团攀枝花钢铁研究院有限公司 | Low-cost 700 MPa-grade hot-dip galvanized complex-phase steel plate and preparation method thereof |
-
2023
- 2023-02-24 CN CN202310162242.XA patent/CN116179960B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5384206A (en) * | 1991-03-15 | 1995-01-24 | Nippon Steel Corporation | High-strength cold-rolled steel strip and molten zinc-plated high-strength cold-rolled steel strip having good formability and method of producing such strips |
| CN111020437A (en) * | 2019-12-25 | 2020-04-17 | 山东钢铁集团日照有限公司 | Manufacturing method of hot-dip galvanized steel strip with yield strength of above 580Mpa grade |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116179960A (en) | 2023-05-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111748745B (en) | 780 MPa-grade cold-rolled hot-galvanized dual-phase steel with high formability and manufacturing method thereof | |
| CN108441763B (en) | A kind of tensile strength 1000MPa grades of cold rollings galvanizing by dipping high-strength steel and preparation method thereof | |
| CN107916363A (en) | A kind of yield strength 550MPa grades of cold-rolled steel sheets and its manufacture method | |
| CN112430787B (en) | Low-yield-ratio high-strength cold-rolled hot-dip galvanized steel plate and manufacturing method thereof | |
| CN111304540A (en) | Cold-rolled steel strip for 280 Mpa-grade automobile structure and manufacturing method thereof | |
| CN114525452B (en) | Hot-dip galvanized low-alloy high-strength steel with yield strength of 700Mpa level and preparation method thereof | |
| CN111961789B (en) | Structural-grade color-coated base material hot-dip galvanized steel plate for thin-specification steel products and manufacturing method thereof | |
| CN111041166A (en) | Cold-rolled steel plate for automobile silencing sheet and production method thereof | |
| CN110629000A (en) | Cold-rolled hot-dip galvanized steel sheet with yield strength of 280MPa and manufacturing method thereof | |
| CN113025882B (en) | Hot-base galvanized ferrite bainite high-strength steel plate and preparation method thereof | |
| CN113718166B (en) | Hot-dip aluminum-zinc steel plate with yield strength of 320MPa and manufacturing method thereof | |
| JP3528716B2 (en) | High-strength cold-rolled steel sheet, high-strength galvanized steel sheet excellent in surface properties and press formability, and manufacturing method thereof | |
| CN108914014B (en) | Cold-rolled high-strength hot-dip galvanized steel plate and preparation method thereof | |
| CN114959481B (en) | Hot-dip galvanized low-alloy high-strength steel with high elongation of 420MPa and production method thereof | |
| CN116179960B (en) | Thin GI high-strength steel strip with 700 MPa-grade yield strength and production method thereof | |
| CN115386782A (en) | Low-cost high-strength galvanized sheet and manufacturing process of sandwich board thereof | |
| CN109881079B (en) | One-steel multi-stage galvanized low-alloy high-strength steel strip and production method thereof | |
| CN113106335A (en) | 800 MPa-grade high-strength weather-resistant girder steel belt and preparation method thereof | |
| CN110541107B (en) | Hot-dip aluminum-zinc steel plate with tensile strength of 600MPa and manufacturing method thereof | |
| CN112813342A (en) | Hot-dip galvanized steel strip for light steel with strength of 600MPa and preparation method thereof | |
| CN112430788A (en) | Hot-dip galvanized steel sheet for 304 stainless steel composite board and manufacturing method thereof | |
| CN115505833B (en) | Hot dip aluminized zinc steel plate with yield strength of 450MPa and manufacturing method thereof | |
| CN116288024B (en) | High-strength hot-base galvanized steel sheet with good forming performance and manufacturing method thereof | |
| JP3508654B2 (en) | High-strength cold-rolled steel sheet for press forming excellent in material uniformity in coil and method for producing the same | |
| CN117327970A (en) | Hot-dip aluminized zinc-plated steel plate with yield strength of 350MPa and manufacturing 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 |