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WO2025077826A1 - Tempered steel plate having yield strength of 1000 mpa and production method therefor - Google Patents

Tempered steel plate having yield strength of 1000 mpa and production method therefor Download PDF

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Publication number
WO2025077826A1
WO2025077826A1 PCT/CN2024/124128 CN2024124128W WO2025077826A1 WO 2025077826 A1 WO2025077826 A1 WO 2025077826A1 CN 2024124128 W CN2024124128 W CN 2024124128W WO 2025077826 A1 WO2025077826 A1 WO 2025077826A1
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Prior art keywords
steel plate
mpa
yield strength
quenched
temperature
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French (fr)
Chinese (zh)
Inventor
唐骜
刘刚
杨阿娜
李自刚
王巍
温东辉
吴祖国
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Baoshan Iron and Steel Co Ltd
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Baoshan Iron and Steel Co Ltd
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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
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • 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
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
    • 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
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • 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
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • 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
    • 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese

Definitions

  • the invention relates to the technical field of quenched and tempered steel plates and their manufacturing, and in particular to a quenched and tempered steel plate with a yield strength of 1000MPa and a production method thereof.
  • Construction machinery is an important part of the equipment industry. With the development of large-scale, high-end and lightweight construction machinery industry, the strength level of steel used in it has been continuously improved, generally rising from the original 500-600MPa to 1000MPa or even 1300MPa. Due to the harsh service environment of high-strength steel used in construction machinery, in addition to high strength, there are strict requirements on the elongation, bending performance, toughness and welding performance of the steel plate.
  • Chinese invention patent CN113430458A discloses an ultra-high strength steel plate with a yield strength of 1040 MPa or above and a manufacturing method thereof, wherein the steel plate comprises: C: 0.07-0.12%, Si: 0.05-0.15%, Mn: 0.70-1.40%, P ⁇ 0.015%, S ⁇ 0.005%, Cu: 0.76-1.40%, Cr: 0.20-0.60%, Ni: 2.0-4.0%, Mo: 0.20-0.80%, Nb ⁇ 0.10%, V: 0.02-0.12%, Ti ⁇ 0.02%, Al ⁇ 0.04%, and the remainder comprises Fe and unavoidable impurity elements. In order to obtain higher strength, Mo: 0.20-0.80% is added to the steel.
  • Chinese invention patent CN114277306A discloses a 1000MPa high-strength steel for engineering machinery and its production method, the chemical composition weight percentage of which is: C: 0.16-0.20%, Si: 0.30-0.50%, Mn: 0.80-1.60%, Cr: 0.20-0.70%, Mo: 0.40-0.70%, W: 0-0.70%, Ni: 0.10-0.50%, Cu: 0-0.40%, Nb: 0.010 ⁇ 0.030%, Ti: 0.010 ⁇ 0.030%, V: 0.010 ⁇ 0.050%, B: 0.0005 ⁇ 0.0030%, Al: 0.02 ⁇ 0.06%, Ca: 0.001 ⁇ 0.004%, N: 0.002 ⁇ 0.005%, P ⁇ 0.020%, S ⁇ 0.0050%, O ⁇ 0.0040%, the rest are Fe and unavoidable impurities; and the above elements must also meet The following relationship is 6 ⁇ (Mo+0.93W+0.52Cr+0.21Mn+0.55)/C ⁇ 10. In order to obtain high strength steel, Mo is added: 0.40-0.7
  • Chinese invention patent CN102560274A discloses a quenched and tempered ultra-high strength steel with a yield strength of 1000MPa, whose chemical composition is (by weight): C: 0.15-0.20%; Si: 0.10-0.40%; Mn: 1.00-1.50%; Cr: 0.30-0.50%; Mo: 0.30-0.50%; Ni: 0.20-0.50%; B: 0.0010-0.0030%; Nb: 0.010-0.030%; V: 0.030-0.050%; Ti: 0.010-0.020%; Alt: 0.030-0.050%; P ⁇ 0.020%; S ⁇ 0.010%, and the rest is Fe and unavoidable impurities, and Mo: 0.30-0.50% is also added to the steel.
  • Chinese invention patent CN116676541A discloses a low-cost 960MPa ultra-high strength steel plate, whose chemical composition mass percentage is: C: 0.18-0.25%, Mn: 1.6-1.8%, Cr: 0.5-0.6%, V: 0.04-0.06%, Ti: 0.01-0.02%, B: 0.001-0.002%, and the rest is Fe and unavoidable impurities. Although the steel does not add Mo element, it mainly uses higher C and Mn content to improve strength.
  • Chinese invention patent CN114318120A discloses an 800MPa high-strength steel for engineering machinery, whose Mo content is 0.10-0.30%, and the yield strength can only be guaranteed to be ⁇ 800MPa.
  • the purpose of the present invention is to provide a quenched and tempered steel plate with a yield strength of 1000MPa and a production method thereof.
  • the quenched and tempered steel plate has a yield strength of ⁇ 1000MPa, a tensile strength of ⁇ 1050MPa, an elongation of >18%, and an impact energy of -40°C of >120J. While achieving ultra-high strength of the steel plate, the cost is low and the comprehensive performance is good.
  • a quenched and tempered steel plate with a yield strength of 1000 MPa wherein the composition by weight percentage is: C: 0.150-0.200%, Si: 0.05-0.30%, Mn: 0.80-1.60%, Cr ⁇ 0.6%, Mo ⁇ 0.20%, V ⁇ 0.060%, N ⁇ 0.0050%, P ⁇ 0.030%, S ⁇ 0.0050%, O ⁇ 0.0040%, and the rest includes Fe and other unavoidable inclusions; and the contents of the above elements must simultaneously satisfy the following relationship:
  • the steel plate further comprises one or more of Nb, Ti, Cu, Ni, B, Al, Ca and RE.
  • the content of the above-mentioned alloys shall meet the following requirements: Nb ⁇ 0.050%, Ti ⁇ 0.050%, Cu ⁇ 0.50%, Ni ⁇ 0.50%, B ⁇ 0.0030%, Al ⁇ 0.06%, Ca ⁇ 0.0040%, and RE ⁇ 0.0050%.
  • the remainder is Fe and other inevitable inclusions.
  • the microstructure of the steel plate of the present invention is tempered martensite + cementite within 50nm + Cr7C3 and VC or (V, Mo)C carbides with a size of 2-10nm.
  • the steel plate of the present invention has a yield strength of ⁇ 1000MPa, a tensile strength of ⁇ 1050MPa, an elongation of >18%, and an impact energy of >120J at -40°C.
  • the yield strength of the steel plate of the present invention is ⁇ 1030 MPa. In some embodiments, the yield strength of the steel plate of the present invention is 1000-1150 MPa.
  • the -40°C impact energy of the steel plate of the present invention is ⁇ 150 J. In some embodiments, the -40°C impact energy of the steel plate of the present invention is 125 to 220 J, preferably 150 to 220 J.
  • Si Si above 0.05% can play a good deoxidation role, and Si exceeding 0.3% is prone to produce red iron scale.
  • the silicon content of the present invention is controlled within the range of 0.05-0.30%.
  • Mn element can improve the hardenability of steel when it is above 0.8%. When the Mn content exceeds 1.6%, it is easy to produce segregation and inclusions such as MnS, which deteriorates the toughness of martensitic high-strength steel. In the present invention, the Mn content is controlled at 0.80-1.60%.
  • Cr can improve the hardenability of steel and is conducive to the formation of full martensite structure during quenching; in addition, it has the effect of resisting tempering softening. Studies have found that when the Cr content is ⁇ 0.60%, Cr carbide Cr 7 C 3 can also be formed during high-temperature tempering, which plays a role of precipitation strengthening or secondary hardening. Therefore, the present invention controls the Cr content to be ⁇ 0.60%. In some embodiments, the present invention controls the Cr content to be 0.60-1.6%.
  • Mo element can improve the hardenability of steel and is conducive to the formation of full martensite structure during quenching; Mo During high temperature tempering, the growth and coarsening of carbides can be suppressed, and the softening of high temperature tempering and weld joints can be resisted; however, too high Mo content will significantly increase the cost. Therefore, the present invention controls the Mo content to be ⁇ 0.20%.
  • V The V element can refine the grains and improve the toughness of the steel. V reacts with C during the tempering process to form carbides, which have a precipitation strengthening effect, resist tempering softening, and improve the strength of the quenched and tempered steel. Therefore, the present invention controls the V content to be ⁇ 0.060%. In some embodiments, the present invention controls the V content to be 0.060-0.130%.
  • Cr, Mo and V are strong carbide forming elements, and their affinity with C is greater than that of Fe with C, so they can inhibit C from combining with Fe to form cementite, and inhibit the coarsening of cementite. Inhibiting the precipitation or coarsening of cementite can increase the C content dissolved in martensite, improve the strength of matrix martensite, and on the other hand, can also inhibit the occurrence of temper brittleness.
  • Mo, Cr, V can react with C to form nano-scale carbides during high-temperature tempering, which plays a role in precipitation strengthening. Therefore, Mo, Cr and V play a role in tempering softening resistance, and improve the strength of steel plate.
  • the precipitation phase control index PCI 3Mo + 0.6Cr + 5V can be defined.
  • PCI ⁇ 1% the precipitation of cementite can be significantly inhibited, and the size of the precipitated cementite (maximum length for non-spherical and diameter for spherical) can be controlled within 50nm to ensure the strength and toughness of the matrix martensite.
  • the size of the precipitated phases of Cr 7 C 3 and VC or (V, Mo) C (maximum length for non-spherical and diameter for spherical) is 2 to 10nm, which can play a significant precipitation strengthening effect and ensure the strength of the steel plate after high temperature tempering.
  • the VC or (V, Mo) C precipitation phase coarsens more seriously, reducing the precipitation strengthening efficiency and significantly reducing toughness; at the same time, too high Mo, Cr and V will also significantly increase the cost of steel. Therefore, the present invention sets the PCI range to: 1.00% ⁇ PCI ⁇ 1.50%.
  • Ca can act as a purifier in the steel smelting process and improve the toughness of the steel; however, when the Ca content exceeds 0.0040%, it is easy to form Ca compounds with larger sizes, which will deteriorate the toughness. Therefore, the present invention controls the Ca content to ⁇ 0.0040%.
  • P, S and O P, S and O as impurity elements affect the plasticity and toughness of steel.
  • the control ranges of the present invention are P ⁇ 0.030%, S ⁇ 0.0050%, and O ⁇ 0.0040%, respectively.
  • the method for producing a quenched and tempered steel plate with a yield strength of 1000 MPa of the present invention comprises the following steps:
  • the heating temperature is 1200-1250°C.
  • the insulation time is more than 1.5h.
  • the rolled steel plate is cooled to 500-700°C at a cooling rate of ⁇ 60°C/s, then coiled and air-cooled to room temperature;
  • Quenching treatment heat the steel plate to 820-950°C, keep the temperature for 5-40min after the core of the steel plate reaches the temperature, and then quickly cool it to room temperature at a cooling rate of ⁇ 20°C/s;
  • the tempering temperature is 450-650°C
  • the core of the steel plate is kept warm after reaching the temperature
  • the holding time is ⁇ 5min
  • the tempering heating temperature in step 5) is 480-650°C.
  • the insulation time of step 5) is 5 to 30 minutes.
  • the present invention adopts low Mo or even no Mo and low C and Mn content, and uses high Cr and V element addition to control 1.00% ⁇ 3Mo+0.6Cr+5V ⁇ 1.50%, inhibits the precipitation of cementite, and The precipitated cementite is controlled within 50nm, and the precipitated Cr 7 C 3 and VC or (V,Mo) C phases are formed, and the high strength of the steel plate is achieved by utilizing its tempering softening resistance and precipitation strengthening effect.
  • the cost is reduced and the adverse effect of adding higher C and Mn element contents on welding performance is avoided when no Mo element is added.
  • the invention controls the temperature and time of quenching and tempering heat treatment on the basis of component design to prevent grain coarsening and control the size of cementite, Cr7C3 and VC or (V, Mo)C carbides.
  • the size of cementite is controlled within 50nm, and Cr7C3 and VC or (V, Mo)C precipitation phases with a size of 2-10nm are formed, thereby obtaining the best precipitation strengthening effect and the best strength-plasticity matching, thereby realizing ultra-high strength at a lower alloy content.
  • FIG1 is a metallographic structure photograph of a steel plate after heat treatment in Example 4 of the present invention.
  • FIG. 2 is a scanning electron microscopic photograph of the steel plate after heat treatment in Example 4 of the present invention.
  • composition of the steel example of the present invention is shown in Table 1, and the manufacturing process parameters of the steel example of the present invention are shown in Table 2.
  • microstructure after heat treatment is tempered martensite.
  • the scanning electron microscopic microstructure photo in Figure 2 shows that there are a large number of dispersed nano-scale precipitates in the microstructure, among which the slightly larger ones are cementite below 50nm, and the very fine ones are Cr 7 C 3 and VC or (V, Mo) C of 2-10nm.
  • the steel of the present invention has ultra-high strength, yield strength ⁇ 1000MPa, tensile strength ⁇ 1050MPa, elongation above 18%, and -40°C impact energy > 120J. This is due to the specific element composition of the embodiment of the present invention, especially the specific combination of Cr, Mo, and V elements, which ensures that the steel plate still maintains high strength under high-temperature tempering conditions; at the same time, the high tempering temperature ensures the high elongation and toughness of the steel plate, achieving a good combination of strength and plasticity.
  • the quenched and tempered steel with a yield strength of 1000 MPa described in the present invention can be used in various fields requiring the use of high-strength steel, especially in the use of steel plates for engineering machinery requiring both high strength and high toughness.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
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  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

A tempered steel plate having a yield strength of 1000 MPa and a production method therefor. The tempered steel plate comprises the following components in percentages by weight: C: 0.15-0.2%, Si: 0.05-0.3%, Mn: 0.80-1.60%, Cr≥0.6%, Mo≤0.2%, V≥0.06%, N≤0.005%, P≤0.030%, S≤0.005%, and O≤0.004%, with the balance being Fe and inevitable impurities, wherein the contents of the elements must satisfy the following relation: 1%≤3Mo+0.6Cr+5V≤1.5%. In the component design of the present invention, a low content of Mo or even no Mo is used, and the content of C and Mn is relatively low; and under these conditions and by means of the tempering resistance and precipitation strengthening effect of Cr and V, high strength of the steel plate is achieved, the cost is low, and the steel plate has good comprehensive performance, with the yield strength thereof being larger than or equal to 1000 MPa, the tensile strength thereof being larger than or equal to 1050 MPa, the elongation thereof being larger than 18%, and the impact energy thereof at -40ºC being larger than 120 J.

Description

一种屈服强度1000MPa级调质钢板及其生产方法A quenched and tempered steel plate with a yield strength of 1000 MPa and a production method thereof 技术领域Technical Field

本发明涉及调质钢板及其制造技术领域，特别涉及一种屈服强度1000MPa级调质钢板及其生产方法。The invention relates to the technical field of quenched and tempered steel plates and their manufacturing, and in particular to a quenched and tempered steel plate with a yield strength of 1000MPa and a production method thereof.

背景技术Background Art

工程机械是设备工业的重要组成部分，随着工程机械行业大型化、高端化和轻量化的发展，其用钢的强度级别不断提高，已普遍从原来的500～600MPa上升至1000MPa甚至1300MPa。由于工程机械用高强钢的服役环境苛刻，在高强度之外，对钢板的延伸率、折弯性能、韧性以及焊接性能有严格要求。Construction machinery is an important part of the equipment industry. With the development of large-scale, high-end and lightweight construction machinery industry, the strength level of steel used in it has been continuously improved, generally rising from the original 500-600MPa to 1000MPa or even 1300MPa. Due to the harsh service environment of high-strength steel used in construction machinery, in addition to high strength, there are strict requirements on the elongation, bending performance, toughness and welding performance of the steel plate.

当前屈服强度1000MPa级调质高强钢在工程机械行业已得到广泛应用。此类钢种为了保证良好的塑性和较高韧性，回火温度较高。为了在高温回火条件下保持屈服大于1000MPa的超高强度，需要加入较高含量的Mo元素以抵抗回火时的软化。At present, quenched and tempered high-strength steel with a yield strength of 1000MPa has been widely used in the engineering machinery industry. In order to ensure good plasticity and high toughness, this type of steel has a high tempering temperature. In order to maintain an ultra-high strength of more than 1000MPa under high-temperature tempering conditions, a high content of Mo element needs to be added to resist softening during tempering.

中国发明专利CN113430458A公开了一种屈服强度1040MPa以上级超高强钢板及其制造方法，钢板包括：C：0.07～0.12％，Si：0.05-0.15％，Mn：0.70-1.40％，P≤0.015％，S≤0.005％，Cu：0.76-1.40％，Cr：0.20-0.60％，Ni：2.0-4.0％，Mo：0.20-0.80％，Nb≤0.10％，V：0.02～0.12％，Ti≤0.02％，Al≤0.04％，余量包括Fe和不可避免的杂质元素。为了获得较高的强度，钢中加入了Mo：0.20～0.80％。Chinese invention patent CN113430458A discloses an ultra-high strength steel plate with a yield strength of 1040 MPa or above and a manufacturing method thereof, wherein the steel plate comprises: C: 0.07-0.12%, Si: 0.05-0.15%, Mn: 0.70-1.40%, P≤0.015%, S≤0.005%, Cu: 0.76-1.40%, Cr: 0.20-0.60%, Ni: 2.0-4.0%, Mo: 0.20-0.80%, Nb≤0.10%, V: 0.02-0.12%, Ti≤0.02%, Al≤0.04%, and the remainder comprises Fe and unavoidable impurity elements. In order to obtain higher strength, Mo: 0.20-0.80% is added to the steel.

中国发明专利CN114277306A公开了一种1000MPa级工程机械用高强钢及其生产方法，其化学成分重量百分比为：C：0.16-0.20％，Si：0.30～0.50％，Mn：0.80-1.60％，Cr：0.20～0.70％，Mo：0.40～0.70％，W：0～0.70％，Ni：0.10～0.50％，Cu：0～0.40％，Nb：0.010～0.030％，Ti：0.010～0.030％，V：0.010～0.050％，B：0.0005～0.0030％，Al：0.02～0.06％，Ca：0.001～0.004％，N：0.002～0.005％，P≤0.020％，S<0.0050％，O≤0.0040％，其余为Fe及不可避免的杂质；且，上述元素同时需满足 如下关系式6≤(Mo+0.93W+0.52Cr+0.21Mn+0.55)/C≤10。为了获得高的强度钢种加入了Mo：0.40～0.70％。Chinese invention patent CN114277306A discloses a 1000MPa high-strength steel for engineering machinery and its production method, the chemical composition weight percentage of which is: C: 0.16-0.20%, Si: 0.30-0.50%, Mn: 0.80-1.60%, Cr: 0.20-0.70%, Mo: 0.40-0.70%, W: 0-0.70%, Ni: 0.10-0.50%, Cu: 0-0.40%, Nb: 0.010～0.030%, Ti: 0.010～0.030%, V: 0.010～0.050%, B: 0.0005～0.0030%, Al: 0.02～0.06%, Ca: 0.001～0.004%, N: 0.002～0.005%, P≤0.020%, S<0.0050%, O≤0.0040%, the rest are Fe and unavoidable impurities; and the above elements must also meet The following relationship is 6≤(Mo+0.93W+0.52Cr+0.21Mn+0.55)/C≤10. In order to obtain high strength steel, Mo is added: 0.40-0.70%.

中国发明专利CN102560274A公开了一种屈服强度1000MPa级调质超高强钢，其化学成分为(重量)：C：0.15～0.20％；Si：0.10～0.40％；Mn：1.00～1.50％；Cr：0.30～0.50％；Mo：0.30～0.50％；Ni：0.20～0.50％；B：0.0010～0.0030％；Nb：0.010～0.030％；V：0.030～0.050％；Ti：0.010～0.020％；Alt：0.030～0.050％；P≤0.020％；S≤0.010％，其余为Fe及不可避免杂质，钢中也添加了Mo：0.30～0.50％。Chinese invention patent CN102560274A discloses a quenched and tempered ultra-high strength steel with a yield strength of 1000MPa, whose chemical composition is (by weight): C: 0.15-0.20%; Si: 0.10-0.40%; Mn: 1.00-1.50%; Cr: 0.30-0.50%; Mo: 0.30-0.50%; Ni: 0.20-0.50%; B: 0.0010-0.0030%; Nb: 0.010-0.030%; V: 0.030-0.050%; Ti: 0.010-0.020%; Alt: 0.030-0.050%; P≤0.020%; S≤0.010%, and the rest is Fe and unavoidable impurities, and Mo: 0.30-0.50% is also added to the steel.

中国发明专利CN116676541A公开了一种低成本960MPa级超高强韧钢板，其化学成分质量百分比为：C：0.18-0.25％，Mn：1.6-1.8％，Cr：0.5-0.6％，V：0.04-0.06％，Ti：0.01-0.02％，B：0.001-0.002％，其余为Fe及不可避免杂质。虽然钢种不添加Mo元素，但其主要利用更高的C和Mn含量提高强度。Chinese invention patent CN116676541A discloses a low-cost 960MPa ultra-high strength steel plate, whose chemical composition mass percentage is: C: 0.18-0.25%, Mn: 1.6-1.8%, Cr: 0.5-0.6%, V: 0.04-0.06%, Ti: 0.01-0.02%, B: 0.001-0.002%, and the rest is Fe and unavoidable impurities. Although the steel does not add Mo element, it mainly uses higher C and Mn content to improve strength.

若在碳当量较低且Mo含量较低时，调质后的强度难以达到1000MPa。如中国发明专利CN114318120A公开了一种800MPa级工程机械用高强钢，其Mo含量：0.10～0.30％，屈服强度只能保证≥800MPa。If the carbon equivalent is low and the Mo content is low, the strength after quenching and tempering is difficult to reach 1000MPa. For example, Chinese invention patent CN114318120A discloses an 800MPa high-strength steel for engineering machinery, whose Mo content is 0.10-0.30%, and the yield strength can only be guaranteed to be ≥800MPa.

近年来，Mo合金的价格暴涨，显著提升了此类产品的合金成本和钢材价格，限制了其市场的扩展和更广泛的应用。因此，亟需开发低Mo合金含量的高强度调质高强钢。In recent years, the price of Mo alloys has skyrocketed, significantly increasing the alloy cost and steel price of such products, limiting the expansion of their market and wider application. Therefore, it is urgent to develop high-strength quenched and tempered high-strength steel with low Mo alloy content.

发明内容Summary of the invention

本发明的目的在于提供一种屈服强度1000MPa级调质钢板及其生产方法，所述调质钢板的屈服强度≥1000MPa，抗拉强度≥1050MPa，延伸率＞18％，-40℃冲击功＞120J，在实现钢板超高强度的同时成本低廉，综合性能良好。The purpose of the present invention is to provide a quenched and tempered steel plate with a yield strength of 1000MPa and a production method thereof. The quenched and tempered steel plate has a yield strength of ≥1000MPa, a tensile strength of ≥1050MPa, an elongation of >18%, and an impact energy of -40°C of >120J. While achieving ultra-high strength of the steel plate, the cost is low and the comprehensive performance is good.

为达到上述目的，本发明的技术方案是：To achieve the above object, the technical solution of the present invention is:

一种屈服强度1000MPa级调质钢板，其成分重量百分比为：C：0.150～0.200％，Si：0.05～0.30％，Mn：0.80～1.60％，Cr≥0.6％，Mo≤0.20％，V≥0.060％，N≤0.0050％，P≤0.030％，S≤0.0050％，O≤0.0040％，其余包括Fe和其它不可避免的夹杂；且上述元素含量必须同时满足如下关系：A quenched and tempered steel plate with a yield strength of 1000 MPa, wherein the composition by weight percentage is: C: 0.150-0.200%, Si: 0.05-0.30%, Mn: 0.80-1.60%, Cr≥0.6%, Mo≤0.20%, V≥0.060%, N≤0.0050%, P≤0.030%, S≤0.0050%, O≤0.0040%, and the rest includes Fe and other unavoidable inclusions; and the contents of the above elements must simultaneously satisfy the following relationship:

1.00％≤3Mo+0.6Cr+5V≤1.50％。1.00%≤3Mo+0.6Cr+5V≤1.50%.

进一步，所述钢板还包括Nb、Ti、Cu、Ni、B、Al、Ca和RE中的一种或几 种，且其含量满足：Nb≤0.050％，Ti≤0.050％，Cu≤0.50％，Ni≤0.50％，B≤0.0030％，Al≤0.06％，Ca≤0.0040％，RE≤0.0050％。Furthermore, the steel plate further comprises one or more of Nb, Ti, Cu, Ni, B, Al, Ca and RE. The content of the above-mentioned alloys shall meet the following requirements: Nb≤0.050%, Ti≤0.050%, Cu≤0.50%, Ni≤0.50%, B≤0.0030%, Al≤0.06%, Ca≤0.0040%, and RE≤0.0050%.

更进一步，其余为Fe和其它不可避免的夹杂。Furthermore, the remainder is Fe and other inevitable inclusions.

本发明钢板的显微组织为回火马氏体+50nm以内的渗碳体+2-10nm的Cr7C3和VC或(V,Mo)C碳化物。The microstructure of the steel plate of the present invention is tempered martensite + cementite within 50nm + Cr7C3 and VC or (V, Mo)C carbides with a size of 2-10nm.

本发明钢板的屈服强度≥1000MPa，抗拉强度≥1050MPa，延伸率＞18％，-40℃冲击功＞120J。The steel plate of the present invention has a yield strength of ≥1000MPa, a tensile strength of ≥1050MPa, an elongation of >18%, and an impact energy of >120J at -40°C.

在一些实施方案中，本发明钢板的屈服强度≥1030MPa。在一些实施方案中，本发明钢板的屈服强度为1000～1150MPa。In some embodiments, the yield strength of the steel plate of the present invention is ≥ 1030 MPa. In some embodiments, the yield strength of the steel plate of the present invention is 1000-1150 MPa.

在一些实施方案中，本发明钢板的抗拉强度≥1080MPa。在一些实施方案中，本发明钢板的抗拉强度为1050～1170MPa。In some embodiments, the tensile strength of the steel plate of the present invention is ≥ 1080 MPa. In some embodiments, the tensile strength of the steel plate of the present invention is 1050-1170 MPa.

在一些实施方案中，本发明钢板的延伸率≥19％。在一些实施方案中，本发明钢板的延伸率为19～23％。In some embodiments, the elongation of the steel sheet of the present invention is ≥ 19%. In some embodiments, the elongation of the steel sheet of the present invention is 19-23%.

在一些实施方案中，本发明钢板的-40℃冲击功≥150J。在一些实施方案中，本发明钢板的-40℃冲击功为125～220J，优选为150～220J。In some embodiments, the -40°C impact energy of the steel plate of the present invention is ≥ 150 J. In some embodiments, the -40°C impact energy of the steel plate of the present invention is 125 to 220 J, preferably 150 to 220 J.

在本发明钢板成分设计中：In the steel plate composition design of the present invention:

C：C是钢中的基本元素，也是强化马氏体钢的重要元素。0.15％以上的C能保证淬火态钢板的强度；然而，C含量较高会导致整体C当量的提高，焊接时容易产生裂纹。因此，本发明C含量控制在0.15～0.20％。C: C is a basic element in steel and an important element for strengthening martensitic steel. C above 0.15% can ensure the strength of the quenched steel plate; however, a higher C content will lead to an increase in the overall C equivalent, which is prone to cracking during welding. Therefore, the C content of the present invention is controlled at 0.15-0.20%.

Si：0.05％以上的Si可以起到较好的脱氧作用，Si超过0.3％容易产生红铁皮，本发明硅含量控制在0.05～0.30％。Si: Si above 0.05% can play a good deoxidation role, and Si exceeding 0.3% is prone to produce red iron scale. The silicon content of the present invention is controlled within the range of 0.05-0.30%.

Mn：Mn元素在0.8％以上可以提高钢的淬透性，Mn含量超过1.6％容易产生偏析和MnS等夹杂物，恶化马氏体高强钢的韧性，本发明Mn含量控制在0.80～1.60％。Mn: Mn element can improve the hardenability of steel when it is above 0.8%. When the Mn content exceeds 1.6%, it is easy to produce segregation and inclusions such as MnS, which deteriorates the toughness of martensitic high-strength steel. In the present invention, the Mn content is controlled at 0.80-1.60%.

Cr：Cr元素可以提高钢的淬透性，有利于在淬火时形成全马氏体组织；此外，具有抗回火软化的作用。研究发现，当Cr含量≥0.60％，在高温回火过程中还可形成Cr的碳化物Cr7C3，起到析出强化或二次硬化的作用。因此，本发明控制Cr含量≥0.60％。在一些实施方案中，本发明控制Cr含量为0.60～1.6％。Cr: Cr can improve the hardenability of steel and is conducive to the formation of full martensite structure during quenching; in addition, it has the effect of resisting tempering softening. Studies have found that when the Cr content is ≥0.60%, Cr carbide Cr 7 C 3 can also be formed during high-temperature tempering, which plays a role of precipitation strengthening or secondary hardening. Therefore, the present invention controls the Cr content to be ≥0.60%. In some embodiments, the present invention controls the Cr content to be 0.60-1.6%.

Mo：Mo元素可以提高钢的淬透性，有利于在淬火时形成全马氏体组织；Mo 在高温回火时可抑制碳化物的长大粗化，具有抗高温回火软化和焊接接头软化的作用；然而，Mo含量太高会导成本显著增加。因此，本发明控制Mo含量≤0.20％。Mo: Mo element can improve the hardenability of steel and is conducive to the formation of full martensite structure during quenching; Mo During high temperature tempering, the growth and coarsening of carbides can be suppressed, and the softening of high temperature tempering and weld joints can be resisted; however, too high Mo content will significantly increase the cost. Therefore, the present invention controls the Mo content to be ≤0.20%.

V：V元素可以细化晶粒，提高钢的韧性。V在回火过程中与C反应形成碳化物，起到析出强化效果，抵抗回火软化，提高调质钢的强度。因此，本发明控制V含量≥0.060％。在一些实施方案中，本发明控制V含量为0.060～0.130％。V: The V element can refine the grains and improve the toughness of the steel. V reacts with C during the tempering process to form carbides, which have a precipitation strengthening effect, resist tempering softening, and improve the strength of the quenched and tempered steel. Therefore, the present invention controls the V content to be ≥ 0.060%. In some embodiments, the present invention controls the V content to be 0.060-0.130%.

Cr、Mo和V为强碳化物形成元素，三者与C的亲和力大于Fe与C的亲和力，因此能抑制C与Fe结合形成渗碳体，同时抑制渗碳体的粗化。抑制渗碳体析出或者粗化，会提高固溶在马氏体中的C含量，提高基体马氏体的强度，另一方面也可抑制回火脆性的发生。此外，在高温回火时Mo、Cr、V能与C反应形成纳米级碳化物，起到析出强化的作用。因此Mo、Cr和V起到抗回火软化的作用，提高钢板强度。但是Cr和V的含量过多时，在高温回火时合金碳化物Cr7C3和VC会粗化，尤其是V的合金碳化物VC，很容易粗化，降低析出强化效率，同时显著恶化钢板的韧性。Cr, Mo and V are strong carbide forming elements, and their affinity with C is greater than that of Fe with C, so they can inhibit C from combining with Fe to form cementite, and inhibit the coarsening of cementite. Inhibiting the precipitation or coarsening of cementite can increase the C content dissolved in martensite, improve the strength of matrix martensite, and on the other hand, can also inhibit the occurrence of temper brittleness. In addition, Mo, Cr, V can react with C to form nano-scale carbides during high-temperature tempering, which plays a role in precipitation strengthening. Therefore, Mo, Cr and V play a role in tempering softening resistance, and improve the strength of steel plate. However, when the content of Cr and V is too much, alloy carbides Cr 7 C 3 and VC will coarsen during high-temperature tempering, especially the alloy carbides VC of V, which are easy to coarsen, reduce the precipitation strengthening efficiency, and significantly deteriorate the toughness of the steel plate.

因此，需要控制Mo、Cr和V的含量在合理的范围内，一方面能起到抑制渗碳体粗化的作用，另一方面避免自身形成合金碳化物的长大。根据Mo、Cr和V三个元素与C结合力的强弱以及合金碳化物析出效果的强弱，可定义析出相控制指数PCI＝3Mo+0.6Cr+5V。实验表明，PCI≥1％时可显著抑制渗碳体的析出，并将析出的渗碳体尺寸大小(非球体时指最大长度，球体时指直径)控制在50nm以内，保证基体马氏体的强度和韧性。当PCI≤1.5％时，Cr7C3和VC或(V,Mo)C析出相尺寸(非球体时指最大长度，球体时指直径)在2～10nm，能起到显著的析出强化效果，保证钢板高温回火后的强度。当PCI≥1.5％时，VC或(V,Mo)C析出相粗化较为严重，降低析出强化效率且显著降低韧性；同时，Mo、Cr和V过高也会显著提高钢的成本。因此，本发明设定PCI范围为：1.00％≤PCI≤1.50％。在一些实施方案中，本发明设定PCI范围为：1.05％≤3Mo+0.6Cr+5V≤1.50％。在一些实施方案中，本发明设定PCI范围为：1.15％≤3Mo+0.6Cr+5V≤1.50％。Therefore, it is necessary to control the content of Mo, Cr and V within a reasonable range, which can inhibit the coarsening of cementite on the one hand, and avoid the growth of alloy carbides on the other hand. According to the strength of the binding force between Mo, Cr and V and C and the precipitation effect of alloy carbides, the precipitation phase control index PCI = 3Mo + 0.6Cr + 5V can be defined. Experiments show that when PCI ≥ 1%, the precipitation of cementite can be significantly inhibited, and the size of the precipitated cementite (maximum length for non-spherical and diameter for spherical) can be controlled within 50nm to ensure the strength and toughness of the matrix martensite. When PCI ≤ 1.5%, the size of the precipitated phases of Cr 7 C 3 and VC or (V, Mo) C (maximum length for non-spherical and diameter for spherical) is 2 to 10nm, which can play a significant precipitation strengthening effect and ensure the strength of the steel plate after high temperature tempering. When PCI ≥ 1.5%, the VC or (V, Mo) C precipitation phase coarsens more seriously, reducing the precipitation strengthening efficiency and significantly reducing toughness; at the same time, too high Mo, Cr and V will also significantly increase the cost of steel. Therefore, the present invention sets the PCI range to: 1.00% ≤ PCI ≤ 1.50%. In some embodiments, the present invention sets the PCI range to: 1.05% ≤ 3Mo + 0.6Cr + 5V ≤ 1.50%. In some embodiments, the present invention sets the PCI range to: 1.15% ≤ 3Mo + 0.6Cr + 5V ≤ 1.50%.

Ni：Ni元素具有促进塑性流动的作用，提高钢的塑性和韧性；Ni含量太高会导致碳当量提高，恶化焊接性能，同时Ni属于贵金属，会提高成本。因此，本发明控制Ni含量≤0.50％。Ni: Ni element has the function of promoting plastic flow, improving the plasticity and toughness of steel; too high Ni content will lead to an increase in carbon equivalent, deteriorating welding performance, and Ni is a precious metal, which will increase the cost. Therefore, the present invention controls the Ni content to ≤ 0.50%.

Cu：Cu元素在回火时可以产生一定的沉淀强化作用，此外添加一定的Cu元 素可以提高工程机械用超高强钢的耐腐蚀性。因此，本发明控制Cu含量≤0.50％。Cu: Cu element can produce a certain precipitation strengthening effect during tempering. In addition, adding a certain amount of Cu element The element can improve the corrosion resistance of ultra-high strength steel for engineering machinery. Therefore, the present invention controls the Cu content to be ≤0.50%.

Nb：Nb为微合金元素，与C、N等元素形成纳米级析出物，在加热时抑制奥氏体晶粒的长大；Nb可以提高未再结晶临界温度Tnr，扩大生产窗口。因此，本发明控制铌含量≤0.050％。Nb: Nb is a microalloying element, which forms nano-scale precipitates with elements such as C and N, inhibiting the growth of austenite grains during heating; Nb can increase the non-recrystallization critical temperature Tnr and expand the production window. Therefore, the present invention controls the niobium content to ≤ 0.050%.

Ti：Ti元素可以与N元素反应，消耗基体中N，减少N元素对性能的恶化；Ti元素还具有细化晶粒的作用，提高钢的韧性；过多的Ti会导致TiN夹杂物的粗化，恶化钢的韧性。因此，本发明控制Ti含量≤0.05％。Ti: Ti can react with N to consume N in the matrix and reduce the deterioration of performance caused by N. Ti also refines grains and improves the toughness of steel. Too much Ti will cause the coarsening of TiN inclusions and deteriorate the toughness of steel. Therefore, the present invention controls the Ti content to ≤0.05%.

B：微量的B可以提高钢的淬透性，提高钢的强度；然而，超过0.0030％的B容易产生偏析，形成碳硼化合物，严重恶化钢的韧性以及焊接性能。因此，本发明控制硼含量≤0.0030％。B: A trace amount of B can improve the hardenability and strength of steel; however, B exceeding 0.0030% is prone to segregation and forms carbon-boron compounds, which seriously deteriorates the toughness and welding performance of steel. Therefore, the present invention controls the boron content to ≤ 0.0030%.

RE：稀土元素可以改善钢中夹杂物的形貌，使夹杂物更加细小弥散，尤其是对于本发明的高Ti成分钢种，能显著改善TiN夹杂物的尺寸形貌，提升钢的韧性和疲劳性能。过多的稀土元素导致成本提高。因此，本发明控制RE含量≤0.0050％。RE: Rare earth elements can improve the morphology of inclusions in steel, making the inclusions smaller and more dispersed. Especially for the high Ti content steel of the present invention, it can significantly improve the size and morphology of TiN inclusions and improve the toughness and fatigue performance of steel. Too much rare earth elements will increase the cost. Therefore, the present invention controls the RE content to ≤0.0050%.

Al：作为脱氧剂，同时可细化晶粒，提高冲击韧性，Al含量超过0.06％容易产生Al的氧化物夹杂缺陷。因此，本发明控制Al含量≤0.06％。Al: As a deoxidizer, it can refine the grains and improve the impact toughness. When the Al content exceeds 0.06%, Al oxide inclusion defects are likely to occur. Therefore, the Al content is controlled to be ≤ 0.06% in the present invention.

Ca：Ca元素可以在钢冶炼过程中起到净化剂作用，改善钢的韧性；然而，Ca含量超过0.0040％容易形成尺寸较大的Ca的化合物，反而会恶化韧性。因此，本发明控制Ca含量≤0.0040％。Ca: Ca can act as a purifier in the steel smelting process and improve the toughness of the steel; however, when the Ca content exceeds 0.0040%, it is easy to form Ca compounds with larger sizes, which will deteriorate the toughness. Therefore, the present invention controls the Ca content to ≤ 0.0040%.

N：本发明要求严格控制N元素的范围，N含量超过0.0050％容易导致形成粗大的析出物颗粒，恶化韧性。因此，本发明控制N含量≤0.0050％。N: The present invention requires strict control of the range of N element. If the N content exceeds 0.0050%, it will easily lead to the formation of coarse precipitate particles, which will deteriorate the toughness. Therefore, the present invention controls the N content to be ≤ 0.0050%.

P、S和O：P、S和O作为杂质元素影响钢的塑、韧性，本发明对其控制范围分别为P≤0.030％，S≤0.0050％，O≤0.0040％。P, S and O: P, S and O as impurity elements affect the plasticity and toughness of steel. The control ranges of the present invention are P≤0.030%, S≤0.0050%, and O≤0.0040%, respectively.

本发明所述屈服强度1000MPa级调质钢板的生产方法，其包括如下步骤：The method for producing a quenched and tempered steel plate with a yield strength of 1000 MPa of the present invention comprises the following steps:

1)冶炼、铸造1) Smelting and casting

按上述成分冶炼、铸造成板坯；Smelting and casting into slabs according to the above ingredients;

2)加热2) Heating

加热温度1200～1250℃，待铸坯心部到温后开始保温，保温时间＞1.5h；The heating temperature is 1200-1250℃. When the core of the ingot reaches the temperature, the insulation begins. The insulation time is more than 1.5h.

3)轧制 3) Rolling

终轧温度为820～920℃；The final rolling temperature is 820-920°C;

4)冷却、卷取4) Cooling and coiling

轧后钢板以≥60℃/s的冷却速度冷却至500～700℃后卷取，然后空冷至室温；The rolled steel plate is cooled to 500-700°C at a cooling rate of ≥60°C/s, then coiled and air-cooled to room temperature;

5)热处理5) Heat treatment

淬火处理，将钢板加热到820～950℃，钢板心部到温后保温5～40min，以≥20℃/s的冷速快速冷却至室温；Quenching treatment: heat the steel plate to 820-950℃, keep the temperature for 5-40min after the core of the steel plate reaches the temperature, and then quickly cool it to room temperature at a cooling rate of ≥20℃/s;

回火处理，回火温度为450～650℃，钢板心部到温后保温，保温时间≥5min，最后空冷至室温。Tempering treatment, the tempering temperature is 450-650℃, the core of the steel plate is kept warm after reaching the temperature, the holding time is ≥5min, and finally air-cooled to room temperature.

优选的，终轧压下率为15～20％。Preferably, the final rolling reduction ratio is 15 to 20%.

在本发明所述制造方法中：In the manufacturing method of the present invention:

淬火处理中，淬火温度为820～950℃，温度在820℃以上，是为了保证钢板能完全奥氏体化；温度在950℃以下，是为了防止奥氏体晶粒粗化，恶化钢的韧性；以≥20℃/s冷却至室温是为了获得全马氏体组织，保证钢的强度。During the quenching treatment, the quenching temperature is 820-950℃. The temperature above 820℃ is to ensure that the steel plate can be completely austenitized; the temperature below 950℃ is to prevent the coarsening of austenite grains and deterioration of the toughness of the steel; cooling to room temperature at ≥20℃/s is to obtain a full martensitic structure and ensure the strength of the steel.

回火处理中，由于本发明所述成分体系的钢回火温度超过450℃且钢板心部达到炉温后保温5min以上，确保合金中Mo、Cr和V在该温度范围内能与C反应形成细小的Cr7C3和VC或(V,Mo)C析出相，带来析出强化，提高钢的屈服强度；同时可以有效去除钢板内应力，使马氏体内部位错发生回复提高钢的塑性；回火温度超过650℃，合金碳化物发生粗化，会恶化钢的韧性；通过调整回火温度和时间可以实现强塑性的最佳匹配。During the tempering treatment, since the tempering temperature of the steel of the component system of the present invention exceeds 450°C and the steel plate core is kept warm for more than 5 minutes after reaching the furnace temperature, it is ensured that Mo, Cr and V in the alloy can react with C within the temperature range to form fine Cr 7 C 3 and VC or (V, Mo) C precipitation phases, which brings precipitation strengthening and improves the yield strength of the steel; at the same time, the internal stress of the steel plate can be effectively removed, and the internal dislocation of the martensite can be restored to improve the plasticity of the steel; when the tempering temperature exceeds 650°C, the alloy carbides will coarsen and the toughness of the steel will be deteriorated; the best matching of strength and plasticity can be achieved by adjusting the tempering temperature and time.

在一些实施方案中，步骤2)的加热保温时间为1.6～3.0小时。In some embodiments, the heating and heat preservation time of step 2) is 1.6 to 3.0 hours.

在一些实施方案中，步骤4)的冷却速度为60～150℃/s。In some embodiments, the cooling rate in step 4) is 60-150° C./s.

在一些实施方案中，步骤5)的冷速≥50℃/s，优选≥80℃/s。在一些实施方案中，步骤5)的冷速为20～250℃/s，或者为50～250℃/s。In some embodiments, the cooling rate of step 5) is ≥50°C/s, preferably ≥80°C/s. In some embodiments, the cooling rate of step 5) is 20-250°C/s, or 50-250°C/s.

在一些实施方案中，步骤5)的回火加热温度为480～650℃。In some embodiments, the tempering heating temperature in step 5) is 480-650°C.

在一些实施方案中，步骤5)的保温时间为5～30min。In some embodiments, the insulation time of step 5) is 5 to 30 minutes.

本发明的有益效果：Beneficial effects of the present invention:

本发明在成分设计上，采用低Mo甚至无Mo且C、Mn含量较低，利用高Cr和V的元素添加，控制1.00％≤3Mo+0.6Cr+5V≤1.50％，抑制渗碳体的析出，并 将析出的渗碳体控制在50nm以内，形成的Cr7C3和VC或(V,Mo)C析出相，利用其抗回火软化和析出强化效果，实现钢板的高强度。与常规采用添加较高含量的Mo元素以抵抗回火时的软化使屈服强度大于1000MPa的超高强度钢相比，降低了成本，也避免了在无Mo元素添加，需要添加更高的C和Mn元素含量对焊接性能的不利影响。In the composition design, the present invention adopts low Mo or even no Mo and low C and Mn content, and uses high Cr and V element addition to control 1.00%≤3Mo+0.6Cr+5V≤1.50%, inhibits the precipitation of cementite, and The precipitated cementite is controlled within 50nm, and the precipitated Cr 7 C 3 and VC or (V,Mo) C phases are formed, and the high strength of the steel plate is achieved by utilizing its tempering softening resistance and precipitation strengthening effect. Compared with the conventional ultra-high strength steel that uses a higher content of Mo element to resist softening during tempering to make the yield strength greater than 1000MPa, the cost is reduced and the adverse effect of adding higher C and Mn element contents on welding performance is avoided when no Mo element is added.

本发明在成分设计基础上，通过控制淬火和回火热处理的温度和时间，防止晶粒的粗化，对渗碳体、Cr7C3和VC或(V,Mo)C碳化物的尺寸进行控制，渗碳体尺寸大小控制在50nm以内，形成尺寸大小2～10nm的Cr7C3和VC或(V,Mo)C析出相，获得最佳的析出强化效果，获得最佳的强塑性匹配，从而在较低的合金含量下实现超高的强度。The invention controls the temperature and time of quenching and tempering heat treatment on the basis of component design to prevent grain coarsening and control the size of cementite, Cr7C3 and VC or (V, Mo)C carbides. The size of cementite is controlled within 50nm, and Cr7C3 and VC or (V, Mo)C precipitation phases with a size of 2-10nm are formed, thereby obtaining the best precipitation strengthening effect and the best strength-plasticity matching, thereby realizing ultra-high strength at a lower alloy content.

附图说明BRIEF DESCRIPTION OF THE DRAWINGS

图1为本发明实施例4钢板热处理后的金相组织照片；FIG1 is a metallographic structure photograph of a steel plate after heat treatment in Example 4 of the present invention;

图2为本发明实施例4钢板热处理后的扫描电子显微组织照片。FIG. 2 is a scanning electron microscopic photograph of the steel plate after heat treatment in Example 4 of the present invention.

具体实施方式DETAILED DESCRIPTION

下面结合实施例和附图对本发明做进一步说明。The present invention will be further described below in conjunction with the embodiments and drawings.

本发明钢实施例成分参见表1，本发明钢实施例制造工艺参数参见表2。The composition of the steel example of the present invention is shown in Table 1, and the manufacturing process parameters of the steel example of the present invention are shown in Table 2.

由图1中照片上可以看出，热处理后的组织为回火马氏体组织。图2的扫描电子显微组织照片中可看到组织中存在大量弥散分布的纳米级析出物，其中尺寸稍大的为50nm以下的渗碳体，尺寸极细的为2-10nm的Cr7C3和VC或(V,Mo)C。It can be seen from the photo in Figure 1 that the microstructure after heat treatment is tempered martensite. The scanning electron microscopic microstructure photo in Figure 2 shows that there are a large number of dispersed nano-scale precipitates in the microstructure, among which the slightly larger ones are cementite below 50nm, and the very fine ones are Cr 7 C 3 and VC or (V, Mo) C of 2-10nm.

根据国标GB/T228.1-2010《金属材料拉伸试验标准》对实施例进行了力学性能测试，将各实施例中的调质处理后的钢板进行横向拉伸和纵向冲击试验，各实施例样板对应的性能如表3所示。The mechanical properties of the embodiments were tested according to the national standard GB/T228.1-2010 "Standard for Tensile Test of Metallic Materials". The steel plates after quenching and tempering in each embodiment were subjected to transverse tensile and longitudinal impact tests. The corresponding properties of the samples in each embodiment are shown in Table 3.

从力学性能上看，本发明钢具有超高的强度，屈服强度≥1000MPa，抗拉强度≥1050MPa，延伸率在18％以上，-40℃冲击功＞120J。这得益于本发明的实施例具有特定元素组成，特别是具有特定的Cr、Mo、V元素组合，确保钢板在高温回火条件下仍然保持较高的强度；同时，较高的回火温度保证了钢板的高延伸率和韧性，实现良好的强塑性配合。 From the perspective of mechanical properties, the steel of the present invention has ultra-high strength, yield strength ≥ 1000MPa, tensile strength ≥ 1050MPa, elongation above 18%, and -40°C impact energy > 120J. This is due to the specific element composition of the embodiment of the present invention, especially the specific combination of Cr, Mo, and V elements, which ensures that the steel plate still maintains high strength under high-temperature tempering conditions; at the same time, the high tempering temperature ensures the high elongation and toughness of the steel plate, achieving a good combination of strength and plasticity.

对比例1中3Mo+0.6Cr+5V总体含量过低，强度达不到本发明要求。对比例2中3Mo+0.6Cr+5V总体含量过低，强度虽然能达到本发明的要求，但是-40℃冲击功较低，在70J左右，不能满足韧性的要求。The overall content of 3Mo+0.6Cr+5V in Comparative Example 1 is too low, and the strength does not meet the requirements of the present invention. The overall content of 3Mo+0.6Cr+5V in Comparative Example 2 is too low, and although the strength can meet the requirements of the present invention, the impact energy at -40°C is low, at about 70J, which cannot meet the toughness requirements.

对比例3中虽然成分都满足本发明的要求，但是由于热处理过程中回火温度过高，导致钢的强度和韧性均较低。对比例4虽然成分都满足本发明的要求，但是回火温度低，虽然强度能达到本发明要求，但是延伸率和冲击功均较低，塑性较差。Although the components of Comparative Example 3 meet the requirements of the present invention, the tempering temperature is too high during the heat treatment process, resulting in low strength and toughness of the steel. Although the components of Comparative Example 4 meet the requirements of the present invention, the tempering temperature is low, and although the strength can meet the requirements of the present invention, the elongation and impact energy are low, and the plasticity is poor.

本发明所述屈服强度1000MPa级调质钢可用于各种要求使用高强度钢的领域，特别是同时要求高强度和高韧性的工程机械用钢板的用途。 The quenched and tempered steel with a yield strength of 1000 MPa described in the present invention can be used in various fields requiring the use of high-strength steel, especially in the use of steel plates for engineering machinery requiring both high strength and high toughness.

表1(单位：重量百分比)

注：式1＝3Mo+0.6Cr+5V Table 1 (Unit: weight percentage)

Note: Formula 1 = 3Mo + 0.6Cr + 5V

表2
Table 2

表3
Table 3

Claims (15)

一种屈服强度1000MPa级调质钢板，其成分重量百分比为：C：0.150-0.20％，Si：0.05-0.3％，Mn：0.80-1.60％，Cr≥0.6％，Mo≤0.20％，V≥0.060％，N≤0.0050％，P≤0.030％，S≤0.0050％，O≤0.0040％，其余包括Fe和其它不可避免的夹杂；且上述元素含量必须同时满足如下关系：
1.00％≤3Mo+0.6Cr+5V≤1.50％。A quenched and tempered steel plate with a yield strength of 1000 MPa, wherein the composition by weight percentage is: C: 0.150-0.20%, Si: 0.05-0.3%, Mn: 0.80-1.60%, Cr≥0.6%, Mo≤0.20%, V≥0.060%, N≤0.0050%, P≤0.030%, S≤0.0050%, O≤0.0040%, and the rest includes Fe and other unavoidable inclusions; and the contents of the above elements must simultaneously satisfy the following relationship:
1.00%≤3Mo+0.6Cr+5V≤1.50%. 如权利要求1所述的屈服强度1000MPa级调质钢板，其特征在于，所述钢板还包括Nb、Ti、Cu、Ni、B、Al、Ca和RE中的一种或几种，且其含量满足：Nb≤0.050％，Ti≤0.050％，Cu≤0.50％，Ni≤0.50％，B≤0.0030％，Al≤0.06％，Ca≤0.0040％，RE≤0.0050％。The quenched and tempered steel plate with a yield strength of 1000 MPa as described in claim 1 is characterized in that the steel plate also includes one or more of Nb, Ti, Cu, Ni, B, Al, Ca and RE, and their contents satisfy: Nb≤0.050%, Ti≤0.050%, Cu≤0.50%, Ni≤0.50%, B≤0.0030%, Al≤0.06%, Ca≤0.0040%, RE≤0.0050%. 如权利要求1所述的屈服强度1000MPa级调质钢板，其特征在于，Cr的含量为0.6～1.6％。The quenched and tempered steel plate with a yield strength of 1000 MPa as claimed in claim 1, wherein the Cr content is 0.6-1.6%. 如权利要求1所述的屈服强度1000MPa级调质钢板，其特征在于，V的含量为0.060～0.130％。The quenched and tempered steel plate with a yield strength of 1000 MPa as claimed in claim 1, wherein the V content is 0.060-0.130%. 如权利要求1所述的屈服强度1000MPa级调质钢板，其特征在于，1.05％≤3Mo+0.6Cr+5V≤1.50％，或1.15％≤3Mo+0.6Cr+5V≤1.50％。The quenched and tempered steel plate with a yield strength of 1000 MPa as claimed in claim 1, characterized in that 1.05%≤3Mo+0.6Cr+5V≤1.50%, or 1.15%≤3Mo+0.6Cr+5V≤1.50%. 如权利要求1～5中任一项所述的屈服强度1000MPa级调质钢板，其特征在于，其余为Fe和其它不可避免的夹杂。The quenched and tempered steel plate with a yield strength of 1000 MPa as claimed in any one of claims 1 to 5, characterized in that the remainder is Fe and other inevitable inclusions. 如权利要求1～6中任一项所述的屈服强度1000MPa级调质钢板，其特征在于，所述钢板的显微组织为回火马氏体+50nm以内的渗碳体+2～10nm的Cr7C3和VC或(V,Mo)C碳化物。The quenched and tempered steel plate with a yield strength of 1000 MPa according to any one of claims 1 to 6, characterized in that the microstructure of the steel plate is tempered martensite + cementite within 50 nm + Cr 7 C 3 and VC or (V, Mo) C carbides of 2 to 10 nm. 如权利要求1～7中任一项所述的屈服强度1000MPa级调质钢板，其特征在于，所述钢板的屈服强度≥1000MPa，抗拉强度≥1050MPa，延伸率＞18％，-40℃冲击功＞120J。The quenched and tempered steel plate with a yield strength of 1000 MPa as described in any one of claims 1 to 7, characterized in that the yield strength of the steel plate is ≥1000 MPa, the tensile strength is ≥1050 MPa, the elongation is >18%, and the impact energy at -40°C is >120 J. 如权利要求8所述的屈服强度1000MPa级调质钢板，其特征在于，所述钢板的屈服强度≥1030MPa，或者为1000～1150MPa；所述钢板的抗拉强度≥1080MPa，或者为1050～1170MPa；所述钢板的延伸率≥19％，如19-23％；和/或， 所述钢板的-40℃冲击功≥150J，或者为125～220J或150～220J。The quenched and tempered steel plate with a yield strength of 1000 MPa as claimed in claim 8, characterized in that the yield strength of the steel plate is ≥1030 MPa, or 1000-1150 MPa; the tensile strength of the steel plate is ≥1080 MPa, or 1050-1170 MPa; the elongation of the steel plate is ≥19%, such as 19-23%; and/or, The -40°C impact energy of the steel plate is ≥150J, or is 125-220J or 150-220J. 如权利要求1～9任一项所述屈服强度1000MPa级调质钢板的生产方法，其特征是，包括如下步骤：The method for producing a quenched and tempered steel plate with a yield strength of 1000 MPa as claimed in any one of claims 1 to 9, characterized in that it comprises the following steps: 1)冶炼、铸造1) Smelting and casting 按权利要求1或2或3或4或5所述成分冶炼、铸造成板坯；Smelting and casting the composition according to claim 1, 2, 3, 4 or 5 into a slab; 2)加热2) Heating 加热温度1200～1250℃，待铸坯心部到温后开始保温，保温时间＞1.5h；The heating temperature is 1200-1250℃. When the core of the ingot reaches the temperature, the insulation begins. The insulation time is more than 1.5h. 3)轧制3) Rolling 终轧温度为820～920℃；The final rolling temperature is 820-920°C; 4)冷却、卷取4) Cooling and coiling 轧后钢板以≥60℃/s的冷却速度冷却至500～700℃后卷取，然后空冷至室温；The rolled steel plate is cooled to 500-700°C at a cooling rate of ≥60°C/s, then coiled and air-cooled to room temperature; 5)热处理5) Heat treatment 淬火处理，将钢板加热到820～950℃，钢板心部到温后保温5～40min，以≥20℃/s的冷速快速冷却至室温；Quenching treatment: heat the steel plate to 820-950℃, keep the temperature for 5-40min after the core of the steel plate reaches the temperature, and then quickly cool it to room temperature at a cooling rate of ≥20℃/s; 回火处理，回火温度为450～650℃，钢板心部到温后保温，保温时间≥5min，最后空冷至室温。Tempering treatment, the tempering temperature is 450-650℃, the core of the steel plate is kept warm after reaching the temperature, the holding time is ≥5min, and finally air-cooled to room temperature. 如权利要求10所述的生产方法，其特征是，步骤3)中，终轧压下率为15～20％。The production method according to claim 10, characterized in that in step 3), the final rolling reduction rate is 15-20%. 如权利要求10所述的生产方法，其特征是，步骤2)的加热保温时间为1.6～3.0小时。The production method according to claim 10, characterized in that the heating and heat preservation time in step 2) is 1.6 to 3.0 hours. 如权利要求10所述的生产方法，其特征是，步骤4)的冷却速度为60～150℃/s。The production method according to claim 10, characterized in that the cooling rate of step 4) is 60 to 150°C/s. 如权利要求10所述的生产方法，其特征是：The production method according to claim 10, characterized in that: 步骤5)的冷速≥50℃/s，优选≥80℃/s；或The cooling rate in step 5) is ≥50°C/s, preferably ≥80°C/s; or 步骤5)的冷速为20～250℃/s，或者为50～250℃/s。The cooling rate in step 5) is 20 to 250°C/s, or 50 to 250°C/s. 如权利要求10所述的生产方法，其特征是：The production method according to claim 10, characterized in that: 步骤5)的回火加热温度为480～650℃；和/或The tempering heating temperature in step 5) is 480-650° C.; and/or 步骤5)的保温时间为5～30min。 The insulation time of step 5) is 5 to 30 minutes.
PCT/CN2024/124128 2023-10-11 2024-10-11 Tempered steel plate having yield strength of 1000 mpa and production method therefor Pending WO2025077826A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120738568A (en) * 2025-09-05 2025-10-03 鞍钢股份有限公司 800 MPa-level steel plate for marine environment ore conveying pipeline and production method thereof

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06122936A (en) * 1992-10-12 1994-05-06 Nkk Corp Ultra-high-strength thin steel sheet excellent in hydrogen-delayed cracking resistance and manufacturing method thereof
CN101613831A (en) * 2008-06-27 2009-12-30 宝山钢铁股份有限公司 Non-modified high-hardness hot rolled steel and manufacture method and application
CN104513936A (en) * 2014-12-19 2015-04-15 宝山钢铁股份有限公司 Hardened and tempered high-strength steel with yield strength of 1100MPa and production method thereof
CN111748730A (en) * 2019-03-28 2020-10-09 宝山钢铁股份有限公司 900 MPa-grade high-toughness high-magnetism hot-rolled magnetic yoke steel and production method thereof
CN111748732A (en) * 2019-03-28 2020-10-09 宝山钢铁股份有限公司 1000 MPa-grade high-toughness high-magnetism hot-rolled magnetic yoke steel and production method thereof
CN116145023A (en) * 2021-11-23 2023-05-23 中国石油天然气集团有限公司 A high-strength, high-toughness, high-collapse-resistant casing and its processing method

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06122936A (en) * 1992-10-12 1994-05-06 Nkk Corp Ultra-high-strength thin steel sheet excellent in hydrogen-delayed cracking resistance and manufacturing method thereof
CN101613831A (en) * 2008-06-27 2009-12-30 宝山钢铁股份有限公司 Non-modified high-hardness hot rolled steel and manufacture method and application
CN104513936A (en) * 2014-12-19 2015-04-15 宝山钢铁股份有限公司 Hardened and tempered high-strength steel with yield strength of 1100MPa and production method thereof
CN111748730A (en) * 2019-03-28 2020-10-09 宝山钢铁股份有限公司 900 MPa-grade high-toughness high-magnetism hot-rolled magnetic yoke steel and production method thereof
CN111748732A (en) * 2019-03-28 2020-10-09 宝山钢铁股份有限公司 1000 MPa-grade high-toughness high-magnetism hot-rolled magnetic yoke steel and production method thereof
CN116145023A (en) * 2021-11-23 2023-05-23 中国石油天然气集团有限公司 A high-strength, high-toughness, high-collapse-resistant casing and its processing method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120738568A (en) * 2025-09-05 2025-10-03 鞍钢股份有限公司 800 MPa-level steel plate for marine environment ore conveying pipeline and production method thereof

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