WO2023185754A1 - 高冷弯性能高强度热冲压部件及其制造方法 - Google Patents

高冷弯性能高强度热冲压部件及其制造方法 Download PDF

Info

Publication number
WO2023185754A1
WO2023185754A1 PCT/CN2023/084138 CN2023084138W WO2023185754A1 WO 2023185754 A1 WO2023185754 A1 WO 2023185754A1 CN 2023084138 W CN2023084138 W CN 2023084138W WO 2023185754 A1 WO2023185754 A1 WO 2023185754A1
Authority
WO
WIPO (PCT)
Prior art keywords
hot stamping
component
strength
heat treatment
parts
Prior art date
Application number
PCT/CN2023/084138
Other languages
English (en)
French (fr)
Inventor
谭宁
刘浩
金鑫焱
马雪丹
Original Assignee
宝山钢铁股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宝山钢铁股份有限公司 filed Critical 宝山钢铁股份有限公司
Publication of WO2023185754A1 publication Critical patent/WO2023185754A1/zh

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/02—Stamping using rigid devices or tools
    • B21D22/022—Stamping using rigid devices or tools by heating the blank or stamping associated with heat treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/02—Stamping using rigid devices or tools
    • 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
    • C21D11/00—Process control or regulation for heat treatments
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
    • 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
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • 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
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • 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
    • C22C38/40—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
    • C22C38/48—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
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/12—Aluminium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite

Definitions

  • the present invention relates to a manufacturing method of high-strength components, and in particular to a high-cold-bending performance and high-strength hot stamping component and a manufacturing method thereof.
  • Hot stamping steel is currently often used to prepare automobile structural parts and safety parts. Hot stamping steel can not only achieve vehicle lightweighting but also improve vehicle safety performance. Among them, 1500MPa hot stamping steel has been widely used in the automotive industry, and 1800MPa and 2000MPa hot stamping steel have also begun to be used.
  • the publication number is CN106399837A, and the publication date is February 15, 2017.
  • the Chinese patent document titled "Steel Materials for Hot Stamping, Hot Stamping Process and Hot Stamping Components” discloses a fine-grained hot stamping steel.
  • This technical solution mainly obtains steel materials with fine grains for hot stamping forming by adding V elements to the matrix, and also discloses the hot stamping process.
  • the surface temperature of the mold needs to be controlled below 200°C, and the cooling rate of the steel in the mold needs to be controlled to not be less than 10°C/s.
  • the publication number is CN111876676A, and the publication date is November 3, 2020.
  • the Chinese patent document titled "A production method of cold-rolled steel for 1800MPa-level hot stamping” discloses a production method of cold-rolled steel for 1800MPa-level hot stamping. Method, this technical solution obtains a 1800MPa grade hot stamping steel under the premise of keeping the cost low and without adding any trace elements. However, the toughness of the hot stamping steel, especially the cold bending performance, is insufficient.
  • the publication number is CN101583486A, the publication date is November 18, 2009, and the name is "coated steel strip, its preparation method, its use method, stamping blank prepared therefrom, stamping products prepared therefrom and containing such
  • the Chinese patent document "Products of Stamping Products” reports a hot stamping method for coated steel, which limits the elapsed time from the blank leaving the heat treatment furnace to the start of stamping to no more than 10 seconds, and controls the cooling rate of the blank from leaving the furnace to 400°C. Greater than 50°C/s, but this technical solution has not studied the toughness of the material.
  • the publication number is CN108588612A, and the publication date is September 28, 2018.
  • the Chinese patent document titled "Hot Stamping Forming Components, Pre-coated Steel Plate for Hot Stamping Forming and Hot Stamping Forming Process” discloses a pre-coated hot stamping forming process. Stamped steel and hot stamping methods. This technical solution mentions the problem of low cold bending performance in the patent CN101583486B when the temperature of the steel plate is transferred to the mold when the temperature is above 550°C. This patent improves the cold bending problem by reducing the thickness of the coating.
  • One of the objects of the present invention is to provide a method for producing high-strength hot stamping parts with high cold bending performance.
  • the method is simple and feasible, and can effectively produce high-strength hot stamping parts with high cold bending performance and has good Promotion prospects and application effects.
  • the present invention proposes a method for producing high-strength hot stamping parts with high cold bending performance, which includes the steps:
  • Stamping post-processing The parts are insulated and homogenized, and then machined to obtain the finished product.
  • the inventor has optimized the design of the heat treatment, transfer and stamping process of the components in step (3).
  • Heat treatment, transfer and stamping are particularly important to the performance of the components of the present invention.
  • the three are complementary to each other.
  • Heat treatment The process is very important for the forming of the parts, the transfer is very important for the cold bending and strength of the parts, and the stamping is very important for the forming and strength of the parts.
  • the temperature and time of the heat treatment process can be flexibly adjusted according to the thickness specification and size of the component.
  • the main purpose is to ensure complete austenitization and surface characteristics.
  • the optimally designed transfer process is the core of the technical solution of the present invention.
  • the transfer process was required to be as fast as possible, and it was basically completed within 10 seconds.
  • the research of the present invention found that combined with the hot stamping steel plate The phase transition temperature turning point of the substrate can control the transfer time within an appropriate range, thereby ensuring high strength and improving cold bending performance.
  • the heat treatment temperature can be in different temperature sections in stages within the above-mentioned temperature range of 750 to 960°C, or it can be only one stage temperature range.
  • the heat treatment temperature can be freely raised or lowered or
  • the total heat treatment time needs to be controlled between 1.5 and 10 minutes, and the heat treatment temperature should be controlled above 880°C for no less than 1.2 minutes.
  • the temperature of the semi-finished product leaving the heat treatment furnace should be ⁇ 900°C (such as between 900 and 960°C) , otherwise it may lead to incomplete austenitization and affect the strong plastic product.
  • the heat treatment time represents the sum of the times at all heat treatment temperatures.
  • the stamping post-processing process can further eliminate the residual stress in the forming process and solve the problems of uneven structure and hydrogen diffusion, thereby further improving the cold bending performance of the component.
  • the manufacturing of step (1) can be a conventional manufacturing method in this field, for example, including manufacturing the substrate strip through steelmaking, hot rolling, cold rolling, annealing and other processes according to the required elements.
  • Produced base plate steel strip It can be used directly as a steel plate for hot stamping, or it can be further plated on the base strip and then used as a steel plate for hot stamping.
  • the coating may be aluminum-silicon coating, aluminum-silicon-zinc-magnesium coating, aluminum-silicon-magnesium coating, zinc coating or zinc-iron alloy coating.
  • the steel plate coated with the above-mentioned various types of coatings on the surface of the base strip can be formed using methods well known in the art.
  • the substrate strip steel is immersed in a plating solution containing 7-10% Si, 2-4% Fe, the balance Al and inevitable impurities at 630-680°C to prepare a surface with aluminum Silicon coated steel plate.
  • the substrate strip steel is immersed in a plating solution containing 8-12% Zn, 2-4% Fe and the balance Al and inevitable impurities at 420-700°C to prepare a zinc-iron alloy coating on the surface. steel plate.
  • the substrate strip steel is immersed in a plating solution containing 6-10% Si, 0.5-3% Mg and the balance Al and inevitable impurities at 630-700°C to prepare a surface with aluminum, silicon and magnesium. Coated steel plate.
  • the substrate strip steel is immersed in a plating solution containing 0.08-0.3% Al by mass and the balance Zn and inevitable impurities at 420-700°C to prepare a steel plate with a zinc coating on the surface.
  • the substrate strip steel is immersed in a plating solution containing 6 to 10% Si, 0.5 to 2% Mg, 8 to 12% Zn, the balance of Al and inevitable impurities at 420 to 700°C.
  • a steel plate with an aluminum-silicon-zinc-magnesium coating on the surface was prepared.
  • the component preprocessing in step (2) is to process the component into a required shape.
  • the component can be processed into the required shape through one or more steps of laser or shearing, or by combining two or more steel plates of different shapes and thicknesses through tailor welding, patch welding, etc. Shape, complete component preprocessing.
  • the component preprocessing process described in the present invention is not limited to the operations stated, and may also include similar or equivalent operations in some other embodiments.
  • step (2) is a tailor-welded component or a patch-welded component, and if the thickness of one is below 1.5mm and the thickness of the other is above 1.5mm, the transfer time of the component will take two days. Both can be considered, for example, you can choose 13 ⁇ 20s.
  • the steel plates for hot stamping include: uncoated steel plates, aluminum-silicon coated steel plates, aluminum-silicon-zinc-magnesium coated steel plates, At least one of aluminum-silicon-magnesium coated steel sheets, hot-dip galvanized steel sheets, and zinc-iron alloy coated steel sheets.
  • the weight percentage of the chemical composition of the base plate of the hot stamping steel plate is: C: 0.2 to 0.4%, Mn: 1.0 ⁇ 2.0%, Si: 0.1 ⁇ 0.5%, Al: 0.01 ⁇ 0.1%, Ti: 0.01 ⁇ 0.1%, B: 0.0005 ⁇ 0.01%, Cr: 0.1 ⁇ 0.5%, and Nb+Mo+Ni: 0.3 ⁇ 0.6%, of which the mass percentage of any one of Nb, Mo, and Ni does not exceed 0.3%.
  • the C element content in steel should not be too low.
  • the C element content in steel is less than 0.2%, the strength cannot be guaranteed.
  • the C element content in steel should not be too high.
  • the mass percentage content of the C element is controlled between 0.2-0.4%.
  • the Al element is also a deoxidizer, and adding an appropriate amount of Al element can also improve the impact toughness of the steel. Therefore, considering the influence of Al element on the properties of steel, in the substrate of the present invention, the mass percentage content of Al element is controlled between 0.01% and 0.1%.
  • B In the substrate of the present invention, adding an appropriate amount of B element can improve the hardenability of the steel to ensure that all positions of the hot stamping parts are fully hardenable. Therefore, in the substrate of the present invention, the mass percentage of B element is controlled between 0.0005% and 0.01%.
  • Ti is a C, N strengthening element. Adding an appropriate amount of Ti element to the steel can improve the strength and toughness of the substrate, thereby further improving the strength and toughness of hot stamping parts. At the same time, the Ti element can also interact with the B element to better utilize the hardenability of B. Based on this, in order to exert the beneficial effects of Ti element, the mass percentage content of Ti element in the substrate of the present invention is controlled between 0.01% and 0.1%.
  • adding an appropriate amount of Cr element can also improve the hardenability of the steel and ensure that all positions of the hot stamping parts are fully quenched. Therefore, in the substrate of the present invention, the mass percentage of Cr element is controlled between 0.1% and 0.5%.
  • Nb, Mo, and Ni elements are further added.
  • Nb and Mo elements can refine the grains and improve the toughness of the parts after hot stamping.
  • the Ni element can also play a role in improving the toughness of hot stamping parts, and Ni can improve hydrogen diffusion. Therefore, in the substrate of the present invention, the mass percentage contents of Nb, Mo, and Ni elements are controlled to satisfy: Nb+Mo+Ni: 0.3-0.6%.
  • the mass percentage of any one of Nb, Mo and Ni does not exceed 0.3%.
  • the mass percentage content of Nb is 0.0001% to 0.25%.
  • the mass percentage content of Mo is 0.1% to 0.25%.
  • the mass percentage content of Ni is 0.05% to 0.25%, such as 0.08% to 0.2%.
  • step (3) the total time of the heat treatment is controlled to be 1.5 to 8 minutes.
  • step (3) the stamping speed is controlled to 40-80 mm/s and maintained for 2-30 s.
  • the mold temperature is always lower than 200°C. In some embodiments, the mold temperature ranges from 25 to 190°C during impact.
  • step (4) the temperature of insulation and homogenization is 150-250°C, and the time is 10-30 minutes. .
  • the mechanical processing includes at least one of cutting, trimming, punching, and welding. one.
  • the parts form a martensite structure with a volume ratio of more than 95% in step (3).
  • the method of the present invention can be used to prepare high cold-bending performance and high-strength hot stamping parts with a strong plastic area of ⁇ 10 GPa ⁇ % and a cold bending angle of ⁇ 60 degrees.
  • the maximum load of the three-point bending of the high-strength hot stamping parts is ⁇ 13KN.
  • the high-strength hot stamping parts prepared by the method of the present invention have a tensile strength of ⁇ 1500MPa and an elongation after break of ⁇ 5.5%.
  • the tensile strength of the high-strength hot stamping parts prepared by the method of the present invention is between 1500 and 1700 MPa, the elongation after break is between 6.0 and 7.0%, and the strong plastic volume is ⁇ 10 GPa ⁇ %. In some embodiments, the tensile strength of the high-strength hot stamping parts prepared by the method of the present invention is between 1800 and 2100 MPa, the elongation after break is between 5.5 and 6.0%, and the strong plastic volume is ⁇ 10.5GPa ⁇ %. .
  • another object of the present invention is to provide a high-strength hot stamping part, which
  • the parts not only have high strength, but also have high cold bending performance. They have wide applicability and can be effectively used in the automotive industry. They show good resistance to frontal collisions and side collisions during automobile collisions.
  • the present invention proposes a high-strength hot stamping component with a strong plastic volume ⁇ 10 GPa ⁇ % and a cold bending angle ⁇ 60 degrees.
  • the maximum three-point bending load of the high-strength hot stamping component is ⁇ 13KN.
  • the high-strength hot stamping parts of the present invention have a strong plastic product between 10-12GPa ⁇ %, a cold bending angle between 60-75 degrees, and a maximum load of three-point bending between 13-20KN.
  • the diffusible hydrogen content of the high-strength hot stamped parts of the present invention is between 0.01-0.06 ppm.
  • the method for producing high-strength hot stamping parts with high cold bending performance and hot stamping parts according to the present invention have the following advantages and beneficial effects:
  • the inventor has carried out a reasonable optimized design for the manufacturing method of high-strength hot stamping parts. Through the optimized control of the three processes of heat treatment, transfer and stamping, it can ensure that the parts can obtain higher strength while also achieving high strength. Has good toughness and cold bending properties.
  • the parts can form more than 95% martensite structure during the heat treatment and stamping processes, so that they can have high strength.
  • the present invention makes full use of the difference in cooling between the surface layer and the core to form a gradient tissue transformation control on the surface layer of the component, which is very helpful in improving the toughness and cold bending performance of the component. effect.
  • the performance of the high-strength hot stamping parts prepared by the above method of the present invention is quite excellent, with a strong plastic volume ⁇ 10 GPa ⁇ %, a cold bending angle ⁇ 60 degrees, and preferably a maximum load of three-point bending ⁇ 13 KN.
  • the application of this high-strength hot stamping part is It has a wide range of properties and can be effectively used in the automotive industry. It shows good resistance to frontal collisions and side collisions during automobile collisions.
  • Figure 1 is a photo of the coating cross-section microstructure of the high-strength hot stamping component of Example 2.
  • Table 1 lists the mass percentage ratio of each chemical element in the substrate of the hot stamping steel plate of Examples 1-9 and the relationship between the various chemical elements.
  • the high-strength hot stamping parts of Examples 1-9 are all produced by the following steps:
  • a substrate strip steel is manufactured through steelmaking, hot rolling, cold rolling, annealing and other processes.
  • the prepared base strip steel can be directly used as a steel plate for hot stamping, or the base strip steel can be further plated and then used as a steel plate for hot stamping.
  • blanking can be completed through one or more steps of laser or shearing, or two or more steel plates of different shapes and thicknesses can be made through tailor welding, patch welding, etc. The combination is complete.
  • the mold temperature always lower than 200°C; when the steel plate thickness of the manufactured parts is ⁇ 1.5mm, the controlled transfer time is 11-20s, and when the steel plate thickness of the manufactured parts is >1.5mm, the controlled transfer time is 13-25s.
  • Stamping post-processing Insulate and homogenize the parts, control the temperature of the insulation and homogenization to 150 ⁇ 250°C, and the time is 10 ⁇ 30 minutes, and then perform mechanical processing to obtain the finished product; among them, mechanical processing includes cutting, Trimming, punching, welding.
  • the hot stamped steel plate may be an uncoated steel plate or a coated steel plate.
  • the hot-stamped steel plate is a coated steel plate, it may specifically be: aluminum-silicon coated steel plate, aluminum-silicon-zinc-magnesium coated steel plate, aluminum-silicon-magnesium coated steel plate, hot-dip galvanized coated steel plate, zinc-iron alloy coated steel plate.
  • Example 1 According to the mass percentage of each chemical element shown in Table 1 above, a 1.2mm base plate strip was obtained through steelmaking, hot rolling, cold rolling, and annealing. The 1.2mm substrate strip is hot-dip aluminum-silicon plated at 650°C to obtain an aluminum-silicon coated steel plate. The composition of the plating solution is 9% Si, 2.3% Fe, and the rest is Al and unavoidable impurities. In component preprocessing, aluminum-silicon coated steel plates are continuously blanked into parts of a certain shape.
  • Example 2 According to the mass percentage ratio of each chemical element shown in Table 1 above, through steelmaking, hot rolling, cold rolling, and annealing, 1.5 mm and 1.8 mm base plate strip steel was obtained.
  • the 1.5mm and 1.8mm substrate strips are hot-dip aluminum-silicon plated at 650°C to obtain an aluminum-silicon coated steel plate.
  • the composition of the plating solution is 9% Si, 2.3% Fe, and the rest is Al and unavoidable impurities.
  • component preprocessing aluminum-silicon coated steel plates are laser blanked into parts of a certain shape, and the two parts are connected by tailor welding to obtain parts of a certain shape.
  • Example 3 According to the mass percentage of each chemical element shown in Table 1 above, steelmaking, hot rolling, cold rolling, and annealing were performed to obtain a 1.8 mm base plate strip.
  • the 1.8mm substrate strip is hot-dip aluminum-silicon plated at 660°C to obtain an aluminum-silicon coated steel plate.
  • the composition of the plating solution is 8.5% Si, 2.5% Fe, and the rest is Al and unavoidable impurities.
  • the aluminum-silicon coated steel plate is continuously blanked into a billet of a certain shape, and local parts of the billet are patched by spot welding (patch welding is performed from two substrates with a thickness of 1.8mm) to obtain parts of a certain shape. .
  • Example 4 According to the mass percentage of each chemical element shown in Table 1 above, steelmaking, hot rolling, cold rolling, and annealing were performed to obtain a 2.0 mm base plate strip steel, which was used as a steel plate for hot stamping. In component preprocessing, strip steel is continuously blanked into a certain shape of blank.
  • Example 5 According to the mass percentage of each chemical element shown in Table 1 above, steelmaking, hot rolling, cold rolling, and annealing were performed to obtain a 2.3mm base plate strip, which was used as a steel plate for hot stamping. In component preprocessing, strip steel is continuously blanked into a certain shape of blank.
  • Example 6 According to the mass percentage of each chemical element shown in Table 1 above, steelmaking, hot rolling, cold rolling, and annealing were performed to obtain a 1.4 mm base plate strip.
  • the 1.4mm base plate strip is hot-dip galvanized and alloyed at 680°C to obtain a zinc-iron alloy coated steel plate.
  • the composition of the plating solution is 9% Zn, 2.3% Fe, and the rest is Al and unavoidable impurities.
  • the zinc-iron alloy coated steel plate is laser blanked into a billet of a certain shape.
  • Example 7 According to the mass percentage of each chemical element shown in Table 1 above, steelmaking, hot rolling, cold rolling, and annealing were performed to obtain a 2.5 mm base plate strip.
  • the 2.5mm substrate strip is hot-dip aluminum-silicon-magnesium coating at 680°C to obtain an aluminum-silicon-magnesium coated steel plate.
  • the composition of the plating solution is 8.5% Si, 1% Mg, and the rest is Al and unavoidable impurities.
  • aluminum-silicon-magnesium coated steel plates are laser blanked into billets of a certain shape.
  • Example 8 According to the mass percentage of each chemical element shown in Table 1 above, a 0.9mm base plate strip was obtained through steelmaking, hot rolling, cold rolling, and annealing. The 0.9mm base plate strip is hot-dipped at 680°C to obtain a hot-dip galvanized steel plate. The composition of the plating solution is 0.13% Al, and the rest is Zn and unavoidable impurities. In component preprocessing, hot-dip galvanized steel sheets are laser blanked into blanks of a certain shape.
  • Example 9 According to the mass percentage of each chemical element shown in Table 1 above, a 3.0 mm base plate strip steel was obtained through steelmaking, hot rolling, cold rolling, and annealing. The 3.0mm substrate strip is hot-plated at 680°C to obtain an aluminum-silicon-zinc-magnesium coated steel plate. The composition of the plating solution is 8.5% Si, 1% Mg, 10% Zn, and the rest is Al and unavoidable impurities. In component preprocessing, the aluminum-silicon-zinc-magnesium coated steel plate is laser blanked into a billet of a certain shape, and the billet is heat treated.
  • Table 2-1 and Table 2-2 list the relevant process parameters of the manufacturing method of the high-strength hot stamping parts of Embodiment 1-9.
  • Embodiment 1-9 when Embodiment 1-9 is performing the above-mentioned manufacturing process, in step (3), after Embodiment 1-9 undergoes heat treatment, transfer and stamping of components according to design requirements, the Embodiment 1 can be -9 parts were sampled, and the microstructure of the parts of each example was tested to obtain the mentioned proportion of martensite structure in the parts of Examples 1-9.
  • the relevant test results are listed in Table 3 below. .
  • the percentage of martensite in the component is measured using the metallographic method: after the sample is mounted, it is mechanically ground, polished, and corroded, and then the collected images are processed using metallographic image analysis software to obtain the martensite. The percentage of tissue.
  • the performance detection means used are as follows:
  • the strong plastic product is a comprehensive performance index that characterizes the strength and toughness level of metal materials.
  • the present invention uses the product of the tensile strength of the component and the elongation after fracture to obtain the strong plastic product of the samples in each embodiment. According to the metal tensile test method GB/T228.1, the tensile strength and post-break elongation of the component are obtained through the tensile test.
  • Three-point bending test and drop weight test are to place the hot stamped parts of the embodiment on the bending device, adjust the span, and load the parts for bending tests until the parts break. Record the maximum load at which it breaks. Among them, in the drop weight test, a 30kg drop weight was dropped freely from a height of 50cm, and the cracking of the sample components of each example was observed.
  • Diffusive hydrogen content test Use wire cutting, punching or sawing with water cooling to obtain samples from the components, ultrasonically clean them with acetone, and use a hydrogen analyzer to measure the content of the samples in each example at 300 to 400°C. Diffusible hydrogen content.
  • Example 2 is a tailor-made weldment and Example 3 is a patch weldment, both of which involve welds
  • the drop weight test is not easy to evaluate due to the influence of the welds; at the same time, the maximum load test is affected by the welds. It’s also difficult to evaluate. Therefore, neither the three-point bending test nor the drop weight test was performed in Example 2 and Example 3.
  • the high-strength hot stamping parts of Examples 1-9 not only have higher strength, but also have better toughness and cold bending performance.
  • the high-strength hot stamping parts of Examples 1-9 have a strong plastic product between 10-12GPa ⁇ %, a cold bending angle between 60-75 degrees, and a maximum load of three-point bending between 13-20KN. between.
  • Figure 1 is a photo of the coating cross-section microstructure of the high-strength hot stamping component of Example 2.
  • Example 2 has an aluminum-silicon coating, which includes a substrate A and a coating B. Among them, there is an obvious interface layer C between the coating layer A and the substrate B.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Heat Treatment Of Articles (AREA)

Abstract

本发明公开了一种高冷弯性能的高强度热冲压部件及其制造方法，该方法包括步骤：(1)制造热冲压用钢板；(2)部件预加工；(3)部件热处理、转移及冲压：将部件半成品放入热处理炉，控制热处理温度为750～960℃，控制热处理的总时间为1.5～10min，热处理温度在880℃以上的时间不低于1.2min；将完成热处理的半成品转移至模具中进行合模冲压，该半成品离开热处理炉的温度不低于900℃；当制得部件的钢板厚度≤1.5mm时，控制转移时间为11～20s，当制得部件的钢板厚度＞1.5mm时，控制转移时间为13～25s；(4)冲压后处理：对部件进行保温均质化，然后进行机械加工以获得成品。相应地，采用上述方法可以制备一种强塑积≥10GPa·％，冷弯角≥60度，三点弯最大载荷≥13KN的部件。

Description

高冷弯性能高强度热冲压部件及其制造方法 技术领域
本发明涉及一种高强度部件的制造方法，尤其涉及一种高冷弯性能高强度热冲压部件及其制造方法。
背景技术
近年来，随着汽车行业的迅速发展，市场和用户对于车辆的要求也越来越高，轻量化已经逐渐成为了未来汽车行业的发展趋势。
为了满足车辆轻量化的要求，当前常采用热冲压钢来制备汽车结构件和安全件，热冲压钢既能够实现车辆的轻量化又能提升车辆的安全性能。其中，1500MPA级别的热冲压钢已经在汽车行业得到了大规模的应用，1800MPa和2000MPa的热冲压钢也相继开始使用。
然而，研究发现，具有全马氏体组织的热冲压钢的强度越高，会导致钢材的韧性下降，其在碰撞过程中发生脆断和服役过程中延迟开裂的风险也会增加。这一问题直接导致了当前热冲压钢很难兼具较高的强度以及较优的韧性。
为了解决这一问题，近年来，大量的科技工作者做了很多有益的尝试：
公开号为CN110799659A，公开日为2020年2月14日，名称为“用于生产具有改善的延性的高强度钢部件的方法以及通过所述方法获得的部件”的中国专利文献公开了一种用于生产改善的延性的高强度钢部件及其方法，其主要通过控制Ni含量及其分布，并控制基体中Ni含量高于0.25％，来获得具有良好延展性的高强度钢部件。
公开号为CN106399837A，公开日为2017年2月15日，名称为“热冲压成形用钢材、热冲压成形工艺及热冲压成形构件”的中国专利文献公开了一种细晶粒的热冲压钢。该技术方案主要通过向基体中添加V元素，来获得具有细晶粒的热冲压成形用钢材，其同时公开了热冲压过程。在该技术方案的热冲压过程中，需要控制模具表面温度在200℃以下，并控制钢材在模具中的冷速不少于10℃/s。
公开号为CN111876676A，公开日为2020年11月03日，名称为“一种1800MPa级热冲压成形用冷轧钢生产方法”的中国专利文献公开了一种1800MPa级热冲压成形用冷轧钢生产方法，该技术方案在控制成本较低且不添加任何微量元素的前提下，获得了一种1800MPa级的热冲压成形钢，但该热冲压成形钢的韧性，尤其是冷弯性能是不足的。
公开号为CN101583486A，公开日为2009年11月18日，名称为“涂覆的钢带材、其制备方法、其使用方法、由其制备的冲压坯料、由其制备的冲压产品和含有这样的冲压产品的制品”的中国专利文献报道了一种涂覆钢材的热冲压方法，其限定坯料离开热处理炉到冲压开始的经历时间不多于10s，并控制坯料从离开炉至400℃的冷速大于50℃/s，但该技术方案对于材料的韧性并没有进行研究。
公开号为CN108588612A，公开日为2018年9月28日，名称为“热冲压成形构件、热冲压成形用预涂镀钢板及热冲压成形工艺”的中国专利文献公开了一种预涂镀的热冲压钢及其热冲压方法。在该技术方案中提到了在钢板移送至模具时温度在550℃以上，专利CN101583486B存在的冷弯性能较低的问题，该专利通过降低镀层厚度来改善冷弯问题。
由此可见，在当前现有技术中，本领域技术人员对于具有良好冷弯性能的高强度热冲压成形钢研究较少。在上述技术方案中，有且仅有公开号为CN110799659A的专利文献在保证热冲压成形钢在具备高强度的同时，研究了材料的冷弯性能。
有研究发现，热冲压成形钢的冷弯角越大，在同等条件下能吸收更多的能量，能够推迟断裂失效时间。因此，发明人认为研究高强度热冲压钢的冷弯性能及其可行的生产方法尤为重要，基于此，本发明期望获得一种用于生产高冷弯性能的高强度热冲压部件的方法。
发明内容
本发明的目的之一在于提供一种用于生产高冷弯性能的高强度热冲压部件的方法，该方法简便可行，其可以有效生产具有高冷弯性能的高强度热冲压部件，具有良好的推广前景和应用效果。
为了实现上述目的，本发明提出了一种用于生产高冷弯性能的高强度热冲压部件的方法，其包括步骤：
(1)制造热冲压用钢板；
(2)部件预加工；
(3)部件热处理、转移及冲压：将加工成指定形状的部件半成品放入热处理炉，控制热处理温度为750～960℃，控制热处理的总时间为1.5～10min，其中热处理温度在880℃以上的时间不低于1.2min；将完成热处理的半成品转移至模具中进行合模冲压，该半成品离开热处理炉的温度≥900℃；其中当制得部件的钢板厚度≤1.5mm时，控制转移时间为11～20s，当制得部件的钢板厚度＞1.5mm时，控制转移时间为13～25s；
(4)冲压后处理：对部件进行保温均质化，然后进行机械加工以获得成品。
在本发明上述技术方案中，发明人对步骤(3)的部件热处理、转移及冲压过程进行了优化设计，热处理、转移、冲压对本发明所述部件的性能尤其重要，三者是相辅相成的，热处理工艺对部件的成形非常关键，转移对部件的冷弯和强度非常关键，冲压对部件的成形和强度非常重要。
其中，热处理工艺的温度以及时间可以根据部件的厚度规格和大小灵活调整，其目的主要是为了保证完全的奥氏体化和表面特征。优化设计的转移工艺是本发明技术方案的核心，以往热成形部件为了保证高强度，都要求转移过程越快越好，基本都在10s内完成，但本发明研究发现，结合热冲压用钢板的基板的相变温度转折点，可以将转移时间控制在合适的范围内，从而既可以保证高强度，又可以改善冷弯性能。
在本发明中，在具体实施时，热处理温度在上述750～960℃温度范围内可以是分阶段呈现不同的温度段，也可以仅是一个阶段温度范围，热处理温度可以是自由升高或者降低或其组合，热处理的总时间需控制在1.5～10min之间，并控制热处理温度在880℃以上的时间不低于1.2min，半成品离开热处理炉的温度≥900℃(如900～960℃之间)，否则可能会导致奥氏体化不彻底，影响强塑积。其中，热处理时间表示的是所有热处理温度下的时间总和。
相应地，在本发明所述的步骤(4)中，冲压后处理工艺可以进一步消除成形过程的残余应力，解决组织不均匀、氢扩散的问题，从而进一步提升部件的冷弯性能。
本发明中，步骤(1)的制造可以是本领域常规的制造方法，例如包括按照所需的元素通过炼钢、热轧、冷轧、退火等工序，制造得到基板带钢。制得的基板带钢 可以直接作为热冲压用钢板，也可以进一步对基板带钢进行镀覆镀层再作为热冲压用钢板。镀层可以是铝硅镀层、铝硅锌镁镀层、铝硅镁镀层、锌镀层或锌铁合金镀层。可采用本领域周知的方法形成在基板带钢表面镀覆有上述各类镀层的钢板。
例如，在630～680℃下将基板带钢浸入含有质量百分比为7～10％的Si、2～4％的Fe和余量的Al和不可避免的杂质的镀液中，制备得到表面具有铝硅镀层的钢板。在420～700℃下将基板带钢浸入含有质量百分比为8～12％的Zn、2～4％的Fe和余量的Al和不可避免的杂质的镀液中，制备得到表面具有锌铁合金镀层的钢板。在630～700℃下将基板带钢浸入含有质量百分比为6～10％的Si、0.5～3％的Mg和余量的Al和不可避免的杂质的镀液中，制备得到表面具有铝硅镁镀层的钢板。在420～700℃下将基板带钢浸入含有质量百分比为0.08～0.3％的Al和余量的Zn和不可避免的杂质的镀液中，制备得到表面具有锌镀层的钢板。在420～700℃下将基板带钢浸入含有质量百分比为6～10％的Si、0.5～2％的Mg、8～12％的Zn和余量的Al和不可避免的杂质的镀液中，制备得到表面具有铝硅锌镁镀层的钢板。
本发明中，步骤(2)所述部件预加工为将部件加工成所需的形状。根据所需部件形状，可以通过一步或者多步激光或剪切，也可以通过拼焊、补丁焊等形式将不同形状、不同厚度的两块或多块钢板组合等方式将部件加工成所需的形状，完成部件预加工。当然，本发明所述的部件预加工工艺并不限于所陈述的操作，在一些其他的实施方式中，还可以包含类似或等同的操作。
此外，需要注意的是，如果在步骤(2)中获得的是拼焊部件或者补丁焊部件，且如果一个厚度是1.5mm以下，另一个厚度是1.5mm以上，则该部件的转移时间需两者都兼顾，例如可以选择13～20s。
进一步地，在本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法中，所述热冲压用钢板包括：无镀层钢板、铝硅镀层钢板、铝硅锌镁镀层钢板、铝硅镁镀层钢板、热镀锌镀层钢板、锌铁合金镀层钢板的至少其中之一。
进一步地，在本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法中，所述热冲压用钢板的基板的化学成分重量百分配比为：C：0.2～0.4％，Mn：1.0～2.0％，Si：0.1～0.5％，Al：0.01～0.1％，Ti：0.01～0.1％，B：0.0005～0.01％，Cr：0.1～0.5％，以及Nb+Mo+Ni：0.3～0.6％，其中Nb，Mo，Ni中的任何一种的质量百分含量不超过0.3％。
在本发明所述的热冲压用钢板的基板中，各化学元素的设计原理如下所述：
C：在本发明所述的基板中，基板中添加适量的C元素可以确保钢材的强度，以保证热冲压部件的强度。由此，钢中C元素含量不宜过低，当钢中C元素含量低于0.2％时，则强度不能保证；同时，钢中C元素含量也不宜过高，当钢中C元素含量高于0.4％时，则会导致强度过高，使钢材的焊接性能变差。基于此，考虑到基板的性能，在本发明所述的基板中，将C元素的质量百分含量控制在0.2-0.4％之间。
Mn：在本发明所述的基板中，Mn元素和C元素一样，其也是为了保证热冲压部件的强度而加入，同时Mn元素还可以进一步弥补基板钢材的韧性。当钢中Mn元素含量低于1.0％时，则不能保证钢材的强度；当钢中Mn元素含量高于2.0％时，元素偏析和生产成本都会增加。基于此，为了发挥Mn元素的有益效果，在本发明所述的基板中，将Mn元素的质量百分含量控制在1.0％-2.0％之间。
Si：在本发明所述的基板中，添加适量的Si元素不仅可以提高热冲压部件的强度，其同时也是炼钢过程中重要的脱氧剂。当钢中Si元素含量过高时，会导致生产过程中氧化严重，难以保证好的产品表面质量。因此，在本发明所述的基板中，将Si元素的质量百分含量控制在0.1～0.5％之间。
Al：在本发明所述的基板中，Al元素也是脱氧剂，添加适量的Al元素还可以提高钢材的冲击韧性。由此，考虑到Al元素对钢材性能的影响，在本发明所述的基板中，将Al元素的质量百分含量控制在0.01～0.1％之间。
B：在本发明所述的基板中，添加适量的B元素，可以提高钢材的淬透性，以保证热冲压部件各位置充分淬透。因此，在本发明所述的基板中，将B元素的质量百分含量控制在0.0005～0.01％之间。
Ti：在本发明所述的基板中，Ti是C，N强化元素，钢中添加适量的Ti元素可以提高基板的强度以及韧性，进而进一步提高热冲压部件的强度和韧性。同时，Ti元素还能够跟B元素相互作用，从而更好发挥B的淬透性。基于此，为了发挥Ti元素的有益效果，在本发明所述的基板中，将Ti元素的质量百分含量控制在0.01～0.1％之间。
Cr：在本发明所述的基板中，添加适量的Cr元素，也可以提高钢材的淬透性，保证热冲压部件各位置充分淬透。因此，在本发明所述的基板中，将Cr元素的质量百分含量控制在0.1～0.5％之间。
需要说明的是，在本发明所述的基板中，还进一步地添加有适量的Nb，Mo，Ni元素，其中，Nb，Mo元素均可以起到细化晶粒，提高热冲压后部件韧性的作用；而Ni元素也可以起到改善热冲压部件韧性的作用，同时Ni对氢扩散有改善。由此，在本发明所述的基板中，控制Nb，Mo，Ni元素的质量百分含量满足：Nb+Mo+Ni：0.3～0.6％。其中Nb，Mo，Ni中的任何一种的质量百分含量不超过0.3％。在一些实施方案中，Nb的质量百分比含量为0.0001％～0.25％。在一些实施方案中，Mo的质量百分比含量为0.1％～0.25％。在一些实施方案中，Ni的质量百分比含量为0.05％～0.25％，如0.08％～0.2％。
进一步地，在本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法中，在步骤(3)中，控制热处理的总时间为1.5～8min。
进一步地，在本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法中，在步骤(3)中，控制冲压速度为40～80mm/s，并保持2～30s。
进一步地，在本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法中，在步骤(3)中，冲压过程中，模具温度始终低于200℃。在一些实施方案中，冲击过程中，模具温度在25～190℃的范围内。
进一步地，在本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法中，在步骤(4)中，保温均质化的温度为150～250℃，时间为10～30min。
进一步地，在本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法中，在步骤(4)中，所述机械加工包括切割、修边、冲孔、焊接的至少其中之一。
进一步地，在本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法中，部件在步骤(3)中形成体积比例95％以上的马氏体组织。
采用本发明方法可以制备强塑积≥10GPa·％、冷弯角≥60度的高冷弯性能、高强度热冲压部件，优选地，该高强度热冲压部件的三点弯最大载荷≥13KN。在一些实施方案中，采用本发明方法制备得到的高强度热冲压部件的抗拉强度≥1500MPa，断后伸长率≥5.5％。在一些实施方案中，采用本发明方法制备得到的高强度热冲压部件的抗拉强度在1500～1700MPa之间，断后伸长率在6.0～7.0％之间，且强塑积≥10GPa·％。在一些实施方案中，采用本发明方法制备得到的高强度热冲压部件的抗拉强度在1800～2100MPa之间，断后伸长率在5.5～6.0％之间，且强塑积≥10.5GPa·％。
因此，本发明的另一目的在于提供一种高强度热冲压部件，该高强度热冲压部 件在具有较高强度的同时，还具有较高的冷弯性能，其适用性广泛，可以有效应用于汽车行业，在汽车碰撞过程中表现良好的抗正碰、侧碰性能。
为了实现上述目的，本发明提出了一种高强度热冲压部件，其强塑积≥10GPa·％，冷弯角≥60度。在一些实施方案中，所述高强度热冲压部件的三点弯最大载荷≥13KN。在一些实施方案中，本发明所述高强度热冲压部件的强塑积在10-12GPa·％之间，冷弯角在60-75度之间，三点弯最大载荷在13-20KN之间。在一些实施方案中，本发明所述高强度热冲压部件的扩散氢含量在0.01-0.06ppm之间。在一些实施方案中，所述高强度热冲压部件的抗拉强度≥1500MPa，断后伸长率≥5.5％。在一些实施方案中，所述高强度热冲压部件的抗拉强度在1500～1700MPa之间，断后伸长率在6.0～7.0％之间，且强塑积≥10GPa·％。在一些实施方案中，所述高强度热冲压部件的抗拉强度在1800～2100MPa之间，断后伸长率在5.5～6.0％之间，且强塑积≥10.5GPa·％。在一些实施方案中，所述热冲压部件采用本发明任一实施方案所述的方法制得。
相较于现有技术，本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法、热冲压部件具有如下所述的优点以及有益效果：
在本发明中，发明人对高强度热冲压部件的制造方法进行了合理的优化设计，其通过对热处理、转移、冲压三个工艺的优化控制，可以确保部件在获得较高强度的同时，还具有良好的韧性和冷弯性能。
在本发明所述用于生产高冷弯性能的高强度热冲压部件的方法中，部件在热处理和冲压过程中能够形成95％以上的马氏体组织，从而能够具备高的强度。同时，部件在精确的转移控制中，本发明充分利用了表层和心部冷却的差异，在部件表层形成了梯度的组织转变控制，对部件的韧性、冷弯性能的提升起到很好的帮助作用。
采用本发明上述方法制备的高强度热冲压部件的性能相当优异，其强塑积≥10GPa·％，冷弯角≥60度，优选三点弯最大载荷≥13KN，该高强度热冲压部件的适用性十分广泛，其可以有效应用于汽车行业，在汽车碰撞过程中表现良好的抗正碰、侧碰性能。
附图说明
图1为实施例2的高强度热冲压部件的镀层截面微观结构照片。
具体实施方式
下面将结合具体的实施例对本发明所述的用于生产高冷弯性能的高强度热冲压部件的方法、热冲压部件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。
实施例1-9
表1列出了实施例1-9的热冲压用钢板的基板中各化学元素的质量百分配比及各种化学元素之间的关系。
表1(wt％，余量为Fe和其他不可避免的杂质)
在本发明中，实施例1-9的高强度热冲压部件均采用以下步骤制得：
(1)按照上述表1所示各化学元素的质量百分配比通过炼钢、热轧、冷轧，退火等工序，制造得到基板带钢。其中，制得的基板带钢可以直接作为热冲压用钢板，也可以进一步对基板带钢进行镀覆镀层再作为热冲压用钢板。
(2)部件预加工：根据所需部件形状，可以通过一步或者多步激光或剪切完成落料，也可以通过拼焊、补丁焊等形式将不同形状、不同厚度的两块或多块钢板组合完成。
(3)部件热处理、转移及冲压：将加工成指定形状的部件半成品放入热处理炉， 控制热处理温度为750～960℃，控制热处理的总时间为1.5～10min，并优选控制为1.5～8min，且热处理温度在880℃以上的时间不低于1.2min；将完成热处理的半成品转移至模具中进行合模冲压，该半成品离开热处理炉的温度不低于900℃；通过压机将上下模具合模，控制冲压速度为40～80mm/s，并保持2～30s，冲压过程中，模具温度始终低于200℃；其中当制得部件的钢板厚度≤1.5mm时，控制转移时间为11～20s，当制得部件的钢板厚度＞1.5mm时，控制转移时间为13～25s。
(4)冲压后处理：对部件进行保温均质化，控制保温均质化的温度为150～250℃，时间为10～30min，然后再进行机械加工以获得成品；其中，机械加工包括切割、修边、冲孔、焊接。
需要说明的是，在上述制造方法的步骤(1)中，热冲压钢板可以是无镀层钢板，也可以是镀层钢板。当热冲压钢板为镀层钢板时，其具体可以为：铝硅镀层钢板、铝硅锌镁镀层钢板、铝硅镁镀层钢板、热镀锌镀层钢板、锌铁合金镀层钢板。
在本发明中，实施例1-9在上述步骤(1)和步骤(2)中的具体工艺步骤如下所述：
实施例1：按照上述表1所示各化学元素的质量百分配比经过炼钢、热轧、冷轧，退火，获得1.2mm的基板带钢。将1.2mm基板带钢在650℃下进行热浸镀铝硅，以获得铝硅镀层钢板，其中，镀液成分为9％Si，2.3％Fe，其余为Al及不可避免杂质。在部件预加工中，铝硅镀层钢板连续落料成一定形状的部件。
实施例2：按照上述表1所示各化学元素的质量百分配比经过炼钢、热轧、冷轧，退火，获得1.5mm和1.8mm的基板带钢。将1.5mm和1.8mm的基板带钢在650℃下进行热浸镀铝硅，以获得铝硅镀层钢板，其中，镀液成分为9％Si，2.3％Fe，其余为Al及不可避免杂质。在部件预加工中，将铝硅镀层钢板激光落料成一定形状的部件，通过拼焊将两部件连接，以获得一定形状的部件。
实施例3：按照上述表1所示各化学元素的质量百分配比经过炼钢、热轧、冷轧，退火，获得1.8mm的基板带钢。将1.8mm基板带钢在660℃下进行热浸镀铝硅，以获得铝硅镀层钢板，其中，镀液成分为8.5％Si，2.5％Fe，其余为Al及不可避免杂质。在部件预加工中，将铝硅镀层钢板连续落料成一定形状的坯料，在坯料局部位置通过点焊进行打补丁(由两块厚度为1.8mm的基板进行补丁焊)，获得一定形状的部件。
实施例4：按照上述表1所示各化学元素的质量百分配比经过炼钢、热轧、冷轧，退火，获得2.0mm的基板带钢，并作为热冲压用钢板。在部件预加工中，将带钢连续落料成一定形状的坯料。
实施例5：按照上述表1所示各化学元素的质量百分配比经过炼钢、热轧、冷轧，退火，获得2.3mm的基板带钢，并作为热冲压用钢板。在部件预加工中，将带钢连续落料成一定形状的坯料。
实施例6：按照上述表1所示各化学元素的质量百分配比经过炼钢、热轧、冷轧，退火，获得1.4mm的基板带钢。将1.4mm的基板带钢在680℃下完成热镀锌及合金化过程，以获得锌铁合金镀层钢板，其中，镀液成分为9％Zn，2.3％Fe，其余为Al及不可避免杂质。在部件预加工中，将锌铁合金镀层钢板激光落料成一定形状的坯料。
实施例7：按照上述表1所示各化学元素的质量百分配比经过炼钢、热轧、冷轧，退火，获得2.5mm的基板带钢。将2.5mm的基板带钢在680℃下进行热镀铝硅镁镀层，以获得铝硅镁镀层钢板，其中，镀液成分为8.5％Si，1％Mg，其余为Al及不可避免杂质。在部件预加工中，将铝硅镁镀层钢板激光落料成一定形状的坯料。
实施例8：按照上述表1所示各化学元素的质量百分配比经过炼钢、热轧、冷轧，退火，获得0.9mm的基板带钢。将0.9mm的基板带钢在680℃下进行热镀，以获得热镀锌镀层钢板，其中，镀液成分为0.13％Al，其余为Zn及不可避免杂质。在部件预加工中，将热镀锌镀层钢板激光落料成一定形状的坯料。
实施例9：按照上述表1所示各化学元素的质量百分配比经过炼钢、热轧、冷轧，退火，获得3.0mm的基板带钢。将3.0mm的基板带钢在680℃下进行热镀，以获得铝硅锌镁镀层钢板，其中，镀液成分为8.5％Si，1％Mg，10％Zn，其余为Al及不可避免杂质。在部件预加工中，将铝硅锌镁镀层钢板激光落料成一定形状的坯料，坯料进行热处理。
需要说明的是，在本发明中，实施例1-9的高强度热冲压部件的热冲压用钢板的化学成分设计以及相关工艺均满足本发明设计规范要求。
表2-1和表2-2列出了实施例1-9的高强度热冲压部件的制造方法的相关工艺参数。
表2-1
表2-2

需要说明的是，在本发明上述表2-1中，实施例1-9在步骤(3)中的热处理工艺中的热处理温度均为范围值而非单点值，这是因为热处理炉通常分为分段控制，各段温度可以单独控制，各段温度可以不同，本发明所述的热处理温度的温度范围是各段所有温度的分布范围。
此外，需要注意的是，在实施例1-9在进行上述的制造工艺时，在步骤(3)中，实施例1-9按照设计要求进行部件热处理、转移及冲压后，可以针对实施例1-9的部件进行取样，并对各实施例部件的微观组织进行检测，以获得实施例1-9部件中的马氏体组织所占提及比例，相关检测结果列于下述表3之中。采用金相法测得部件中马氏体的百分含量：对试样进行镶嵌后，通过机械磨光、抛光、腐蚀后，利用金相图像分析软件对所采集的图像进行处理，从而获得马氏体组织的百分含量。
表3
将通过上述工艺步骤最终得到的成品实施例1-9的高强度热冲压部件分别取样，并对各实施例样品进行各项性能检测，其性能测试结果列于下述表4之中。
在本发明中，所采用的性能检测手段，如下所述：
(1)强塑积：强塑积是表征金属材料强韧性水平的综合性能指标，本发明采用部件的抗拉强度与断后伸长率的乘积求得各实施例样品的强塑积。根据金属拉伸试验方法GB/T228.1，通过拉伸试验，得到部件的抗拉强度和断后伸长率。
(2)冷弯测试：根据VDA-238标准进行冷弯测试，以获得实施例1-9样品的冷弯角。其中，冷弯角越大，则材料韧性越好；冷弯角越小，则材料韧性降低。
(3)三点弯曲试验和落锤试验：三点弯曲试验和落锤试验是将实施例热冲压部件放在弯曲装置上，调整跨距，在部件上加载进行弯曲试验，直到部件发生断裂，记录其发生断裂的最大载荷。其中，在落锤试验中，是将30kg的落锤，从50cm高度自由落体形式下降，并观察各实施例样品部件的开裂情况。
(4)扩散氢含量测试：采用线切割、冲切或带水冷的锯切方式从部件上得到试样，用丙酮超声清洗，用氢分析仪在300～400℃下测量各实施例试样中扩散氢含量。
表4列出了实施例1-9的高强度热冲压部件样品的相关性能测试结果。
表4

注：*表示采用作为防撞梁部件的实施例1-9的高强度热冲压部件进行落锤试验。
需要说明的是，由于实施例2是拼焊件，实施例3是补丁焊件，二者均涉及焊缝，受焊缝影响落锤试验不好评价；同时，最大载荷试验受焊缝影响，也不好评估。因此，实施例2和实施例3均不进行三点弯曲试验和落锤试验。
由表4可以看出，实施例1-9的高强度热冲压部件在具有较高强度的同时，还具有较优的韧性以及冷弯性能。在本发明中，实施例1-9的高强度热冲压部件的强塑积在10-12GPa·％之间，冷弯角在60-75度之间，三点弯最大载荷在13-20KN之间。
相应地，进一步参阅表4可以看出，当采用作为防撞梁部件的实施例1-9的高强度热冲压部件进行落锤试验时，实施例1-9的高强度热冲压部件均不发生开裂，其具 有较优的强塑积和韧性；同时，实施例1-9的高强度热冲压部件的扩散氢含量在0.01-0.06ppm之间，其具有较好的抗氢脆性能。
图1为实施例2的高强度热冲压部件的镀层截面微观结构照片。
如图1所示，在实施例2的高强度热冲压部件中，实施例2具有铝硅镀层，其包含基板A、镀层B。其中，在镀层A与基板B之间有明显的界面层C。
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。
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。

Claims (15)

  1. 一种生产高冷弯性能的高强度热冲压部件的方法，其特征在于，包括步骤：
    (1)制造热冲压用钢板；
    (2)部件预加工；
    (3)部件热处理、转移及冲压：将加工成指定形状的部件半成品放入热处理炉，控制热处理温度为750～960℃，控制热处理的总时间为1.5～10min，其中热处理温度在880℃以上的时间不低于1.2min；将完成热处理的半成品转移至模具中进行合模冲压，该半成品离开热处理炉的温度≥900℃；其中当制得部件的钢板厚度≤1.5mm时，控制转移时间为11～20s，当制得部件的钢板厚度＞1.5mm时，控制转移时间为13～25s；
    (4)冲压后处理：对部件进行保温均质化，然后进行机械加工以获得成品。
  2. 如权利要求1所述的用于生产高冷弯性能的高强度热冲压部件的方法，其特征在于，所述热冲压用钢板包括：无镀层钢板、铝硅镀层钢板、铝硅锌镁镀层钢板、铝硅镁镀层钢板、热镀锌镀层钢板、锌铁合金镀层钢板的至少其中之一。
  3. 如权利要求1所述的用于生产高冷弯性能的高强度热冲压部件的方法，其特征在于，所述热冲压用钢板的基板的化学成分重量百分配比为：C：0.2～0.4％，Mn：1.0～2.0％，Si：0.1～0.5％，Al：0.01～0.1％，Ti：0.01～0.1％，B：0.0005～0.01％，Cr：0.1～0.5％，以及Nb+Mo+Ni：0.3～0.6％，其中Nb，Mo，Ni中的任何一种的质量百分含量不超过0.3％；优选地，Nb的质量百分比含量为0.0001％～0.25％，Mo的质量百分比含量为0.1％～0.25％，Ni的质量百分比含量为0.05％～0.25％，如0.08％～0.2％。
  4. 如权利要求1所述的用于生产高冷弯性能的高强度热冲压部件的方法，其特征在于，在步骤(3)中，控制热处理的总时间为1.5～8min。
  5. 如权利要求1所述的用于生产高冷弯性能的高强度热冲压部件的方法，其特征在于，在步骤(3)中，控制冲压速度为40～80mm/s，并保持2～30s。
  6. 如权利要求1或5所述的用于生产高冷弯性能的高强度热冲压部件的方法，其特征在于，在步骤(3)中，冲压过程中，模具温度始终低于200℃。
  7. 如权利要求1所述的用于生产高冷弯性能的高强度热冲压部件的方法，其特征在于，在步骤(4)中，保温均质化的温度为150～250℃，时间为10～30min。
  8. 如权利要求1所述的用于生产高冷弯性能的高强度热冲压部件的方法，其特征在于，在步骤(4)中，所述机械加工包括切割、修边、冲孔、焊接的至少其中之一。
  9. 如权利要求1所述的用于生产高冷弯性能的高强度热冲压部件的方法，其特征在于，部件在步骤(3)中形成体积比例95％以上的马氏体组织。
  10. 如权利要求1所述的用于生产高冷弯性能的高强度热冲压部件的方法，其特征在于，所述热冲压部件的强塑积≥10GPa·％，冷弯角≥60度；优选地，所述热冲压部件的三点弯最大载荷≥13KN；优选地，所述热冲压部件的抗拉强度≥1500MPa；优选地，所述热冲压部件的断后伸长率≥5.5％。
  11. 采用权利要求1-10中任一项所述的方法制造得到的热冲压部件。
  12. 一种热冲压部件，其特征在于，所述热冲压部件的基板的化学成分重量百分配比为：C：0.2～0.4％，Mn：1.0～2.0％，Si：0.1～0.5％，Al：0.01～0.1％，Ti：0.01～0.1％，B：0.0005～0.01％，Cr：0.1～0.5％，以及Nb+Mo+Ni：0.3～0.6％，其中Nb，Mo，Ni中的任何一种的质量百分含量不超过0.3％；其中，所述热冲压部件的强塑积≥10GPa·％，冷弯角≥60度。
  13. 如权利要求12所述的热冲压部件，其特征在于，Nb的质量百分比含量为0.0001％～0.25％，Mo的质量百分比含量为0.1％～0.25％，Ni的质量百分比含量为0.05％～0.25％，如0.08％～0.2％。
  14. 如权利要求12或13所述的热冲压部件，其特征在于，所述基板的表面还具有涂层；优选地，所述涂层选自铝硅镀层、铝硅锌镁镀层、铝硅镁镀层、热镀锌镀层和锌铁合金镀层。
  15. 如权利要求12、13或14所述的热冲压部件，其特征在于，所述热冲压部件的三点弯最大载荷≥13KN，和/或，所述热冲压部件的扩散氢含量在0.01-0.06ppm之间，和/或，所述热冲压部件的抗拉强度≥1500MPa，和/或，所述热冲压部件的断后伸长率≥5.5％。
PCT/CN2023/084138 2022-03-28 2023-03-27 高冷弯性能高强度热冲压部件及其制造方法 WO2023185754A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210311710.0 2022-03-28
CN202210311710.0A CN116851528A (zh) 2022-03-28 2022-03-28 用于生产高冷弯性能的高强度热冲压部件的方法、热冲压部件

Publications (1)

Publication Number Publication Date
WO2023185754A1 true WO2023185754A1 (zh) 2023-10-05

Family

ID=88199153

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/084138 WO2023185754A1 (zh) 2022-03-28 2023-03-27 高冷弯性能高强度热冲压部件及其制造方法

Country Status (2)

Country Link
CN (1) CN116851528A (zh)
WO (1) WO2023185754A1 (zh)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140030544A1 (en) * 2011-04-01 2014-01-30 Jun Maki Hot stamped high strength part excellent in post painting anticorrosion property and method of production of same
US20150361532A1 (en) * 2013-05-09 2015-12-17 Hyundai Hysco Co., Ltd. Hot stamping product with enhanced toughness and method for manufacturing the same
CN106191673A (zh) * 2016-07-25 2016-12-07 江阴兴澄特种钢铁有限公司 一种冷弯性能优良屈服强度大于1100MPa的钢板及其制备方法
CN109518114A (zh) * 2018-08-08 2019-03-26 宝山钢铁股份有限公司 带铝硅合金镀层的热冲压部件的制造方法及热冲压部件
CN113106339A (zh) * 2021-03-22 2021-07-13 北京科技大学 一种超高强高塑性抗高温氧化热冲压成形钢的制备方法
CN113957337A (zh) * 2021-09-24 2022-01-21 河钢股份有限公司承德分公司 一种含钒热基镀锌板及其制备方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140030544A1 (en) * 2011-04-01 2014-01-30 Jun Maki Hot stamped high strength part excellent in post painting anticorrosion property and method of production of same
US20150361532A1 (en) * 2013-05-09 2015-12-17 Hyundai Hysco Co., Ltd. Hot stamping product with enhanced toughness and method for manufacturing the same
CN106191673A (zh) * 2016-07-25 2016-12-07 江阴兴澄特种钢铁有限公司 一种冷弯性能优良屈服强度大于1100MPa的钢板及其制备方法
CN109518114A (zh) * 2018-08-08 2019-03-26 宝山钢铁股份有限公司 带铝硅合金镀层的热冲压部件的制造方法及热冲压部件
CN113106339A (zh) * 2021-03-22 2021-07-13 北京科技大学 一种超高强高塑性抗高温氧化热冲压成形钢的制备方法
CN113957337A (zh) * 2021-09-24 2022-01-21 河钢股份有限公司承德分公司 一种含钒热基镀锌板及其制备方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Hot Working Technology", 31 January 2021, ISSN: 1001-3814, article ZHOU LIANPU; ZHU CHUNDONG; GUO YUHANG; MA RONGFEI: "Study on Heat Treatment Technology of BR1500HS Ultra-high Strength Steel for High-altitude Working Arm", pages: 128 - 131, XP009549957, DOI: 10.14158/j.cnki.1001-3814.20201900 *

Also Published As

Publication number Publication date
CN116851528A (zh) 2023-10-10

Similar Documents

Publication Publication Date Title
EP3647447B1 (en) Hot-pressed member and method for manufacturing same, and cold-rolled steel sheet for hot pressing and method for manufacturing same
EP3034641B1 (en) Ultrahigh-strength steel sheet and manufacturing method thereof
EP3812079A1 (en) Method for manufacturing equal-strength steel thin-wall welding component with aluminum or aluminum-alloy plating
JP5858032B2 (ja) 高強度鋼板およびその製造方法
EP2041330B1 (en) Process for manufacturing iron-carbon-manganese austenitic steel sheet with excellent resistance to delayed cracking, and sheet thus produced
KR102363483B1 (ko) 열간 프레스 부재 및 그 제조 방법 그리고 열간 프레스용 냉연 강판 및 그 제조 방법
KR20100019443A (ko) 양호한 스탬핑성을 갖는 저밀도 강
JP6874919B1 (ja) 高強度薄鋼板およびその製造方法
CN113106338A (zh) 一种超高强度高塑性热冲压成形钢的制备方法
EP3647448A1 (en) Hot-pressed member and method for manufacturing same, and cold-rolled steel sheet for hot pressing and method for manufacturing same
WO2021143661A1 (zh) 一种高耐蚀带钢及其制造方法
KR102569628B1 (ko) 열간 프레스 부재, 열간 프레스용 냉연 강판 및 그들의 제조 방법
KR101439613B1 (ko) 굽힘 가공성과 연신율이 우수한 고강도 고망간 강판 및 그 제조방법
JP7241889B2 (ja) 接合部品及びその製造方法
EP4332246A1 (en) Hot stamping component having tensile strength greater than or equal to 1000 mpa and fabrication method therefor
KR20140014500A (ko) 굽힘 가공성이 우수한 1500ＭＰａ급 초고강도 고망간 강판 및 그 제조방법
WO2023185754A1 (zh) 高冷弯性能高强度热冲压部件及其制造方法
KR20130138039A (ko) 충돌특성이 우수한 초고강도 강판 및 그 제조방법
KR101406634B1 (ko) 도금성 및 충돌특성이 우수한 초고강도 강판 및 그 제조방법
JP2004270006A (ja) 形状凍結性に優れた部品の製造方法
KR101406400B1 (ko) 용접성 및 가공성이 우수한 초고강도 강판 및 그 제조방법
JP5682357B2 (ja) 合金化溶融亜鉛めっき鋼板およびその製造方法
WO2023246939A1 (zh) 一种高强度高成形冷轧热镀纯锌带钢及其制造方法
KR101999017B1 (ko) 고망간 아연도금강판 및 그 제조방법
KR20220158157A (ko) 내수소취성이 우수한 열간성형용 도금강판, 열간성형 부재 및 이들의 제조방법

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23778119

Country of ref document: EP

Kind code of ref document: A1