CN113106333A - Low-cost high-strength steel with yield strength of 800Mpa and production method thereof - Google Patents
Low-cost high-strength steel with yield strength of 800Mpa and production method thereof Download PDFInfo
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- CN113106333A CN113106333A CN202110261923.2A CN202110261923A CN113106333A CN 113106333 A CN113106333 A CN 113106333A CN 202110261923 A CN202110261923 A CN 202110261923A CN 113106333 A CN113106333 A CN 113106333A
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- 239000010959 steel Substances 0.000 title claims abstract description 89
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 31
- 238000001816 cooling Methods 0.000 claims abstract description 62
- 238000000034 method Methods 0.000 claims abstract description 40
- 238000005096 rolling process Methods 0.000 claims abstract description 38
- 238000005496 tempering Methods 0.000 claims abstract description 30
- 230000008569 process Effects 0.000 claims abstract description 26
- 238000010438 heat treatment Methods 0.000 claims abstract description 16
- 238000005266 casting Methods 0.000 claims abstract description 12
- 229910052796 boron Inorganic materials 0.000 claims abstract description 8
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 7
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 6
- 239000012535 impurity Substances 0.000 claims abstract description 6
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- 239000007921 spray Substances 0.000 claims description 4
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- 229910001566 austenite Inorganic materials 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 238000001000 micrograph Methods 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
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- 239000003245 coal Substances 0.000 description 3
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- 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
- 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
- C22C38/06—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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- 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 relates to low-cost high-strength steel with yield strength of 800Mpa, which comprises the following elements in percentage by mass: c: 0.07 to 0.09%, Si: 0.10 to 0.25%, Mn: 1.65-1.80%, P is less than or equal to 0.016%, S is less than or equal to 0.010%, Als is more than or equal to 0.015%, Nb: 0.020-0.035%, Cr: 0.20-0.30%, Ti: 0.010-0.025%, B: 0.0010-0.0020%, and the balance of Fe and inevitable residual elements and impurities in the production process. The invention also provides a production method of the low-cost high-strength steel with the yield strength of 800Mpa, which comprises the working procedures of casting blank heating, controlled rolling, air cooling after rolling, controlled cooling and off-line tempering; controlling the air cooling rate to be 1.8-2.8 ℃/s after rolling; and the DQ + ACC is adopted for controlling cooling in the cooling control procedure, the start cooling temperature is more than or equal to 800 ℃, the cooling speed of a DQ section is controlled to be 40-60 ℃/s, the cooling speed of an ACC section is controlled to be 8-15 ℃/s, and the final cooling temperature is controlled to be 60-120 ℃. The method has the advantages of low production cost and simple process flow, the final flatness of the steel plate is controlled within 5mm/2m, and the comprehensive performance meets GB/T16270-.
Description
Technical Field
The invention relates to high-strength steel and a production method thereof, in particular to low-cost high-strength steel with yield strength of 800Mpa and a production method thereof.
Background
With the increasing competition of the coal mine machinery industry, the demand of the coal mine machinery for the steel plate for the low-cost high-strength structure is stronger. At present, steel plates for Q800D high-strength structures with the thickness of 16-25mm are gradually applied to key parts such as top beams, push rods and the like of large hydraulic supports with the thickness of more than 8 meters, so that the whole set of hydraulic support is lightened, and the safety of mine operation is ensured.
The steel plate of the steel grade produced by the domestic medium plate factory mainly comprises two process routes of quenching and tempering and non-quenching and tempering. The quenching and tempering process is simple and controllable, the product performance stability is good, but the disadvantages of long production period, high working procedure and high alloy cost exist. The non-tempering process mainly comprises a thermal mechanical rolling process and a tempering process, the component design is realized by improving the carbon content or adding elements such as Mn, Cr, B and the like, bainite or martensite structures are obtained by utilizing good hardenability and online rapid cooling, and the required mechanical properties are obtained by a proper tempering process. The non-tempering process route has the advantages of short flow, low process cost and the like, but has the problems of poor plasticity and plate shape quality and the like.
The patent application of CN106148822A discloses a method for producing a high-strength steel Q890 medium plate by on-line quenching, a lath martensite and bainite dual-phase structure is obtained by on-line quenching, and the performance meeting the standard requirement is obtained by a proper tempering process, but the patent relates to that a large amount of Mo, Ni and V elements are added into the steel, so that the alloy cost is high.
CN 1102605253A discloses a low-cost high-strength high-toughness steel plate and a production process thereof, wherein the carbon content is controlled to be 0.13-0.17wt%, Mn and B low-cost hardenability elements are matched, and products with strength meeting Q800 series are obtained through proper controlled rolling, controlled cooling and tempering processes. The patent designs that the added alloy of the steel grade is mainly low in cost, and realizes the low-cost production of the Q800 series steel grade, but the patent relates to that the carbon content of the steel grade is 0.13-0.17wt%, and the steel grade has the advantages of high strength of the steel plate after cooling, difficult plate shape control and poor final plasticity of the steel plate while obviously improving the hardenability of the steel plate.
Disclosure of Invention
The invention aims to solve the technical problem of providing the low-cost high-strength steel with the yield strength of 800MPa, wherein the comprehensive performance meets GB/T16270-; the invention also provides a production method of the low-cost high-strength steel with the yield strength of 800MPa, which has the advantages of low production cost, simple process flow and capability of controlling the final flatness of the steel plate within 5mm/2m and solving the defects of the background technology.
The technical scheme for solving the technical problems is as follows:
the low-cost high-strength steel with yield strength of 800MPa comprises the following elements in percentage by mass: c: 0.07 to 0.09%, Si: 0.10 to 0.25%, Mn: 1.65-1.80%, P is less than or equal to 0.016%, S is less than or equal to 0.010%, Als is more than or equal to 0.015%, Nb: 0.020-0.035%, Cr: 0.20-0.30%, Ti: 0.010-0.025%, B: 0.0010-0.0020%, and the balance of Fe and inevitable residual elements and impurities in the production process.
In the low-cost high-strength steel with yield strength of 800MPa, the mass percentages of the elements in the steel are preferably as follows: c: 0.07 to 0.09%, Si: 0.10 to 0.20%, Mn: 1.70-1.80%, P is less than or equal to 0.015%, S is less than or equal to 0.008%, Als: 0.015-0.035%, Nb: 0.020-0.030%, Cr: 0.22-0.28%, Ti: 0.010-0.020%, B: 0.0010-0.0016%, and the balance of Fe and inevitable residual elements and impurities in the production process.
A production method of low-cost high-strength steel with yield strength of 800MPa comprises the working procedures of casting blank heating, controlled rolling, air cooling after rolling, controlled cooling and off-line tempering; controlling the air cooling rate after rolling to be 1.8-2.8 ℃/s;
the controlled cooling process adopts DQ + ACC to control cooling, the start cooling temperature is more than or equal to 800 ℃, the cooling speed of a DQ section is controlled to be 40-60 ℃/s, the cooling speed of an ACC section is controlled to be 8-15 ℃/s, and the final cooling temperature is controlled to be 60-120 ℃.
According to the production method of the low-cost high-strength steel with the yield strength of 800MPa, side water sprays for DQ and ACC sections need to cover the width of the whole roller way, the side water sprays are distributed at an included angle of 10-12 degrees with the upper surface of a steel plate, the water quantity ratio of upper and lower collecting pipes of the DQ section is controlled to be 1.7-1.9, the water quantity ratio of upper and lower collecting pipes of the ACC section is 2.0-2.2, the inclination of straightening rolls at the inlet and the outlet of a straightening machine is controlled to be 5-7mm, and the straightening force is guaranteed to be over 160.
The production method of the low-cost high-strength steel with the yield strength of 800MPa comprises an off-line tempering process, wherein the tempering temperature is 500 +/-5 ℃, the temperature is kept for 24-36 minutes, and the tempered steel plate is air-cooled to the room temperature.
According to the production method of the low-cost high-strength steel with the yield strength of 800MPa, the controlled rolling design is a two-stage rolling process, the initial rolling temperature is 1060-1120 ℃, the thickness of the steel plate is more than or equal to 3a when the temperature is controlled, the thickness of the steel plate is less than or equal to 880 a when the temperature is controlled, and the final rolling temperature is controlled within the range of 850-880 ℃.
According to the production method of the low-cost high-strength steel with the yield strength of 800MPa, the surface temperature of the casting blank at the end of heating in the casting blank heating process is controlled within the range of 1210-1250 ℃, and the heating time is more than or equal to 240 min.
According to the invention, the mechanical property requirement of GB/T16270-one 2009 standard on Q800D is met by low-carbon component design, reducing the addition of precious alloys such as Mo and Ni and combining specific rolling, air cooling after rolling, cooling and tempering heat treatment processes. The steel rolling and heat treatment process is simple and easy to implement, the addition of noble alloy elements is reduced as much as possible on the premise of ensuring the mechanical property, and the low-cost manufacture of Q800D is realized.
The invention ensures that the strength of the Q800D steel plate meets GB/T16270-2009, simultaneously realizes the low-cost manufacture of the steel plate, and the design of production process parameters is mainly based on the following principle:
a. controlling the surface temperature of the slab after being heated by the heating furnace to be 1210-1250 ℃, ensuring that the temperature before the casting blank is descaled after being heated is higher than the melting point 1170 ℃ of ferrous silicate, and facilitating descaling of a descaling box; in the temperature range, the machinability of the casting blank in the first rolling process can be improved, and the production efficiency is improved;
b. the two-stage initial rolling temperature is set below 880 ℃ to ensure that the deformation is carried out in a non-recrystallization temperature zone, so that a partial recrystallization temperature zone is avoided, the thickness of the steel plate in the two-stage rolling is controlled to be more than 3 times of the thickness of a finished product, the accumulated reduction rate can be more than or equal to 67 percent, so that enough dislocation can be obtained, the high-strength steel plate is repeatedly rolled and deformed in the non-recrystallization zone for multiple times, and a large amount of dislocation, deformation zones and microalloy element precipitates with various sizes are accumulated in a deformed structure after the steel plate is rolled. And controlling the final rolling temperature within the range of 850-880 ℃, controlling the air cooling speed from the rolled steel plate to a cooling section to be 1.8-2.8 ℃/s in combination with the adjustment of the steel plate throwing speed, the roller way and the pre-straightening biting speed after rolling, carrying out air cooling on the steel plate according to the cooling speed, rearranging or eliminating the deformation dislocation in the steel plate in the air cooling process, and forming a dislocation cellular substructure in the deformation austenite. With the continuous addition of deformation dislocation, included angles among sub-crystals increase, and trace elements such as Nb, Ti, B and the like are subjected to unbalanced segregation and precipitation on the boundary of a cellular structure consisting of the dislocation.
c. After air cooling, the steel plate is directly and rapidly cooled, the open cooling temperature is more than or equal to 800 ℃, so that dislocation cellular sub-structures formed in the supercooled austenite of the steel plate can be prevented from being combined in advance, and the phase change effect after rapid cooling is inhibited. Since there are a large number of substructures and precipitates in the deformed grains, their interfaces with the matrix become favorable sites for phase transformation. The cooling speed of the DQ section is controlled to be 40-60 ℃/s, new phases are firstly formed on the DQ section in the cooling process, and the prior formed intracrystalline bainite divides original austenite grains into different regions. In the further cooling process, bainite or martensite phase transformation occurs in the substructure, the lath length is hindered by the subboundary and early bainite formation, so that the lath structure is thinner and shorter, the structure is ultra-fine, and the strength of the steel plate can be greatly increased. The ACC section is controlled at 8-15 ℃/s, and the final cooling temperature is controlled at 60-120 ℃, so that the full transformation of bainite or martensite can be further promoted, and the strength of the steel plate is improved.
In order to ensure that the steel plate reaches the cooling speed, the steel plate must be cooled by using an ultra-large water quantity, the accumulated water on the surface of the steel plate can be avoided by side water spraying at a proper angle and in a sufficient quantity, the cooling uniformity of the steel plate is ensured, and the uneven cooling stress is weakened. In the water cooling process, the transformation from a super-cooled austenite structure to bainite and martensite occurs, the crystal lattice structure is transformed from a face-centered cubic or tetragonal direction, the expansion rate is 8.9% in theory during the phase transformation, the water quantity ratio of upper and lower headers of DQ and ACC sections is reasonably set, the phenomenon that the volume expansion of the upper and lower surfaces of a steel plate is uneven can be effectively avoided, the steel plate is warped upwards or buckled downwards in the width direction, reasonable and enough straightening force is applied to the steel plate after cold, the steel plate can generate enough plastic strain to offset the uneven stress of the steel plate after cooling, the springback phenomenon is avoided, and a foundation is laid for the shape of the finished steel plate after tempering.
d. In the tempering process, the tempering temperature is controlled to be 500 +/-5 ℃, the tempering time is controlled to be 24-36 minutes, the Q800D tempering brittleness area under the component process is avoided at 500 +/-5 ℃, in addition, the tempering time is controlled to be 24-36 minutes, on one hand, the internal stress of the hot-rolled steel plate can be eliminated, on the other hand, the fine carbides precipitated in the hot-rolled structure are promoted to ensure the strength of the steel plate, and the strength loss of the steel plate caused by the further growth of the carbides is avoided.
The invention has the beneficial effects that:
the invention obtains an ideal mixed tempering structure of ferrite lath bundles and fine carbides through low-carbon composition design and reasonable design of rolling, air cooling speed after rolling, air cooling starting temperature, cooling speed of a controlled cooling section, final cooling temperature and tempering process, realizes low-cost manufacture of Q800D on the premise that various performances meet GB/T16270-plus-energy 2009, has simple process flow, controls the final flatness of a steel plate within 5mm/2m, completely meets the use requirements of the coal machine industry on low cost and light weight, and has stronger competitive advantages in similar enterprises.
Drawings
FIG. 1 is a 500 × micrograph of Q800D produced in example 1;
FIG. 2 is a 500 × micrograph of Q800D produced in example 2;
FIG. 3 is a 500 × micrograph of Q800D produced in example 3;
FIG. 4 is a 500 × micrograph of Q800D produced in example 4;
FIG. 5 is a 500 × micrograph of Q800D produced in example 5;
fig. 6 is a 500 x micrograph of Q800D produced in example 6.
Detailed Description
The invention relates to a low-cost high-strength steel with yield strength of 800MPa, which comprises the following elements in percentage by mass: c: 0.07-0.09%; si: 0.10 to 0.25%, preferably 0.10 to 0.20%; mn: 1.65-1.80%, preferably 1.70-1.80%; p is less than or equal to 0.016 percent, preferably less than or equal to 0.015 percent; s is less than or equal to 0.010 percent, preferably less than or equal to 0.008 percent; als is more than or equal to 0.015 percent, and preferably 0.015 to 0.035 percent; nb: 0.020-0.035%, preferably 0.020-0.030%; cr: 0.20 to 0.30%, preferably 0.22 to 0.28%; ti: 0.010-0.025%, preferably 0.010-0.020%; b: 0.0010-0.0020%, preferably 0.0010-0.0016%; the others are Fe and residual elements and impurities inevitable in the production process.
The invention relates to a production method of low-cost high-strength steel with yield strength of 800MPa, which comprises the process steps of casting blank heating, controlled rolling, air cooling after rolling, controlled cooling and off-line tempering;
the surface temperature of the casting blank at the end of heating in the casting blank heating process is controlled within the range of 1210-1250 ℃, and the heating time is more than or equal to 240 min.
Controlling the rolling temperature in the rolling process to be 1060-1120 ℃, designing a two-stage rolling process, and controlling the rolling temperature to be more than or equal to 3 a: a is the thickness of a steel plate finished product, the finishing temperature is not more than 880 ℃, and the finishing temperature is controlled within the range of 820-850 ℃.
After rolling, the steel plate is controlled to have an air cooling speed of 1.8-2.8 ℃/s from the rolled steel plate to a cooling section, a DQ section cooling speed of 40-60 ℃/s, an ACC section of 8-15 ℃/s and a final cooling temperature of 60-120 ℃ by adjusting the steel throwing speed, the roller way speed and the pre-straightening biting speed.
And transferring the cold steel plate to a tempering furnace, tempering at 500 +/-5 ℃, preserving the heat for 24-36 minutes, and air cooling the tempered steel plate to room temperature. The purpose of low-cost production of Q800D is realized.
The present invention is further illustrated by the following specific examples 1 to 6:
the Q800D finished steel products with the thickness specification of 16-25mm are produced in examples 1-6, the Q800D finished steel product with the thickness specification of 16-25mm tested according to the method has the chemical components with the mass percentage (wt%) shown in Table 1, the rolling and cooling process is shown in Table 2, and the mechanical property detection results are shown in Table 3:
TABLE 1 chemical composition (wt%, balance Fe) of each example
TABLE 2 controlled Rolling + (DQ + ACC) + tempering procedure parameters for the examples
TABLE 3 mechanical Properties of the examples
Examples 1-6 show that the mechanical properties of the produced Q800D-grade steel plate completely meet the requirements of the national standard GB/T16270-; as can be seen from FIGS. 1 to 6, the microstructures of the steel sheets of the examples are mixed and tempered structures of ferrite lath bundles and fine carbides, the flat prior austenite grains are clearly visible, and the prior austenite grains have fine lath structures.
Claims (7)
1. A low-cost high-strength steel with yield strength of 800MPa is characterized in that: the steel comprises the following elements in percentage by mass: c: 0.07 to 0.09%, Si: 0.10 to 0.25%, Mn: 1.65-1.80%, P is less than or equal to 0.016%, S is less than or equal to 0.010%, Als is more than or equal to 0.015%, Nb: 0.020-0.035%, Cr: 0.20-0.30%, Ti: 0.010-0.025%, B: 0.0010-0.0020%, and the balance of Fe and inevitable residual elements and impurities in the production process.
2. A low cost high strength steel with a yield strength of 800MPa as claimed in claim 1 wherein: the steel comprises the following elements in percentage by mass: c: 0.07 to 0.09%, Si: 0.10 to 0.20%, Mn: 1.70-1.80%, P is less than or equal to 0.015%, S is less than or equal to 0.008%, Als: 0.015-0.035%, Nb: 0.020-0.030%, Cr: 0.22-0.28%, Ti: 0.010-0.020%, B: 0.0010-0.0016%, and the balance of Fe and inevitable residual elements and impurities in the production process.
3. A production method of low-cost high-strength steel with yield strength of 800MPa comprises the working procedures of casting blank heating, controlled rolling, air cooling after rolling, controlled cooling and off-line tempering; the method is characterized in that: controlling the air cooling rate after rolling to be 1.8-2.8 ℃/s;
the controlled cooling process adopts DQ + ACC to control cooling, the start cooling temperature is more than or equal to 800 ℃, the cooling speed of a DQ section is controlled to be 40-60 ℃/s, the cooling speed of an ACC section is controlled to be 8-15 ℃/s, and the final cooling temperature is controlled to be 60-120 ℃.
4. A method of producing a low cost high strength steel with a yield strength of 800MPa as claimed in claim 3 wherein: the side water sprays for the DQ section and the ACC section need to cover the width of the whole roller way, the side water sprays and the upper surface of a steel plate form an included angle of 10-12 degrees, the water quantity ratio of an upper collecting pipe and a lower collecting pipe of the DQ section is controlled to be 1.7-1.9, the water quantity ratio of the upper collecting pipe and the lower collecting pipe of the ACC section is 2.0-2.2, the inclination of straightening rolls at an inlet and an outlet of a straightening machine is controlled to be 5-7mm, and the straightening force is guaranteed to.
5. A method of producing a low cost high strength steel with a yield strength of 800MPa as claimed in claim 3 wherein: in the off-line tempering process, the tempering temperature is 500 +/-5 ℃, the temperature is kept for 24-36 minutes, and the steel plate is air-cooled to the room temperature after tempering.
6. A method of producing a low cost high strength steel with a yield strength of 800MPa as claimed in claim 3 wherein: the controlled rolling is designed into a two-stage rolling process, the initial rolling temperature is 1060-1120 ℃, the thickness of the steel plate to be rolled is more than or equal to 3a, a is the thickness of the finished steel plate, the final temperature is less than or equal to 880 ℃, and the final rolling temperature is controlled within the range of 850-880 ℃.
7. A method of producing a low cost high strength steel with a yield strength of 800MPa as claimed in claim 3 wherein: the surface temperature of the casting blank at the end of heating in the casting blank heating process is controlled within the range of 1210-1250 ℃, and the heating time is more than or equal to 240 min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110261923.2A CN113106333B (en) | 2021-03-10 | 2021-03-10 | Low-cost high-strength steel with yield strength of 800Mpa and production method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110261923.2A CN113106333B (en) | 2021-03-10 | 2021-03-10 | Low-cost high-strength steel with yield strength of 800Mpa and production method thereof |
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| CN114262845A (en) * | 2021-12-06 | 2022-04-01 | 邯郸钢铁集团有限责任公司 | 500 Mpa-grade thin-specification bridge plate and production method thereof |
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