WO2024041533A1 - 100-kg-grade cold-rolled low-alloy annealed dual-phase steel and manufacturing method therefor - Google Patents

100-kg-grade cold-rolled low-alloy annealed dual-phase steel and manufacturing method therefor Download PDF

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WO2024041533A1
WO2024041533A1 PCT/CN2023/114258 CN2023114258W WO2024041533A1 WO 2024041533 A1 WO2024041533 A1 WO 2024041533A1 CN 2023114258 W CN2023114258 W CN 2023114258W WO 2024041533 A1 WO2024041533 A1 WO 2024041533A1
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cold
phase steel
rolled low
dual
alloy annealed
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PCT/CN2023/114258
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French (fr)
Chinese (zh)
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李伟
朱晓东
王利
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宝山钢铁股份有限公司
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Publication of WO2024041533A1 publication Critical patent/WO2024041533A1/en

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    • 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
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium

Definitions

  • the present invention relates to a metal material and a manufacturing method thereof, in particular to a 100-kg cold-rolled low-alloy annealed dual-phase steel and a manufacturing method thereof.
  • the publication number is CN109280854A
  • the publication date is January 29, 2019,
  • the Chinese patent document titled "980MPa grade low carbon cold-rolled dual-phase steel and its preparation method" discloses a 980MPa grade low carbon cold-rolled dual-phase steel.
  • Phase steel This technical solution aims to solve the existing technical problems of high production cost and difficulty in production of 980MPa grade cold-rolled dual-phase steel.
  • the publication number is CN107043888A
  • the publication date is August 15, 2017,
  • the Chinese patent document titled "A 980MPa grade cold-rolled dual-phase steel plate with excellent cold bending performance and its preparation method” discloses a The chemical composition and weight percentage of 980MPa grade cold-rolled dual-phase steel plate are: C 0.10 ⁇ 0.12%; Si 0.45 ⁇ 0.65%; Mn 2.4 ⁇ 2.6%; Cr 0.35 ⁇ 0.45%; Nb 0.05 ⁇ 0.075%; Ti 0.06 ⁇ 0.10%; Als 0.055 ⁇ 0.075%; P ⁇ 0.008%; S ⁇ 0.002%; N ⁇ 0.003%, the balance is Fe and inevitable impurities.
  • the dual-phase steel plate prepared by this technical solution has excellent mechanical properties, the content of Cr, Nb, and Ti elements designed to be added to the steel is relatively high.
  • the present invention hopes to develop a 100-kg cold-rolled low-alloy annealed dual-phase steel that is both economical and has excellent mechanical properties.
  • One of the purposes of the present invention is to provide a 100 kg-grade cold-rolled low-alloy annealed dual-phase steel.
  • the 100-kg grade cold-rolled low-alloy annealed dual-phase steel has both economy and excellent mechanical properties. It does not add Mo or Cr. Under the premise of eliminating elements, it still has high strength and excellent elongation and bending properties. Its yield strength is ⁇ 550MPa; its tensile strength is ⁇ 1000MPa; A 50 gauge fracture elongation is ⁇ 12%; 90-degree bending performance R/t ⁇ 1.0, has very good promotion prospects and application value.
  • the 100 kg grade refers to the tensile strength of the steel ⁇ 980MPa
  • the 1000MPa grade refers to the tensile strength of the steel ⁇ 1000MPa.
  • the present invention provides a 100 kg cold-rolled low-alloy annealed dual-phase steel, which contains Fe and inevitable impurity elements, and also contains the following chemicals in mass percentages: element:
  • microstructure of the 100-kg cold-rolled low-alloy annealed dual-phase steel is martensite + ferrite.
  • the mass percentage content of each chemical element is:
  • the inventor uses a composition system mainly composed of C-Si-Mn to ensure that the obtained cold-rolled low-alloy annealed dual-phase steel can reach 1000MPa strength.
  • the chemical composition design of this dual-phase steel no precious alloy elements such as Mo and Cr are added, which can effectively ensure economy; in addition, the present invention also adds and utilizes a trace amount of high-hardenability element B in the chemical composition design.
  • trace amounts of Nb and Ti are added to the steel to inhibit the growth of austenite grains and effectively refine the grains.
  • adding C element can improve the strength of the steel and increase the hardness of martensite. If the mass percentage of C in the steel is less than 0.1%, the strength of the steel plate will be affected and is not conducive to the formation and stability of austenite; and when the mass percentage of the C element in the steel is higher than 0.13% , it will cause the martensite hardness to be too high and the grain size to be coarse, which is not conducive to the formability of the steel plate. At the same time, the carbon equivalent is too high, which is not conducive to welding.
  • the mass percentage of the C element is specifically controlled to 0.1% ⁇ C ⁇ 0.13%, for example, the C element
  • the mass percentage can be 0.101%, 0.105%, 0.11%, 0.115%, 0.12%, 0.125%, 0.13% or within the range of any two of the aforementioned values.
  • Si In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, adding Si element to the steel can improve the hardenability of the steel, and the solid solution Si in the steel can affect the interaction of dislocations, thereby Increasing the work hardening rate can appropriately increase the elongation of dual-phase steel and is beneficial to obtaining better Formability.
  • the Si element content in steel should not be too high. When the mass percentage of Si element in steel is too high, it will be detrimental to the control of the surface quality of the steel plate.
  • the mass percentage content of Si element is controlled between 0.5% and 0.8%, for example, Si element
  • the mass percentage can be 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8% or within the range of any two of the aforementioned values.
  • Mn In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, adding Mn element is not only beneficial to improving the hardenability of the steel, but can also effectively improve the strength of the steel plate.
  • the mass percentage of the Mn element in the steel is less than 1.6%, the strength of the steel plate is insufficient; and when the mass percentage of the Mn element in the steel is higher than 1.8%, the strength of the steel plate is too high, which will cause it to form Performance degrades.
  • the mass percentage of Mn element is controlled between 1.6% and 1.8%, for example, Mn element
  • the mass percentage may be 1.6%, 1.63%, 1.65%, 1.68%, 1.7%, 1.73%, 1.75%, 1.78%, 1.8% or within the range of any two of the aforementioned values.
  • the addition of Al element can play a deoxidizing effect and refine the grains.
  • the lower the content of Al element in steel the more beneficial it is to the castability of smelting.
  • the mass percentage content of Al element is controlled between 0.01% and 0.03%.
  • the mass percentage content of Al element can be 0.01%, 0.015%, 0.02%, 0.025%, 0.03% or within the range of any two of the aforementioned values.
  • the Nb element is an important element for refining grains.
  • the strain-induced precipitate phase can significantly reduce the recrystallization temperature of deformed austenite through particle pinning and sub-grain boundaries, providing nucleation particles, which has an obvious effect on refining grains; in addition, During the continuous annealing austenitization process, the undissolved carbon and nitride material points in the soaking will prevent the coarsening of the soaking austenite grains through the particle pinning grain boundary mechanism, thereby effectively refining the grains.
  • the mass percentage of Nb element is specifically controlled between 0.01 and 0.03%, for example, Nb
  • the mass percentage of the element can be 0.01%, 0.015%, 0.02%, 0.025%, 0.03% or within the range of any two of the aforementioned values.
  • the mass percentage of the Nb element can be further preferably controlled between 0.015% and 0.025%.
  • the added strong carbide-forming element Ti also shows a strong effect of inhibiting austenite grain growth at high temperatures.
  • the addition of Ti element also helps to refine the grains. Therefore, in order to exert the beneficial effects of the Ti element, in the present invention, the mass percentage content of the Ti element is specifically controlled between 0.01% and 0.03%.
  • the mass percentage content of the Ti element can be 0.01%, 0.015%, and 0.02 %, 0.025%, 0.03% or within the range of any two of the aforementioned values.
  • the mass percentage of the Ti element can be further preferably controlled between 0.015% and 0.025%.
  • adding B element is not only beneficial to improving the hardenability of the steel, but can also effectively improve the strength of the steel plate.
  • the mass percentage of the B element in the steel is less than 0.0020%, it will also cause the strength of the steel plate to be insufficient; and when the mass percentage of the B element in the steel is higher than 0.0030%, it will also cause the strength of the steel plate to be insufficient. Too high, and its molding performance will be reduced. Therefore, in the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the mass percentage content of the B element is controlled between 0.0020 and 0.0030%. For example, the mass percentage content of the B element can be 0.0020%. , 0.0023%, 0.0025%, 0.0028%, 0.0030% or within the range of any two of the aforementioned values.
  • the dual-phase steel designed by the present invention does not add precious alloy elements such as Mo and Cr, and it has very excellent economic efficiency.
  • its chemical composition design needs to ensure the alloy addition content of C, Mn, and B to provide sufficient Hardenability.
  • the content of C, Mn, and B alloy elements in this dual-phase steel also needs to be controlled at an upper limit to ensure excellent welding performance and formability, and to avoid the strength exceeding the upper limit.
  • P element, S element and N element are all impurity elements in the steel.
  • the MnS formed by the S element will seriously affect the formability of the steel, while the N element can easily cause cracks or bubbles on the surface of the slab. Therefore, when technical conditions permit, in order to obtain To obtain steel with better performance and better quality, the content of impurity elements in the steel should be reduced as much as possible, and the P, S, and N elements in the steel should be specifically controlled to meet: P ⁇ 0.012%, S ⁇ 0.0025%, N ⁇ 0.005%.
  • the mass percentage of P element is 0.001 to 0.012%, and/or the mass percentage of S element is 0.001 ⁇ 0.0025%, and/or the mass percentage of N element is 0.001 ⁇ 0.005%.
  • the mass percentage content of each chemical element satisfies at least one of the following items:
  • the volume percentage content of martensite is ⁇ 60%.
  • the volume percentage content of martensite can be 60%, 65%, 70%, 75%, 80%, 85%, 90% or within the range of any two of the aforementioned values.
  • the hardenability factor YQ is 2.0, 2.1, 2.2, 2.3, 2.4, or within the range of any two of the foregoing values.
  • the composite effect of B element and Mn element can enable the steel to achieve better strength effects.
  • the present invention utilizes the comprehensive hardenability of Mn-B and adds an appropriate amount of B to further reduce the alloy design amount of Mn, thereby having It is conducive to cost reduction and is more conducive to improving the manufacturability of on-site production.
  • the particle size of both martensite and ferrite is not greater than 5 microns.
  • the particle size of martensite can be 3.5 microns, 3.8 microns, 4 microns, 4.2 microns, 4.5 microns, 4.8 microns, 5 microns or within the range of any two of the aforementioned values
  • the particle size of ferrite can be 3.5 micron, 3.8 micron, 4 micron, 4.2 micron, 4.5 micron, 4.8 micron, 5 micron or within the range of any two of the aforementioned values.
  • the microhardness difference ⁇ HV of martensite and ferrite is ⁇ 150.
  • martensite and ferrite The microhardness difference ⁇ HV is 90, 100, 110, 120, 130, 140, 150 or within the range of any two of the aforementioned values.
  • the yield strength of the 100 kg cold-rolled low-alloy annealed dual-phase steel of the present invention is 550MPa, 600MPa, 650MPa, 700MPa or within the range of any two of the aforementioned values.
  • the tensile strength of the 100 kg grade cold-rolled low-alloy annealed dual-phase steel of the present invention is 1000MPa, 1020MPa, 1040MPa, 1060MPa, 1080MPa, 1100MPa or within the range of any two of the aforementioned values.
  • the 100 kg grade cold rolled low alloy annealed dual phase steel of the present invention has an A 50 gauge elongation at break of 12%, 13%, 14%, 15%, 16%, 17% or at Within the range of any two of the aforementioned values.
  • the 90-degree bending property R/t of the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, or any two of the aforementioned values. within the range.
  • another object of the present invention is to provide a method for manufacturing the above-mentioned 100 kg-grade cold-rolled low-alloy annealed dual-phase steel.
  • the manufacturing method is convenient and simple to implement.
  • the 100-kg grade cold-rolled low alloy produced by the manufacturing method Annealed dual-phase steel has high strength and excellent elongation and bending properties. Its yield strength is ⁇ 550MPa, tensile strength is ⁇ 1000MPa, A 50 gauge fracture elongation is ⁇ 12%, and 90-degree bending performance R/t ⁇ 1.0.
  • the present invention proposes a method for manufacturing the above-mentioned 100 kg cold-rolled low-alloy annealed dual-phase steel, which includes the steps:
  • Hot rolling first heat the continuous casting billet to 1160 ⁇ 1190°C, keep it warm for more than 150min, such as 150 ⁇ 250min, and then perform hot rolling and final rolling at 850 ⁇ 890°C. After rolling, the speed is 30 ⁇ 80°C/s. Rapid cooling; then coiling, the coiling temperature is 500 ⁇ 540°C, and air cooling after coiling;
  • the annealing soaking temperature is 825 ⁇ 855°C
  • the annealing time is 40 ⁇ 200s
  • the rapid cooling starting temperature at a speed of 3 ⁇ 5°C/s
  • the ending temperature of fast cooling is 265 ⁇ 290°C
  • the annealing soaking temperature is 830 to 840°C.
  • the obtained grain size is made smaller, the mechanical properties of the obtained steel are moderate, and the formability is better , the annealing soaking temperature can be further preferably controlled between 830-840°C.
  • step (3) the cold rolling reduction rate is controlled to 50% to 70%.
  • step (5) the tempering temperature is controlled to be 265-290°C, and the tempering time is controlled to be 100-400 s.
  • step (6) the flattening reduction rate is controlled to be ⁇ 0.3%, such as 0.1 to 0.3%.
  • the 100-kg cold-rolled low-alloy annealed dual-phase steel and its manufacturing method according to the present invention have the following advantages and beneficial effects:
  • the present invention has developed a new 100-kg cold-rolled low-alloy annealed dual-phase steel. Through reasonable chemical composition design and optimized manufacturing processes, it can be obtained without adding silicon alloy elements such as Mo and Cr. A steel plate with a martensite + ferrite dual-phase structure reaching 1000MPa strength; this fine and uniform martensite + ferrite dual-phase structure can further ensure that the steel has excellent elongation and bending properties, and has better Formability.
  • the 100-kg cold-rolled low-alloy annealed dual-phase steel designed and prepared by the present invention not only has good economy, but also has high strength and excellent elongation and bending performance characteristics, with a yield strength of ⁇ 550MPa and a tensile strength of ⁇ 550MPa. ⁇ 1000MPa, A 50 gauge breaking elongation ⁇ 12%, 90 degree bending performance R/t ⁇ 1.0.
  • the 100-kg cold-rolled low-alloy annealed dual-phase steel is simple to produce and prepare. It has very good promotion prospects and application value and can effectively meet the needs of the market and users.
  • Table 1-1 lists the 100 kg cold-rolled low-alloy annealed dual-phase steels of Examples 1-6 and the comparative examples. The mass percentage ratio of each chemical element designed for 1-14 comparative steel.
  • Table 1-2 lists the values of the hardenability factor Y Q of the 100 kg cold-rolled low-alloy annealed dual-phase steel of Examples 1-6 and the comparative steel of Comparative Examples 1-14.
  • Hot rolling The continuous casting billet is first heated to 1160 ⁇ 1190°C, kept warm for more than 150 minutes, and then hot rolled and finished at 850 ⁇ 890°C. After rolling, it is rapidly cooled at a speed of 30 ⁇ 80°C/s; then Carry out coiling and control the coiling temperature to 500 ⁇ 540°C. After coiling, air cool.
  • Annealing Control the annealing soaking temperature to 825-855°C, or preferably between 830-840°C, control the annealing time to 40-200s, and then cool to fast at a speed of 3-5°C/s.
  • the cooling start temperature is then rapidly cooled at a speed of 40 to 100°C/s, where the quick cooling start temperature is 735 to 760°C, and the quick cooling end temperature is 265 to 290°C.
  • Tempering Control the tempering temperature to 265 ⁇ 290°C and the tempering time to 100 ⁇ 400s.
  • Comparative Examples 1-14 also adopt the proportioning scheme of Table 1-1 and Table 1-2 and are prepared in combination with the above process flow, in order to highlight the superiority of the technical solution of the present invention, the designed The comparative steel materials of Comparative Examples 1-14 all have parameters in chemical composition and/or related manufacturing processes that do not meet the design requirements of the present invention.
  • the chemical compositions of the comparative steels in Comparative Examples 1-6 all have parameters that fail to meet the design requirements of the present invention; while the chemical compositions of the steel types corresponding to Comparative Examples 7-14 meet the design requirements of the present invention, but the relevant There are parameters in the process parameters that fail to meet the design specifications of the present invention.
  • Table 2-1 and Table 2-2 list the 100 kg cold-rolled low alloy annealed dual-phase steel of Examples 1-6 and the comparative steel of Comparative Examples 1-14 in the above process steps (1)-(6). specific process parameters.
  • the inventor took samples of the finished dual-phase steels of Examples 1-6 and Comparative Examples 1-14, respectively, to Corresponding sample steel plates were obtained, and the microstructure of the sample steel plates of each embodiment and comparative example was observed and analyzed using an optical microscope. It was observed that the 100 kg cold-rolled low alloy annealed dual-phase steel of Examples 1-6 and the comparative example The microstructure of the comparative steel plates 1-14 is all martensite + ferrite.
  • the inventor further analyzed the microstructure of the steel plates of each example and comparative example to obtain the martensite phase proportion and martensite particle size in the microstructure of the steel plates of examples 1-6 and comparative examples 1-14.
  • the relevant test results are listed in Table 3 below.
  • the phase ratio refers to the proportion of each phase in the structure measured using the area method
  • the particle size refers to the grain size of each structure, based on the average value in the transverse and longitudinal directions.
  • the phase ratio and particle size were observed using an optical microscope, and the phase ratio and particle size were measured using the analysis software that comes with the optical microscope.
  • Microhardness was measured using a Webster microhardness tester.
  • the microstructure of the 100 kg cold-rolled low-alloy annealed dual-phase steel prepared in Examples 1-6 is martensite + ferrite, and its martensitic
  • the volume percentage content (phase ratio) of the body is between 62-82%, its martensite particle size is between 3.9-4.7 ⁇ m, its ferrite particle size is between 4.0-4.6 ⁇ m, martensite and iron
  • the microhardness difference ⁇ HV of the body is between 95-115.
  • the 100 kilogram grade cold-rolled low-alloy annealed dual-phase steel of Examples 1-6 and the prepared steel of Comparative Examples 1-14 were Sampling of comparative steel materials was carried out to obtain corresponding sample steel plates. And conduct mechanical property tests on the obtained sample steel plates of Examples 1-6 and Comparative Examples 1-14 to obtain the mechanical property data of the steel materials of Examples 1-6 and Comparative Examples 1-14, and list the relevant test results. In Table 4 below.
  • Tensile test test Use the GB/T228-2010 room temperature tensile test method for metal materials to detect the yield strength, tensile strength and A 50 gauge fracture of the steel materials obtained in Examples 1-6 and Comparative Examples 1-14. elongation. Among them, the A 50 gauge elongation at break represents: the elongation at break when the parallel length*width of the tensile specimen is 50mm*25mm.
  • Table 4 lists the mechanical property test results of the 100 kg cold-rolled low-alloy annealed dual-phase steel of Examples 1-6 and the comparative steel of Comparative Examples 1-14.
  • Kilogram force is kilogram force, which is a common unit of force.
  • the 100 kg cold-rolled low-alloy annealed dual-phase steel of Examples 1-6 prepared using the technical solution designed by the present invention has quite excellent mechanical properties, and its yield strength is Between 585-655MPa, the tensile strength is between 1002-1054MPa, its A 50 gauge elongation at break is between 12.7-15.5%, and the 90-degree bending performance R/t is between 0.6-1.0.
  • the dual-phase steels in each embodiment achieved a tensile strength greater than 1000MPa without adding precious alloy elements such as Mo and Cr. They are all 100-kg cold-rolled low-alloy annealed dual-phase steels and have good Elongation and bending properties.
  • the present invention obtains dual-phase steel with both low cost and excellent mechanical properties, which obtains a tensile strength greater than 1000MPa. , while having good elongation and bending characteristics.

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Abstract

Disclosed in the present invention is a 100-kg-grade cold-rolled low-alloy annealed dual-phase steel, which comprises Fe and inevitable impurities, and further comprises the following chemical elements in percentages by mass: 0.1%<C≤0.13%, Si: 0.5-0.8%, Mn: 1.6-1.8%, Al: 0.01-0.03%, Nb: 0.01-0.03%, Ti: 0.01-0.03%, and B: 0.0020-0.0030%, wherein Mo and Cr are not included in the chemical elements thereof. The microstructure of the 100-kg-grade cold-rolled low-alloy annealed dual-phase steel is martensite + ferrite. Accordingly, further disclosed in the present invention is a manufacturing method for the 100-kg-grade cold-rolled low-alloy annealed dual-phase steel. A 100-kg-grade cold-rolled low-alloy annealed dual-phase steel obtained by using the manufacturing method not only has good economical performance, but also has high strength, a good ratio of elongation and good bending performance.

Description

一种100公斤级冷轧低合金退火双相钢及其制造方法A 100kg grade cold-rolled low-alloy annealed dual-phase steel and its manufacturing method 技术领域Technical field
本发明涉及一种金属材料及其制造方法，尤其涉及一种100公斤级冷轧低合金退火双相钢及其制造方法。The present invention relates to a metal material and a manufacturing method thereof, in particular to a 100-kg cold-rolled low-alloy annealed dual-phase steel and a manufacturing method thereof.
背景技术Background technique
近年来，随着全球能源危机和环境问题的加剧，节能和安全成为了汽车制造业的主要发展方向，其中降低车重便是节能和减少排放措施之一。在实际应用过程中，由于高强度双相钢具有良好的机械性能和使用性能，其可以有效适用于车辆结构件的生产制造。In recent years, with the intensification of the global energy crisis and environmental problems, energy conservation and safety have become the main development directions of the automobile manufacturing industry. Among them, reducing vehicle weight is one of the measures to save energy and reduce emissions. In actual application, high-strength dual-phase steel has good mechanical properties and usability, and can be effectively used in the production and manufacturing of vehicle structural parts.
当前，随着超高强钢的发展以及目前市场的变化，市场和用户普遍期望高强钢具有经济型以及更优的性能。目前980MPa级的低合金钢仍是主流应用钢，占整个低合金钢总量的20％比例，其广泛地应用于各种类型的结构件、安全件。而随着汽车行业减重节能的趋势不断发展，国内外特别是国内钢厂水平的迅速进步，未来双相钢的发展，必然会是以低成本和高性能综合为主。Currently, with the development of ultra-high-strength steel and current market changes, the market and users generally expect high-strength steel to be economical and have better performance. At present, 980MPa grade low alloy steel is still the mainstream applied steel, accounting for 20% of the total low alloy steel. It is widely used in various types of structural parts and safety parts. With the continuous development of the trend of weight reduction and energy saving in the automobile industry, and the rapid progress of domestic and foreign steel mills in particular, the future development of dual-phase steel will inevitably be based on a combination of low cost and high performance.
在当前现有技术中，针对980MPa级的双相钢，当前研究人员已经进行了大量的研究，并已经取得了一定的研究成果。In the current existing technology, current researchers have conducted a lot of research on 980MPa grade dual-phase steel and have achieved certain research results.
例如：公开号为CN109280854A，公开日为2019年1月29日，名称为“980MPa级低碳冷轧双相钢及其制备方法”的中国专利文献，公开了一种980MPa级低碳冷轧双相钢。该技术方案所要解决的是现有980MPa级冷轧双相钢生产成本高、生产难度大的技术问题，其化学成分质量百分比为：C：0.05～0.10％，Si：0.30～0.70％，Mn：2.00～2.50％，Cr：0.40～0.80％，Al：0.01～0.06％，在转炉中控制铁水V含量，然后经热轧、酸轧、退火工艺得到980MPa级低碳冷轧双相钢。采用该技术方案所制备的双相钢具有优良的力学性能和成形性能优良，其成本优势明显。但是，该技术方案在钢材的设计中采用了贵合金Cr，同时含有较高含量的Mn，其不仅会导致合金成本升高，也会造成严重的带状组织，从而造成力学性能的不均匀性。 For example: the publication number is CN109280854A, the publication date is January 29, 2019, and the Chinese patent document titled "980MPa grade low carbon cold-rolled dual-phase steel and its preparation method" discloses a 980MPa grade low carbon cold-rolled dual-phase steel. Phase steel. This technical solution aims to solve the existing technical problems of high production cost and difficulty in production of 980MPa grade cold-rolled dual-phase steel. Its chemical composition mass percentage is: C: 0.05~0.10%, Si: 0.30~0.70%, Mn: 2.00~2.50%, Cr: 0.40~0.80%, Al: 0.01~0.06%, control the V content of the molten iron in the converter, and then undergo hot rolling, acid rolling, and annealing processes to obtain 980MPa grade low-carbon cold-rolled dual-phase steel. The dual-phase steel prepared using this technical solution has excellent mechanical properties and excellent formability, and its cost advantage is obvious. However, this technical solution uses precious alloy Cr in the design of the steel and also contains a high content of Mn, which will not only increase the cost of the alloy, but also cause severe banding structures, resulting in inhomogeneity of mechanical properties. .
又例如：公开号为CN111455285A，公开日为2020年7月28日，名称为“一种低成本且易生产的抗拉强度980MPa级冷轧双相钢及其生产方法”的中国专利文献，公开了一种抗拉强度980MPa级冷轧双相钢及其生产方法，其化学成分为：C 0.080～0.095％、Si 0.4～0.6％、Mn 2.1～2.3％、Als 0.06～0.08％、Cr 0.2～0.4％、Nb 0.03～0.05％、Ti 0.01～0.02％、Ca 0.0015～0.0040％、P≤0.012％、S≤0.005％、N≤0.005％，余量为Fe和不可避免的杂质。Another example: the publication number is CN111455285A, the publication date is July 28, 2020, and the Chinese patent document titled "A low-cost and easy-to-produce cold-rolled dual-phase steel with a tensile strength of 980MPa and its production method" is published. A cold-rolled dual-phase steel with a tensile strength of 980MPa and a production method thereof are disclosed. Its chemical composition is: C 0.080～0.095%, Si 0.4～0.6%, Mn 2.1～2.3%, Als 0.06～0.08%, Cr 0.2～ 0.4%, Nb 0.03～0.05%, Ti 0.01～0.02%, Ca 0.0015～0.0040%, P≤0.012%, S≤0.005%, N≤0.005%, the balance is Fe and inevitable impurities.
再例如：公开号为CN107043888A，公开日为2017年8月15日，名称为“一种冷弯性能优异的980MPa级冷轧双相钢钢板及其制备方法”的中国专利文献，公开了一种980MPa级冷轧双相钢钢板，其化学成分及重量百分比为：C 0.10～0.12％；Si 0.45～0.65％；Mn 2.4～2.6％；Cr 0.35～0.45％；Nb 0.05～0.075％；Ti 0.06～0.10％；Als 0.055～0.075％；P≤0.008％；S≤0.002％；N≤0.003％，余量为Fe和不可避免的杂质。该技术方案所制备的双相钢钢板虽然具有优异的力学性能，但其钢中设计添加的Cr、Nb、Ti元素的含量较高。Another example: the publication number is CN107043888A, the publication date is August 15, 2017, and the Chinese patent document titled "A 980MPa grade cold-rolled dual-phase steel plate with excellent cold bending performance and its preparation method" discloses a The chemical composition and weight percentage of 980MPa grade cold-rolled dual-phase steel plate are: C 0.10~0.12%; Si 0.45~0.65%; Mn 2.4~2.6%; Cr 0.35~0.45%; Nb 0.05~0.075%; Ti 0.06~ 0.10%; Als 0.055～0.075%; P≤0.008%; S≤0.002%; N≤0.003%, the balance is Fe and inevitable impurities. Although the dual-phase steel plate prepared by this technical solution has excellent mechanical properties, the content of Cr, Nb, and Ti elements designed to be added to the steel is relatively high.
由此可见，现有设计的1000MPa双相钢专利技术，有的虽然涉及较好的成型性能，但这些技术方案要么采用了高C含量和高Si含量，要么含有较多的Cr、Nb、Ti等合金含量，其不仅不利于钢的焊接性、表面质量和磷化性能，同时还会导致成本升高。此外，有些高Si含量的钢材虽然具有很高的扩孔率且弯曲性能较好，但屈强比高，冲压性能下降。It can be seen that although some of the existing patented technologies for designing 1000MPa dual-phase steel involve better formability, these technical solutions either use high C content and high Si content, or contain more Cr, Nb, and Ti. The alloy content is not only detrimental to the weldability, surface quality and phosphating performance of the steel, but also leads to increased costs. In addition, although some steels with high Si content have high hole expansion rates and good bending properties, their yield-to-strength ratios are high and their stamping properties are reduced.
因此，为了满足当前市场需求，本发明期望开发出一种兼具经济性以及优异力学性能的100公斤级冷轧低合金退火双相钢。Therefore, in order to meet the current market demand, the present invention hopes to develop a 100-kg cold-rolled low-alloy annealed dual-phase steel that is both economical and has excellent mechanical properties.
发明内容Contents of the invention
本发明的目的之一在于提供一种100公斤级冷轧低合金退火双相钢，该100公斤级冷轧低合金退火双相钢兼具经济性以及优异力学性能，其在不添加Mo、Cr元素的前提下，仍然具有高强度以及优异的延伸率和弯曲性能，其屈服强度≥550MPa；其抗拉强度≥1000MPa；A50标距断裂延伸率≥12％；90度弯曲性能R/t≤1.0，有着十分良好的推广前景和应用价值。本发明中，100公斤级是指钢的抗拉强度≥980MPa，1000MPa级是指钢的抗拉强度≥1000MPa。One of the purposes of the present invention is to provide a 100 kg-grade cold-rolled low-alloy annealed dual-phase steel. The 100-kg grade cold-rolled low-alloy annealed dual-phase steel has both economy and excellent mechanical properties. It does not add Mo or Cr. Under the premise of eliminating elements, it still has high strength and excellent elongation and bending properties. Its yield strength is ≥550MPa; its tensile strength is ≥1000MPa; A 50 gauge fracture elongation is ≥12%; 90-degree bending performance R/t≤ 1.0, has very good promotion prospects and application value. In the present invention, the 100 kg grade refers to the tensile strength of the steel ≥980MPa, and the 1000MPa grade refers to the tensile strength of the steel ≥1000MPa.
为了实现上述目的，本发明提供了一种100公斤级冷轧低合金退火双相钢，其含有Fe及不可避免的杂质元素，其还含有质量百分含量如下的下述各化学 元素：In order to achieve the above object, the present invention provides a 100 kg cold-rolled low-alloy annealed dual-phase steel, which contains Fe and inevitable impurity elements, and also contains the following chemicals in mass percentages: element:
0.1％＜C≤0.13％，Si：0.5％～0.8％，Mn：1.6％～1.8％，Al：0.01％～0.03％，Nb：0.01～0.03％，Ti：0.01～0.03％，B：0.0020～0.0030％；0.1%＜C≤0.13%, Si: 0.5%～0.8%, Mn: 1.6%～1.8%, Al: 0.01%～0.03%, Nb: 0.01～0.03%, Ti: 0.01～0.03%, B: 0.0020～ 0.0030%;
其化学元素不含有Mo和Cr；Its chemical elements do not contain Mo and Cr;
所述100公斤级冷轧低合金退火双相钢的微观组织为马氏体+铁素体。The microstructure of the 100-kg cold-rolled low-alloy annealed dual-phase steel is martensite + ferrite.
进一步地，在本发明所述的100公斤级冷轧低合金退火双相钢中，其各化学元素质量百分含量为：Further, in the 100-kg cold-rolled low-alloy annealed dual-phase steel according to the present invention, the mass percentage content of each chemical element is:
0.1％＜C≤0.13％，Si：0.5％～0.8％，Mn：1.6％～1.8％，Al：0.01％～0.03％，Nb：0.01～0.03％，Ti：0.01～0.03％，B：0.0020～0.0030％，余量为Fe和其他不可避免的杂质。0.1%＜C≤0.13%, Si: 0.5%～0.8%, Mn: 1.6%～1.8%, Al: 0.01%～0.03%, Nb: 0.01～0.03%, Ti: 0.01～0.03%, B: 0.0020～ 0.0030%, the balance is Fe and other inevitable impurities.
在本发明中，发明人采用的是以C-Si-Mn为主的成分体系，以保证所获得的冷轧低合金退火双相钢可以达到1000MPa级强度。该双相钢在化学成分设计中，不添加Mo、Cr等贵重合金元素，其可以有效保证经济型；此外，本发明在化学成分设计时还添加并利用了微量的高淬透性元素B，以起到进一步降低Mn含量的效果；另外，钢中还添加有微量的Nb、Ti，以达到抑制奥氏体晶粒长大的效果，进而有效细化晶粒。In the present invention, the inventor uses a composition system mainly composed of C-Si-Mn to ensure that the obtained cold-rolled low-alloy annealed dual-phase steel can reach 1000MPa strength. In the chemical composition design of this dual-phase steel, no precious alloy elements such as Mo and Cr are added, which can effectively ensure economy; in addition, the present invention also adds and utilizes a trace amount of high-hardenability element B in the chemical composition design. To further reduce the Mn content; in addition, trace amounts of Nb and Ti are added to the steel to inhibit the growth of austenite grains and effectively refine the grains.
本发明所述的100公斤级冷轧低合金退火双相钢中，各化学元素的设计原理具体如下所述：In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the design principles of each chemical element are specifically as follows:
C：在本发明所述的100公斤级冷轧低合金退火双相钢中，添加C元素可以提高钢材的强度，并提高马氏体的硬度。若钢中C的质量百分含量低于0.1％，则钢板的强度会受到影响，并且不利于奥氏体的形成量和稳定性；而当钢中C元素的质量百分含量高于0.13％，则会造成马氏体硬度过高，晶粒尺寸粗大，不利于钢板的成型性能，同时碳当量过高，不利于焊接使用。由此，为了确保钢材的性能，在本发明所述的100公斤级冷轧低合金退火双相钢中，具体将C元素的质量百分含量控制为0.1％＜C≤0.13％，例如C元素的质量百分含量可以为0.101％、0.105％、0.11％、0.115％、0.12％、0.125％、0.13％或在前述任意两个值的范围内。C: In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, adding C element can improve the strength of the steel and increase the hardness of martensite. If the mass percentage of C in the steel is less than 0.1%, the strength of the steel plate will be affected and is not conducive to the formation and stability of austenite; and when the mass percentage of the C element in the steel is higher than 0.13% , it will cause the martensite hardness to be too high and the grain size to be coarse, which is not conducive to the formability of the steel plate. At the same time, the carbon equivalent is too high, which is not conducive to welding. Therefore, in order to ensure the performance of the steel, in the 100 kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the mass percentage of the C element is specifically controlled to 0.1% <C ≤ 0.13%, for example, the C element The mass percentage can be 0.101%, 0.105%, 0.11%, 0.115%, 0.12%, 0.125%, 0.13% or within the range of any two of the aforementioned values.
Si：在本发明所述的100公斤级冷轧低合金退火双相钢中，钢中添加Si元素可以提高钢材的淬透性，并且钢中固溶的Si可以影响位错的交互作用，从而增加加工硬化率，其可以适当提高双相钢的延伸率，并有益于获得较好的 成型性。但需要注意的是，钢中Si元素含量也不宜过高，当钢中Si元素的质量百分含量过高时，会不利于钢板表面质量的控制。因此，为了发挥Si元素的有益效果，在本发明所述的100公斤级冷轧低合金退火双相钢中，将Si元素的质量百分含量控制在0.5％～0.8％之间，例如Si元素的质量百分含量可以为0.5％、0.55％、0.6％、0.65％、0.7％、0.75％、0.8％或在前述任意两个值的范围内。Si: In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, adding Si element to the steel can improve the hardenability of the steel, and the solid solution Si in the steel can affect the interaction of dislocations, thereby Increasing the work hardening rate can appropriately increase the elongation of dual-phase steel and is beneficial to obtaining better Formability. However, it should be noted that the Si element content in steel should not be too high. When the mass percentage of Si element in steel is too high, it will be detrimental to the control of the surface quality of the steel plate. Therefore, in order to exert the beneficial effects of Si element, in the 100 kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the mass percentage content of Si element is controlled between 0.5% and 0.8%, for example, Si element The mass percentage can be 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8% or within the range of any two of the aforementioned values.
Mn：在本发明所述的100公斤级冷轧低合金退火双相钢中，添加Mn元素不仅有利于提高钢材的淬透性，其还可以有效提高钢板的强度。当钢中Mn元素的质量百分含量低于1.6％时，则钢板的强度不足；而当钢中Mn元素的质量百分含量高于1.8％时，则钢板的强度过高，会使得其成型性能下降。因此，考虑到Mn元素的有益效果，在本发明所述的100公斤级冷轧低合金退火双相钢中，将Mn元素的质量百分含量控制在1.6％～1.8％之间，例如Mn元素的质量百分含量可以为1.6％、1.63％、1.65％、1.68％、1.7％、1.73％、1.75％、1.78％、1.8％或在前述任意两个值的范围内。Mn: In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, adding Mn element is not only beneficial to improving the hardenability of the steel, but can also effectively improve the strength of the steel plate. When the mass percentage of the Mn element in the steel is less than 1.6%, the strength of the steel plate is insufficient; and when the mass percentage of the Mn element in the steel is higher than 1.8%, the strength of the steel plate is too high, which will cause it to form Performance degrades. Therefore, taking into account the beneficial effects of Mn element, in the 100 kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the mass percentage of Mn element is controlled between 1.6% and 1.8%, for example, Mn element The mass percentage may be 1.6%, 1.63%, 1.65%, 1.68%, 1.7%, 1.73%, 1.75%, 1.78%, 1.8% or within the range of any two of the aforementioned values.
Al：在本发明所述的100公斤级冷轧低合金退火双相钢中，Al元素的添加可以起到脱氧作用和细化晶粒的作用。另一方面，钢中Al元素的含量越低，则越有利于冶炼的可浇性。为此，为了发挥Al元素的有益效果，在本发明中，将Al元素的质量百分含量控制在0.01％～0.03％之间，例如Al元素的质量百分含量可以为0.01％、0.015％、0.02％、0.025％、0.03％或在前述任意两个值的范围内。Al: In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the addition of Al element can play a deoxidizing effect and refine the grains. On the other hand, the lower the content of Al element in steel, the more beneficial it is to the castability of smelting. For this reason, in order to exert the beneficial effects of Al element, in the present invention, the mass percentage content of Al element is controlled between 0.01% and 0.03%. For example, the mass percentage content of Al element can be 0.01%, 0.015%, 0.02%, 0.025%, 0.03% or within the range of any two of the aforementioned values.
Nb：在本发明所述的100公斤级冷轧低合金退火双相钢中，Nb元素是细化晶粒的重要元素，在微合金钢中加入少量的强碳化物形成元素Nb后，在控制轧制过程中，可以应变诱导析出相通过质点钉扎和亚晶界的作用而相当显著的降低变形奥氏体的再结晶温度，提供形核质点，其对细化晶粒作用明显；此外，在连续退火奥氏体化过程中，均热未溶的碳、氮化物质点将通过质点钉扎晶界机制而阻止均热奥氏体晶粒的粗化，从而有效细化晶粒。基于此，为了发挥Nb元素的有益效果，在本发明所述的100公斤级冷轧低合金退火双相钢中，具体将Nb元素的质量百分含量控制在0.01～0.03％之间，例如Nb元素的质量百分含量可以为0.01％、0.015％、0.02％、0.025％、0.03％或在前述任意两个值的范围内。 Nb: In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the Nb element is an important element for refining grains. After adding a small amount of strong carbide-forming element Nb to the micro-alloy steel, the During the rolling process, the strain-induced precipitate phase can significantly reduce the recrystallization temperature of deformed austenite through particle pinning and sub-grain boundaries, providing nucleation particles, which has an obvious effect on refining grains; in addition, During the continuous annealing austenitization process, the undissolved carbon and nitride material points in the soaking will prevent the coarsening of the soaking austenite grains through the particle pinning grain boundary mechanism, thereby effectively refining the grains. Based on this, in order to exert the beneficial effects of Nb element, in the 100 kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the mass percentage of Nb element is specifically controlled between 0.01 and 0.03%, for example, Nb The mass percentage of the element can be 0.01%, 0.015%, 0.02%, 0.025%, 0.03% or within the range of any two of the aforementioned values.
当然，在一些优选的实施方式中，为了实现更优的实施效果，可以进一步优选地将Nb元素的质量百分含量控制在0.015～0.025％之间。Of course, in some preferred embodiments, in order to achieve better implementation effects, the mass percentage of the Nb element can be further preferably controlled between 0.015% and 0.025%.
Ti：在本发明所述的100公斤级冷轧低合金退火双相钢中，添加的强碳化物形成元素Ti在高温下也显示出一种强烈的抑制奥氏体晶粒长大的效果，同时Ti元素的添加也有助于细化晶粒。因此，为发挥Ti元素的有益效果，在本发明中，具体将Ti元素的质量百分含量控制在0.01～0.03％之间，例如Ti元素的质量百分含量可以为0.01％、0.015％、0.02％、0.025％、0.03％或在前述任意两个值的范围内。Ti: In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the added strong carbide-forming element Ti also shows a strong effect of inhibiting austenite grain growth at high temperatures. At the same time, the addition of Ti element also helps to refine the grains. Therefore, in order to exert the beneficial effects of the Ti element, in the present invention, the mass percentage content of the Ti element is specifically controlled between 0.01% and 0.03%. For example, the mass percentage content of the Ti element can be 0.01%, 0.015%, and 0.02 %, 0.025%, 0.03% or within the range of any two of the aforementioned values.
当然，在一些优选的实施方式中，为了实现更优的实施效果，可以进一步优选地将Ti元素的质量百分含量控制在0.015～0.025％之间。Of course, in some preferred embodiments, in order to achieve better implementation effects, the mass percentage of the Ti element can be further preferably controlled between 0.015% and 0.025%.
B：在本发明所述的100公斤级冷轧低合金退火双相钢中，添加B元素不仅有利于提高钢的淬透性，其还可以有效提高钢板的强度。当钢中B元素的质量百分含量低于0.0020％时，其同样会引起钢板的强度不足；而当钢中B元素的质量百分含量高于0.0030％时，则同样也会导致钢板的强度过高，并使得其成型性能下降。因此，在本发明所述的100公斤级冷轧低合金退火双相钢中，将B元素的质量百分含量控制在0.0020～0.0030％之间，例如B元素的质量百分含量可以为0.0020％、0.0023％、0.0025％、0.0028％、0.0030％或在前述任意两个值的范围内。B: In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, adding B element is not only beneficial to improving the hardenability of the steel, but can also effectively improve the strength of the steel plate. When the mass percentage of the B element in the steel is less than 0.0020%, it will also cause the strength of the steel plate to be insufficient; and when the mass percentage of the B element in the steel is higher than 0.0030%, it will also cause the strength of the steel plate to be insufficient. Too high, and its molding performance will be reduced. Therefore, in the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the mass percentage content of the B element is controlled between 0.0020 and 0.0030%. For example, the mass percentage content of the B element can be 0.0020%. , 0.0023%, 0.0025%, 0.0028%, 0.0030% or within the range of any two of the aforementioned values.
在上述成分设计中，本发明所设计的这种双相钢中并未添加Mo、Cr等贵重合金元素，其具有十分优异的经济性。同时，为了保证双相钢在40-100℃/s正常连续退火气体冷却速度下可以获得1000MPa级抗拉强度，其化学成分设计中需要保证C、Mn、B的合金添加含量，以提供足够的淬透性。然而，该双相钢中的C、Mn、B合金元素的含量也需要有上限控制，以保证优良的焊接性能及成型性能，并避免强度超出上限。In the above-mentioned composition design, the dual-phase steel designed by the present invention does not add precious alloy elements such as Mo and Cr, and it has very excellent economic efficiency. At the same time, in order to ensure that dual-phase steel can obtain 1000MPa tensile strength under normal continuous annealing gas cooling rate of 40-100℃/s, its chemical composition design needs to ensure the alloy addition content of C, Mn, and B to provide sufficient Hardenability. However, the content of C, Mn, and B alloy elements in this dual-phase steel also needs to be controlled at an upper limit to ensure excellent welding performance and formability, and to avoid the strength exceeding the upper limit.
进一步地，在本发明所述的100公斤级冷轧低合金退火双相钢中，在不可避免的杂质中，P≤0.012％，S≤0.0025％，N≤0.005％。Further, in the 100-kg cold-rolled low-alloy annealed dual-phase steel according to the present invention, among the inevitable impurities, P≤0.012%, S≤0.0025%, and N≤0.005%.
在本发明所述的100公斤级冷轧低合金退火双相钢中，P元素、S元素和N元素均为钢中的杂质元素，在钢中P、N和S元素含量越低，实施效果越好。具体来说，S元素所配合形成的MnS会严重影响钢材的成形性能，而N元素则容易导致板坯表面产生裂纹或气泡。因此，在技术条件允许情况下，为了获 得性能更好且质量更优的钢材，应尽可能降低钢中杂质元素的含量，并具体控制钢中P、S、N元素满足：P≤0.012％，S≤0.0025％，N≤0.005％。在一些实施方案中，在本发明所述的100公斤级冷轧低合金退火双相钢中，P元素的质量百分含量为0.001～0.012％，和/或S元素的质量百分含量为0.001～0.0025％，和/或N元素的质量百分含量为0.001～0.005％。In the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, P element, S element and N element are all impurity elements in the steel. The lower the content of P, N and S elements in the steel, the better the implementation effect. The better. Specifically, the MnS formed by the S element will seriously affect the formability of the steel, while the N element can easily cause cracks or bubbles on the surface of the slab. Therefore, when technical conditions permit, in order to obtain To obtain steel with better performance and better quality, the content of impurity elements in the steel should be reduced as much as possible, and the P, S, and N elements in the steel should be specifically controlled to meet: P ≤ 0.012%, S ≤ 0.0025%, N ≤ 0.005%. In some embodiments, in the 100-kilogram cold-rolled low-alloy annealed dual-phase steel of the present invention, the mass percentage of P element is 0.001 to 0.012%, and/or the mass percentage of S element is 0.001 ~0.0025%, and/or the mass percentage of N element is 0.001~0.005%.
进一步地，在本发明所述的100公斤级冷轧低合金退火双相钢中，其各化学元素的质量百分含量满足下述各项的至少其中一项：Further, in the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the mass percentage content of each chemical element satisfies at least one of the following items:
Nb：0.015～0.025％，Nb: 0.015～0.025%,
Ti：0.015～0.025％。Ti: 0.015～0.025%.
进一步地，在本发明所述的100公斤级冷轧低合金退火双相钢中，其中马氏体的体积百分比含量≥60％，例如马氏体的体积百分比含量可以为60％、65％、70％、75％、80％、85％、90％或在前述任意两个值的范围内。Further, in the 100 kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the volume percentage content of martensite is ≥ 60%. For example, the volume percentage content of martensite can be 60%, 65%, 70%, 75%, 80%, 85%, 90% or within the range of any two of the aforementioned values.
进一步地，在本发明所述的100公斤级冷轧低合金退火双相钢中，其淬透性因子YQ满足：2.0≤YQ≤2.4，其中YQ＝Mn+200×B，式中的各化学元素代入质量百分号前面的数值。在一些实施方案中，淬透性因子YQ为2.0、2.1、2.2、2.3、2.4或在前述任意两个值的范围内。Further, in the 100 kg cold-rolled low-alloy annealed dual-phase steel according to the present invention, its hardenability factor Y Q satisfies: 2.0≤Y Q ≤2.4, where Y Q =Mn+200×B, in the formula Substitute the value before the mass percent sign for each chemical element. In some embodiments, the hardenability factor YQ is 2.0, 2.1, 2.2, 2.3, 2.4, or within the range of any two of the foregoing values.
在本发明所设计的这种100公斤级冷轧低合金退火双相钢中，B元素与Mn元素的复合作用能够使钢材达到较好的强度效果。为使得钢材最终的强度达到要求，在本发明在控制单一化学元素质量百分含量的同时，还可以进一步控制2.0≤YQ≤2.4，其中YQ＝Mn+200×B。In the 100-kg cold-rolled low-alloy annealed dual-phase steel designed by the present invention, the composite effect of B element and Mn element can enable the steel to achieve better strength effects. In order to make the final strength of the steel meet the requirements, while controlling the mass percentage of a single chemical element, the present invention can further control 2.0≤Y Q ≤2.4, where Y Q =Mn+200×B.
但需要注意的是，在合金设计中，Mn含量是影响整体成本的最大当量，故而本发明利用Mn-B的综合淬透性，通过添加适量B，可进一步降低Mn的合金设计量，从而有利于减低成本，同时更有利于现场生产的可制造性提升。However, it should be noted that in alloy design, the Mn content is the largest equivalent that affects the overall cost. Therefore, the present invention utilizes the comprehensive hardenability of Mn-B and adds an appropriate amount of B to further reduce the alloy design amount of Mn, thereby having It is conducive to cost reduction and is more conducive to improving the manufacturability of on-site production.
进一步地，在本发明所述的100公斤级冷轧低合金退火双相钢中，其中马氏体和铁素体的粒径均不大于5微米。例如，马氏体的粒径可以为3.5微米、3.8微米、4微米、4.2微米、4.5微米、4.8微米、5微米或在前述任意两个值的范围内，铁素体的粒径可以为3.5微米、3.8微米、4微米、4.2微米、4.5微米、4.8微米、5微米或在前述任意两个值的范围内。Further, in the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention, the particle size of both martensite and ferrite is not greater than 5 microns. For example, the particle size of martensite can be 3.5 microns, 3.8 microns, 4 microns, 4.2 microns, 4.5 microns, 4.8 microns, 5 microns or within the range of any two of the aforementioned values, and the particle size of ferrite can be 3.5 micron, 3.8 micron, 4 micron, 4.2 micron, 4.5 micron, 4.8 micron, 5 micron or within the range of any two of the aforementioned values.
进一步地，在本发明所述的100公斤级冷轧低合金退火双相钢中，其中马氏体和铁素体的显微硬度差ΔHV≤150。在一些实施方案中，马氏体和铁素体 的显微硬度差ΔHV为90、100、110、120、130、140、150或在前述任意两个值的范围内。Further, in the 100-kg cold-rolled low-alloy annealed dual-phase steel according to the present invention, the microhardness difference ΔHV of martensite and ferrite is ≤150. In some embodiments, martensite and ferrite The microhardness difference ΔHV is 90, 100, 110, 120, 130, 140, 150 or within the range of any two of the aforementioned values.
进一步地，在本发明所述的100公斤级冷轧低合金退火双相钢中，其屈服强度≥550MPa，抗拉强度≥1000MPa，A50标距断裂延伸率≥12％，90度弯曲性能R/t≤1.0。在一些实施方案中，本发明所述的100公斤级冷轧低合金退火双相钢的屈服强度为550MPa、600MPa、650MPa、700MPa或在前述任意两个值的范围内。在一些实施方案中，本发明所述的100公斤级冷轧低合金退火双相钢的抗拉强度为1000MPa、1020MPa、1040MPa、1060MPa、1080MPa、1100MPa或在前述任意两个值的范围内。在一些实施方案中，本发明所述的100公斤级冷轧低合金退火双相钢的A50标距断裂延伸率为12％、13％、14％、15％、16％、17％或在前述任意两个值的范围内。在一些实施方案中，本发明所述的100公斤级冷轧低合金退火双相钢的90度弯曲性能R/t为0.5、0.6、0.7、0.8、0.9、1.0或在前述任意两个值的范围内。Further, in the 100-kg cold-rolled low-alloy annealed dual-phase steel according to the present invention, its yield strength is ≥550MPa, tensile strength is ≥1000MPa, A 50 gauge fracture elongation is ≥12%, and 90-degree bending performance is R /t≤1.0. In some embodiments, the yield strength of the 100 kg cold-rolled low-alloy annealed dual-phase steel of the present invention is 550MPa, 600MPa, 650MPa, 700MPa or within the range of any two of the aforementioned values. In some embodiments, the tensile strength of the 100 kg grade cold-rolled low-alloy annealed dual-phase steel of the present invention is 1000MPa, 1020MPa, 1040MPa, 1060MPa, 1080MPa, 1100MPa or within the range of any two of the aforementioned values. In some embodiments, the 100 kg grade cold rolled low alloy annealed dual phase steel of the present invention has an A 50 gauge elongation at break of 12%, 13%, 14%, 15%, 16%, 17% or at Within the range of any two of the aforementioned values. In some embodiments, the 90-degree bending property R/t of the 100-kg cold-rolled low-alloy annealed dual-phase steel of the present invention is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, or any two of the aforementioned values. within the range.
相应地，本发明的又一目的在于提供上述的100公斤级冷轧低合金退火双相钢的制造方法，该制造方法实施方便且简单，采用该制造方法制得的100公斤级冷轧低合金退火双相钢具有高强度以及优良的延伸率和弯曲性能，其屈服强度≥550MPa，抗拉强度≥1000MPa，A50标距断裂延伸率≥12％，90度弯曲性能R/t≤1.0。Accordingly, another object of the present invention is to provide a method for manufacturing the above-mentioned 100 kg-grade cold-rolled low-alloy annealed dual-phase steel. The manufacturing method is convenient and simple to implement. The 100-kg grade cold-rolled low alloy produced by the manufacturing method Annealed dual-phase steel has high strength and excellent elongation and bending properties. Its yield strength is ≥550MPa, tensile strength is ≥1000MPa, A 50 gauge fracture elongation is ≥12%, and 90-degree bending performance R/t≤1.0.
为了实现上述目的，本发明提出了上述的100公斤级冷轧低合金退火双相钢的制造方法，其包括步骤：In order to achieve the above object, the present invention proposes a method for manufacturing the above-mentioned 100 kg cold-rolled low-alloy annealed dual-phase steel, which includes the steps:
(1)冶炼和铸造；(1) Smelting and casting;
(2)热轧：将连铸坯先加热至1160～1190℃，保温150min以上、例如150～250min，然后在850～890℃进行热轧终轧，轧后以30～80℃/s的速度快速冷却；接着进行卷取，卷取温度为500～540℃，卷取后空冷；(2) Hot rolling: first heat the continuous casting billet to 1160~1190℃, keep it warm for more than 150min, such as 150~250min, and then perform hot rolling and final rolling at 850~890℃. After rolling, the speed is 30~80℃/s. Rapid cooling; then coiling, the coiling temperature is 500~540℃, and air cooling after coiling;
(3)冷轧；(3) Cold rolling;
(4)退火：退火均热温度为825～855℃，退火时间为40～200s，然后以3～5℃/s的速度冷却到快冷开始温度，然后以40～100℃/s的速度快速冷却，其中快冷开始温度为735～760℃，快冷结束温度为265～290℃；(4) Annealing: The annealing soaking temperature is 825~855℃, the annealing time is 40~200s, and then cooled to the rapid cooling starting temperature at a speed of 3~5℃/s, and then rapidly cooled at a speed of 40~100℃/s Cooling, where the starting temperature of rapid cooling is 735~760℃, and the ending temperature of fast cooling is 265~290℃;
(5)回火；(5) Tempering;
(6)平整。 (6) Smooth.
进一步地，在本发明所述的制造方法中，在步骤(4)中，退火均热温度为830～840℃。Further, in the manufacturing method of the present invention, in step (4), the annealing soaking temperature is 830 to 840°C.
在本发明所设计的这种技术方案中，在某些优选的实施方式中，为了获得更优的实施效果，使获得的晶粒尺寸更加细小，获得的钢材的机械性能适中，成型性能更优，可以进一步优选地将退火均热温度控制在830-840℃之间。In the technical solution designed by the present invention, in some preferred embodiments, in order to obtain better implementation effects, the obtained grain size is made smaller, the mechanical properties of the obtained steel are moderate, and the formability is better , the annealing soaking temperature can be further preferably controlled between 830-840°C.
进一步地，在本发明所述的制造方法中，在步骤(3)中，控制冷轧压下率为50～70％。Further, in the manufacturing method of the present invention, in step (3), the cold rolling reduction rate is controlled to 50% to 70%.
进一步地，在本发明所述的制造方法中，在步骤(5)中，控制回火温度为265～290℃，回火时间为100～400s。Further, in the manufacturing method of the present invention, in step (5), the tempering temperature is controlled to be 265-290°C, and the tempering time is controlled to be 100-400 s.
进一步地，在本发明所述的制造方法中，在步骤(6)中，控制平整压下率≤0.3％，例如0.1～0.3％。Further, in the manufacturing method of the present invention, in step (6), the flattening reduction rate is controlled to be ≤0.3%, such as 0.1 to 0.3%.
相较于现有技术，本发明所述的100公斤级冷轧低合金退火双相钢及其制造方法具有如下所述的优点以及有益效果：Compared with the existing technology, the 100-kg cold-rolled low-alloy annealed dual-phase steel and its manufacturing method according to the present invention have the following advantages and beneficial effects:
本发明开发了一种新的100公斤级冷轧低合金退火双相钢，其通过合理的化学成分设计并配合优化的制造工艺，能够在不添加Mo、Cr这些硅合金元素的前提下，得到达到1000MPa级强度的马氏体+铁素体双相组织的钢板；这种细小均匀的马氏体+铁素体双相组织能够进一步保证钢材在延伸率和弯曲性能上表现优良，具有较好成型性。The present invention has developed a new 100-kg cold-rolled low-alloy annealed dual-phase steel. Through reasonable chemical composition design and optimized manufacturing processes, it can be obtained without adding silicon alloy elements such as Mo and Cr. A steel plate with a martensite + ferrite dual-phase structure reaching 1000MPa strength; this fine and uniform martensite + ferrite dual-phase structure can further ensure that the steel has excellent elongation and bending properties, and has better Formability.
由此，采用本发明所设计制备的100公斤级冷轧低合金退火双相钢不仅具有良好经济性，还具有高强度以及优良的延伸率、弯曲性能特性，其屈服强度≥550MPa，抗拉强度≥1000MPa，A50标距断裂延伸率≥12％，90度弯曲性能R/t≤1.0。该100公斤级冷轧低合金退火双相钢生产制备简单，其有着十分良好的推广前景和应用价值，可以有效满足市场和用户的需求。Therefore, the 100-kg cold-rolled low-alloy annealed dual-phase steel designed and prepared by the present invention not only has good economy, but also has high strength and excellent elongation and bending performance characteristics, with a yield strength of ≥550MPa and a tensile strength of ≥550MPa. ≥1000MPa, A 50 gauge breaking elongation ≥12%, 90 degree bending performance R/t≤1.0. The 100-kg cold-rolled low-alloy annealed dual-phase steel is simple to produce and prepare. It has very good promotion prospects and application value and can effectively meet the needs of the market and users.
具体实施方式Detailed ways
下面将结合具体的实施例对本发明所述的100公斤级冷轧低合金退火双相钢及其制造方法做进一步的解释和说明，然而该解释和说明并不对本发明的技术方案构成不当限定。The 100-kg cold-rolled low-alloy annealed dual-phase steel and its manufacturing method according to the present invention will be further explained and described below with reference to specific examples. However, this explanation and description do not unduly limit the technical solution of the present invention.
实施例1-6和对比例1-14Examples 1-6 and Comparative Examples 1-14
表1-1列出了实施例1-6的100公斤级冷轧低合金退火双相钢和对比例 1-14的对比钢材所设计的各化学元素的质量百分配比。Table 1-1 lists the 100 kg cold-rolled low-alloy annealed dual-phase steels of Examples 1-6 and the comparative examples. The mass percentage ratio of each chemical element designed for 1-14 comparative steel.
表1-1.(wt％，余量为Fe和除P、S和N以外其他不可避免的杂质)
Table 1-1. (wt%, the balance is Fe and other unavoidable impurities except P, S and N)
表1-2列出了实施例1-6的100公斤级冷轧低合金退火双相钢和对比例1-14的对比钢材的淬透性因子YQ的值。Table 1-2 lists the values of the hardenability factor Y Q of the 100 kg cold-rolled low-alloy annealed dual-phase steel of Examples 1-6 and the comparative steel of Comparative Examples 1-14.
表1-2.
Table 1-2.
注：在上述表1-2中，YQ＝Mn+200×B，式中的各化学元素代入质量百分号前面的数值。 Note: In the above Table 1-2, Y Q =Mn+200×B, and each chemical element in the formula is substituted into the value before the mass percentage sign.
本发明所述的实施例1-6的100公斤级冷轧低合金退火双相钢和对比例1-14的对比钢材均采用以下步骤制得：The 100 kg cold-rolled low-alloy annealed dual-phase steels of Examples 1-6 of the present invention and the comparative steels of Comparative Examples 1-14 are both prepared by the following steps:
(1)按照表1-1和表1-2所示的化学成分设计进行冶炼和铸造，以制得连铸坯。(1) Smelt and cast according to the chemical composition design shown in Table 1-1 and Table 1-2 to obtain continuous casting billet.
(2)热轧：将连铸坯先加热至1160～1190℃，保温150min以上，然后再在850～890℃进行热轧终轧，轧后以30～80℃/s的速度快速冷却；接着进行卷取，并控制卷取温度为500～540℃，卷取后空冷。(2) Hot rolling: The continuous casting billet is first heated to 1160~1190°C, kept warm for more than 150 minutes, and then hot rolled and finished at 850~890°C. After rolling, it is rapidly cooled at a speed of 30~80°C/s; then Carry out coiling and control the coiling temperature to 500~540℃. After coiling, air cool.
(3)冷轧：对钢卷进行冷轧，并控制冷轧压下率为50～70％。(3) Cold rolling: Cold rolling is performed on the steel coil, and the cold rolling reduction rate is controlled to 50 to 70%.
(4)退火：控制退火均热温度为825～855℃，也可以优选地控制在830～840℃之间，控制退火时间为40～200s，然后以3～5℃/s的速度冷却到快冷开始温度，而后再以40～100℃/s的速度快速冷却，其中快冷开始温度为735～760℃，快冷结束温度为265～290℃。(4) Annealing: Control the annealing soaking temperature to 825-855°C, or preferably between 830-840°C, control the annealing time to 40-200s, and then cool to fast at a speed of 3-5°C/s. The cooling start temperature is then rapidly cooled at a speed of 40 to 100°C/s, where the quick cooling start temperature is 735 to 760°C, and the quick cooling end temperature is 265 to 290°C.
(5)回火：控制回火温度为265～290℃，回火时间为100～400s。(5) Tempering: Control the tempering temperature to 265~290℃ and the tempering time to 100~400s.
(6)平整：控制平整压下率≤0.3％，以获得成品双相钢。(6) Flattening: Control the flattening reduction rate to ≤0.3% to obtain the finished dual-phase steel.
在本发明所设计的这种技术方案中，本发明上述所制备的实施例1-6的100公斤级冷轧低合金退火双相钢的化学成分设计以及相关工艺均满足本发明的设计规范要求。In the technical solution designed by the present invention, the chemical composition design and related processes of the 100 kg cold-rolled low-alloy annealed dual-phase steel prepared in Examples 1-6 of the present invention meet the design specification requirements of the present invention. .
相应地，对比例1-14对比钢材虽然也采用的是表1-1和表1-2的配比方案并结合上述工艺流程进行制备，但为了凸显本发明技术方案的优越性，所设计的对比例1-14的对比钢材在化学成分和/或相关制造工艺中均存在不满足本发明设计要求的参数。Correspondingly, although the comparative steel materials of Comparative Examples 1-14 also adopt the proportioning scheme of Table 1-1 and Table 1-2 and are prepared in combination with the above process flow, in order to highlight the superiority of the technical solution of the present invention, the designed The comparative steel materials of Comparative Examples 1-14 all have parameters in chemical composition and/or related manufacturing processes that do not meet the design requirements of the present invention.
具体来说，对比例1-6的对比钢材在化学成分均存在未能满足本发明设计的要求的参数；而对比例7-14对应的钢种的化学成分虽然满足本发明设计要求，但是相关工艺参数均存在未能满足本发明设计规范的参数。Specifically, the chemical compositions of the comparative steels in Comparative Examples 1-6 all have parameters that fail to meet the design requirements of the present invention; while the chemical compositions of the steel types corresponding to Comparative Examples 7-14 meet the design requirements of the present invention, but the relevant There are parameters in the process parameters that fail to meet the design specifications of the present invention.
表2-1和表2-2列出了实施例1-6的100公斤级冷轧低合金退火双相钢和对比例1-14的对比钢材在上述工艺步骤(1)-(6)中的具体工艺参数。Table 2-1 and Table 2-2 list the 100 kg cold-rolled low alloy annealed dual-phase steel of Examples 1-6 and the comparative steel of Comparative Examples 1-14 in the above process steps (1)-(6). specific process parameters.
表2-1.

table 2-1.

表2-2.

Table 2-2.

需要说明的是，在上述表2-2中，各实施例和对比例的快冷结束温度与回火温度相同，这是因为，在实际工艺操作过程中，快冷操作结束后即进行回火操作。It should be noted that in the above Table 2-2, the quick cooling end temperature and tempering temperature of each embodiment and comparative example are the same. This is because, in the actual process operation, tempering is performed after the quick cooling operation is completed. operate.
相应地，在完成上述制造工艺后，针对所制备的实施例1-6和对比例1-14的成品双相钢，发明人对各实施例和对比例的双相钢分别进行了取样，以获得对应的样品钢板，并针对各实施例和对比例的样品钢板的微观组织采用光学显微镜进行观察和分析，观察发现实施例1-6的100公斤级冷轧低合金退火双相钢和对比例1-14的对比钢板的微观组织均为马氏体+铁素体。Correspondingly, after completing the above-mentioned manufacturing process, the inventor took samples of the finished dual-phase steels of Examples 1-6 and Comparative Examples 1-14, respectively, to Corresponding sample steel plates were obtained, and the microstructure of the sample steel plates of each embodiment and comparative example was observed and analyzed using an optical microscope. It was observed that the 100 kg cold-rolled low alloy annealed dual-phase steel of Examples 1-6 and the comparative example The microstructure of the comparative steel plates 1-14 is all martensite + ferrite.
为此，发明人进一步对各实施例和对比例钢板的微观组织进行分析，以获得实施例1-6和对比例1-14钢板的微观组织中的马氏体相比例、马氏体粒径、铁素体粒径以及马氏体和铁素体的显微硬度差ΔHV的测试结果，相关测试结果具体列于下述表3之中。本发明中，相比例是指采用面积法测量组织中各个相所占的比例；粒径是指各个组织的晶粒大小，以横向和纵向两个方向的平均值为准。相比例、粒径采用光学显微镜进行观察，借助光学显微镜自带的分析软件进行相比例、粒径的测量。显微硬度采用韦氏显微硬度仪进行测量。To this end, the inventor further analyzed the microstructure of the steel plates of each example and comparative example to obtain the martensite phase proportion and martensite particle size in the microstructure of the steel plates of examples 1-6 and comparative examples 1-14. , ferrite particle size and the test results of the microhardness difference ΔHV between martensite and ferrite. The relevant test results are listed in Table 3 below. In the present invention, the phase ratio refers to the proportion of each phase in the structure measured using the area method; the particle size refers to the grain size of each structure, based on the average value in the transverse and longitudinal directions. The phase ratio and particle size were observed using an optical microscope, and the phase ratio and particle size were measured using the analysis software that comes with the optical microscope. Microhardness was measured using a Webster microhardness tester.
表3.

table 3.

从上述表3之中可以看出，在本发明中，实施例1-6所制备的100公斤级冷轧低合金退火双相钢微观组织均为马氏体+铁素体，且其马氏体的体积百分比含量(相比例)在62-82％之间，其马氏体粒径在3.9-4.7μm之间，其铁素体粒径在4.0-4.6μm之间，马氏体和铁素体的显微硬度差ΔHV在95-115之间。It can be seen from the above Table 3 that in the present invention, the microstructure of the 100 kg cold-rolled low-alloy annealed dual-phase steel prepared in Examples 1-6 is martensite + ferrite, and its martensitic The volume percentage content (phase ratio) of the body is between 62-82%, its martensite particle size is between 3.9-4.7μm, its ferrite particle size is between 4.0-4.6μm, martensite and iron The microhardness difference ΔHV of the body is between 95-115.
相应地，完成上述观察以及分析之后，为了验证各实施例和对比例钢材的性能，针对制得的实施例1-6的100公斤级冷轧低合金退火双相钢和对比例1-14的对比钢材进行取样，获得相应样本钢板。并针对所获得实施例1-6和对比例1-14的样品钢板进行力学性能测试，以得到实施例1-6和对比例1-14的钢材的力学性能数据，并将相关试验测试结果列于下述表4中。Accordingly, after completing the above observations and analysis, in order to verify the performance of the steel materials of each embodiment and comparative example, the 100 kilogram grade cold-rolled low-alloy annealed dual-phase steel of Examples 1-6 and the prepared steel of Comparative Examples 1-14 were Sampling of comparative steel materials was carried out to obtain corresponding sample steel plates. And conduct mechanical property tests on the obtained sample steel plates of Examples 1-6 and Comparative Examples 1-14 to obtain the mechanical property data of the steel materials of Examples 1-6 and Comparative Examples 1-14, and list the relevant test results. In Table 4 below.
相关力学性能测试方法如下所述：The relevant mechanical property testing methods are as follows:
拉伸试验测试：采用GB/T228-2010金属材料室温拉伸试验方法进行检测，以检测获得实施例1-6和对比例1-14的钢材的屈服强度、抗拉强度和A50标距断裂延伸率。其中，A50标距断裂延伸率表示：拉伸试样平行长度*宽度为50mm*25mm的断裂延伸率。Tensile test test: Use the GB/T228-2010 room temperature tensile test method for metal materials to detect the yield strength, tensile strength and A 50 gauge fracture of the steel materials obtained in Examples 1-6 and Comparative Examples 1-14. elongation. Among them, the A 50 gauge elongation at break represents: the elongation at break when the parallel length*width of the tensile specimen is 50mm*25mm.
弯曲性能试验：采用GB/T232-2010金属材料弯曲实验方法，以检测获得实施例1-6和对比例1-14的钢材的90度弯曲性能R/t。Bending performance test: GB/T232-2010 metal material bending test method was used to detect the 90-degree bending performance R/t of the steel materials obtained in Examples 1-6 and Comparative Examples 1-14.
表4列出了实施例1-6的100公斤级冷轧低合金退火双相钢和对比例1-14的对比钢材的力学性能测试结果。Table 4 lists the mechanical property test results of the 100 kg cold-rolled low-alloy annealed dual-phase steel of Examples 1-6 and the comparative steel of Comparative Examples 1-14.
表4.

Table 4.

注：公斤力即千克力，是力的一种常用单位，力的国际单位是牛顿；1公斤力指的是1千克的物体所受的重力(即9.8N)，所以1千克力＝9.8牛顿。Note: Kilogram force is kilogram force, which is a common unit of force. The international unit of force is Newton; 1 kilogram force refers to the gravity (i.e. 9.8N) on an object of 1 kilogram, so 1 kilogram force = 9.8 Newtons. .
由表4可知，在本发明中，采用本发明所设计的这种技术方案制备的实施例1-6的100公斤级冷轧低合金退火双相钢具有相当优异的力学性能，其屈服强度在585-655MPa之间，抗拉强度在1002-1054MPa之间，其A50标距断裂延伸率在12.7-15.5％之间，且90度弯曲性能R/t在0.6-1.0之间。各实施例的双相钢在未添加Mo、Cr等贵重合金元素的前提下，获得了大于1000MPa的抗拉强度，其均为100公斤级冷轧低合金退火双相钢，同时具有较好的延伸率和弯曲性能。As can be seen from Table 4, in the present invention, the 100 kg cold-rolled low-alloy annealed dual-phase steel of Examples 1-6 prepared using the technical solution designed by the present invention has quite excellent mechanical properties, and its yield strength is Between 585-655MPa, the tensile strength is between 1002-1054MPa, its A 50 gauge elongation at break is between 12.7-15.5%, and the 90-degree bending performance R/t is between 0.6-1.0. The dual-phase steels in each embodiment achieved a tensile strength greater than 1000MPa without adding precious alloy elements such as Mo and Cr. They are all 100-kg cold-rolled low-alloy annealed dual-phase steels and have good Elongation and bending properties.
相较于实施例1-6的100公斤级冷轧低合金退火双相钢，由于对比例1-14的对比钢材在化学成分设计和/或相关制造工艺中存在为满足本发明要求的参数，因此其综合性能明显较劣。Compared with the 100 kg cold-rolled low-alloy annealed dual-phase steel of Examples 1-6, since the comparative steel of Comparative Examples 1-14 has parameters that meet the requirements of the present invention in the chemical composition design and/or related manufacturing processes, Therefore, its overall performance is obviously inferior.
综上所述可以看出，在本发明中，本发明通过合理的化学成分设计并结合优化工艺，获得了兼具低成本和力学性能优异的双相钢，其获得了大于1000MPa的抗拉强度，同时具有较好的延伸率及弯曲特性。To sum up, it can be seen that in the present invention, through reasonable chemical composition design and combined with optimization process, the present invention obtains dual-phase steel with both low cost and excellent mechanical properties, which obtains a tensile strength greater than 1000MPa. , while having good elongation and bending characteristics.
需要说明的是，本案中各技术特征的组合方式并不限本案权利要求中所记载的组合方式或是具体实施例所记载的组合方式，本案记载的所有技术特征可以以任何方式进行自由组合或结合，除非相互之间产生矛盾。 It should be noted that the combination of each technical feature in this case is not limited to the combination described in the claims of this case or the combination described in the specific embodiments. All the technical features recorded in this case can be freely combined in any way or combination, unless there is a conflict between them.
还需要注意的是，以上所列举的实施例仅为本发明的具体实施例。显然本发明不局限于以上实施例，随之做出的类似变化或变形是本领域技术人员能从本发明公开的内容直接得出或者很容易便联想到的，均应属于本发明的保护范围。 It should also be noted that the embodiments listed above are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and subsequent similar changes or deformations that those skilled in the art can directly derive from the disclosed content of the present invention or can easily associate them should all fall within the protection scope of the present invention. .

Claims (14)

  1. 一种100公斤级冷轧低合金退火双相钢，其含有Fe及不可避免的杂质元素，其特征在于，其还含有质量百分含量如下的下述各化学元素：A 100-kilogram grade cold-rolled low-alloy annealed dual-phase steel contains Fe and inevitable impurity elements. It is characterized in that it also contains the following chemical elements in the following mass percentages:
    0.1％＜C≤0.13％，Si：0.5％～0.8％，Mn：1.6％～1.8％，Al：0.01％～0.03％，Nb：0.01～0.03％，Ti：0.01～0.03％，B：0.0020～0.0030％；0.1%＜C≤0.13%, Si: 0.5%～0.8%, Mn: 1.6%～1.8%, Al: 0.01%～0.03%, Nb: 0.01～0.03%, Ti: 0.01～0.03%, B: 0.0020～ 0.0030%;
    其化学元素不含有Mo和Cr；Its chemical elements do not contain Mo and Cr;
    所述100公斤级冷轧低合金退火双相钢的微观组织为马氏体+铁素体。The microstructure of the 100-kg cold-rolled low-alloy annealed dual-phase steel is martensite + ferrite.
  2. 如权利要求1所述的100公斤级冷轧低合金退火双相钢，其特征在于，其各化学元素质量百分含量为：The 100-kg cold-rolled low-alloy annealed dual-phase steel as claimed in claim 1, characterized in that the mass percentage of each chemical element is:
    0.1％＜C≤0.13％，Si：0.5％～0.8％，Mn：1.6％～1.8％，Al：0.01％～0.03％，Nb：0.01～0.03％，Ti：0.01～0.03％，B：0.0020～0.0030％，余量为Fe和其他不可避免的杂质。0.1%＜C≤0.13%, Si: 0.5%～0.8%, Mn: 1.6%～1.8%, Al: 0.01%～0.03%, Nb: 0.01～0.03%, Ti: 0.01～0.03%, B: 0.0020～ 0.0030%, the balance is Fe and other inevitable impurities.
  3. 如权利要求1或2所述的100公斤级冷轧低合金退火双相钢，其特征在于，在不可避免的杂质中，P≤0.012％，S≤0.0025％，N≤0.005％。The 100-kg cold-rolled low-alloy annealed dual-phase steel according to claim 1 or 2, characterized in that among the inevitable impurities, P≤0.012%, S≤0.0025%, and N≤0.005%.
  4. 如权利要求1或2所述的100公斤级冷轧低合金退火双相钢，其特征在于，其各化学元素的质量百分含量满足下述各项的至少其中一项：The 100-kg cold-rolled low-alloy annealed dual-phase steel as claimed in claim 1 or 2, characterized in that the mass percentage content of each chemical element satisfies at least one of the following items:
    Nb：0.015～0.025％，Nb: 0.015～0.025%,
    Ti：0.015～0.025％。Ti: 0.015～0.025%.
  5. 如权利要求1或2所述的100公斤级冷轧低合金退火双相钢，其特征在于，马氏体的体积百分比含量≥60％。The 100-kg cold-rolled low-alloy annealed dual-phase steel according to claim 1 or 2, characterized in that the volume percentage content of martensite is ≥ 60%.
  6. 如权利要求1或2所述的100公斤级冷轧低合金退火双相钢，其特征在于，淬透性因子YQ满足：2.0≤YQ≤2.4，其中YQ＝Mn+200×B，式中的各化学元素代入质量百分号前面的数值。The 100-kg cold-rolled low-alloy annealed dual-phase steel as claimed in claim 1 or 2, characterized in that the hardenability factor Y Q satisfies: 2.0≤Y Q ≤2.4, where Y Q =Mn+200×B, For each chemical element in the formula, substitute the value before the mass percent sign.
  7. 如权利要求1或2所述的100公斤级冷轧低合金退火双相钢，其特征在于，马氏体和铁素体的粒径均不大于5微米。The 100-kg cold-rolled low-alloy annealed dual-phase steel as claimed in claim 1 or 2, characterized in that the particle size of both martensite and ferrite is not greater than 5 microns.
  8. 如权利要求1或2所述的100公斤级冷轧低合金退火双相钢，其特征在于，马氏体和铁素体的显微硬度差ΔHV≤150。The 100-kg cold-rolled low-alloy annealed dual-phase steel according to claim 1 or 2, characterized in that the microhardness difference ΔHV of martensite and ferrite is less than or equal to 150.
  9. 如权利要求1或2所述的100公斤级冷轧低合金退火双相钢，其特征在于， 其屈服强度≥550MPa，抗拉强度≥1000MPa，A50标距断裂延伸率≥12％，90度弯曲性能R/t≤1.0。The 100 kg cold-rolled low-alloy annealed dual-phase steel as claimed in claim 1 or 2, characterized in that, Its yield strength is ≥550MPa, tensile strength is ≥1000MPa, A 50 gauge fracture elongation is ≥12%, and 90-degree bending performance R/t≤1.0.
  10. 如权利要求1-9中任意一项所述的100公斤级冷轧低合金退火双相钢的制造方法，其特征在于，其包括步骤：The manufacturing method of 100 kg cold-rolled low-alloy annealed dual-phase steel according to any one of claims 1-9, characterized in that it includes the steps:
    (1)冶炼和铸造；(1) Smelting and casting;
    (2)热轧：将连铸坯先加热至1160～1190℃，保温150min以上，然后在850～890℃进行热轧终轧，轧后以30～80℃/s的速度快速冷却；接着进行卷取，卷取温度为500～540℃，卷取后空冷；(2) Hot rolling: The continuous casting billet is first heated to 1160~1190°C, kept warm for more than 150 minutes, and then hot rolled and finished at 850~890°C. After rolling, it is rapidly cooled at a speed of 30~80°C/s; then proceed Coiling, the coiling temperature is 500~540℃, air cooling after coiling;
    (3)冷轧；(3) Cold rolling;
    (4)退火：退火均热温度为825～855℃，退火时间为40～200s，然后以3～5℃/s的速度冷却到快冷开始温度，然后以40～100℃/s的速度快速冷却，其中快冷开始温度为735～760℃，快冷结束温度为265～290℃；(4) Annealing: The annealing soaking temperature is 825~855℃, the annealing time is 40~200s, and then cooled to the rapid cooling starting temperature at a speed of 3~5℃/s, and then rapidly cooled at a speed of 40~100℃/s Cooling, where the starting temperature of rapid cooling is 735~760℃, and the ending temperature of fast cooling is 265~290℃;
    (5)回火；(5) Tempering;
    (6)平整。(6) Smooth.
  11. 如权利要求10所述的制造方法，其特征在于，在步骤(4)中，退火均热温度为830～840℃。The manufacturing method according to claim 10, characterized in that in step (4), the annealing soaking temperature is 830-840°C.
  12. 如权利要求10所述的制造方法，其特征在于，在步骤(3)中，控制冷轧压下率为50～70％。The manufacturing method according to claim 10, characterized in that in step (3), the cold rolling reduction rate is controlled to be 50-70%.
  13. 如权利要求10所述的制造方法，其特征在于，在步骤(5)中，控制回火温度为265～290℃，回火时间为100～400s。The manufacturing method according to claim 10, characterized in that in step (5), the tempering temperature is controlled to be 265-290°C, and the tempering time is controlled to be 100-400 s.
  14. 如权利要求10所述的制造方法，其特征在于，在步骤(6)中，控制平整压下率≤0.3％。 The manufacturing method according to claim 10, characterized in that, in step (6), the flattening reduction rate is controlled to be ≤0.3%.
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