WO2017219427A1 - Treatment process for obtaining graded performance and member thereof - Google Patents

Treatment process for obtaining graded performance and member thereof Download PDF

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Publication number
WO2017219427A1
WO2017219427A1 PCT/CN2016/090629 CN2016090629W WO2017219427A1 WO 2017219427 A1 WO2017219427 A1 WO 2017219427A1 CN 2016090629 W CN2016090629 W CN 2016090629W WO 2017219427 A1 WO2017219427 A1 WO 2017219427A1
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region
zone
hard
soft
austenite
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PCT/CN2016/090629
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French (fr)
Chinese (zh)
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易红亮
杜鹏举
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重庆哈工易成形钢铁科技有限公司
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Priority to EP16905967.2A priority Critical patent/EP3473735B1/en
Publication of WO2017219427A1 publication Critical patent/WO2017219427A1/en

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • 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
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/005—Modifying the physical properties by deformation combined with, or followed by, 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
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0294—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a localised treatment
    • 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
    • C22C38/06—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
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • 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
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing 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
    • 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
    • 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
    • C21D2211/001—Austenite
    • 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
    • C21D2211/004—Dispersions; Precipitations
    • 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
    • C21D2211/005—Ferrite
    • 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
    • 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
    • C21D2221/00—Treating localised areas of an article
    • C21D2221/10—Differential treatment of inner with respect to outer regions, e.g. core and periphery, respectively

Definitions

  • the present invention relates to a process for obtaining graded properties.
  • the present invention relates to a process for achieving a graded property on the same part, the press forming process, the heat treatment method and the mechanical properties of the hard zone being different from the press forming process and the heat treatment method of the soft zone.
  • the invention also relates to a component made via the treatment process, which has both hard and soft zones with different mechanical properties.
  • thermoforming In order to solve the problem of forming high-strength steel, a forming method called hot stamping or thermoforming for manufacturing a vehicle component having a strength of 1000 MPa or more has been commercialized.
  • the parts after thermoforming have high strength, but the elongation is very low.
  • the safety member In the actual car collision process, not only the safety member is required to have high strength to effectively resist the intrusion of the collision object, but also the requirements for ductility and toughness of the part or the whole part are required to ensure high collision energy absorption.
  • the traditional thermoforming steel 22MnB5 is difficult to combine high strength and high ductility in a single hot forming process.
  • Tailored properties to make individual parts high in strength and High Elongation
  • Two regions of different properties are combined, such as a B-pillar, with high strength and good intrusion resistance at the upper end and lower strength and better elongation at the lower end for energy absorption.
  • the splicing performance technology is usually divided into Tailord Welding Blank technology and segmentation/gradient strengthening technology through the process.
  • tailor welded blanks The general practice of tailor welded blanks is to use laser welding in some parts to weld two steel plates of different compositions and thicknesses together and obtain different properties after treatment. Dissimilar materials and welds of different thicknesses are more difficult and increase the production process and present a risk of weak welds or damage.
  • the segmentation/gradient strengthening technique achieved by the process generally controls the cooling rate of the parts during the hot stamping process, and obtains different structures to obtain different performance.
  • Mainly to control the thermal conductivity of the mold including active cooling (CN 102212742 A), passive cooling (CN104831020A, CN103521581A, CN103409613A).
  • active cooling CN 102212742 A
  • passive cooling CN104831020A
  • CN103521581A CN103409613A
  • CN102212742A By designing a hot stamping forming die of a flexible controllable large belt cooling pipe, different water flow velocities of different parts of the part are designed to achieve different cooling speeds.
  • CN104831020A Through the water channel design in the mold, the temperature is different as the distance of the cooling water left in the mold, and a non-uniform temperature field is formed in the mold to realize gradient control in the stamping process. Both CN103521581A and CN103409613A achieve performance gradients by changing the cooling rate of the part by a thermal barrier coating in the mold.
  • WO 2006/038868 A1 describes a gradient method which cools the speed by controlling the grooves between the mould and the part to be stamped to form an air gap.
  • US 2013/0048160 A1 obtains a soft phase structure by pre-cooling a region of the part to be softened between austenitizing and hot stamping of the steel sheet, and then gradually rolling the part after hot stamping.
  • CN101861265A describes a B-pillar for a vehicle and a method of manufacturing the same. The purpose is to design a B-pillar with gradient properties, with a soft zone of at least 30 mm near the lower end of the B-pillar, which is manufactured by controlling the cooling rate of the soft zone.
  • CN103878237A discloses a method for processing high-strength steel hot stamping forming parts, which performs local annealing on a uniform component after thermoforming to realize gradient of parts.
  • the method requires designing a special induction heating coil with a high annealing temperature of 600 to 1000 ° C, a preferred temperature of 800 ° C, and air cooling to 100 to 500 ° C for annealing.
  • the methods in the various comparative patents described above are characterized in that after the steel plate is austenitized and thermoformed, the microstructure of the soft zone is controlled by the phase change during the cooling process, and the cooling rate of different parts is controlled.
  • Soft zones are obtained by obtaining different strengths, or by mold cooling or by groove or pre-cooling treatment.
  • a significant disadvantage is the need to change the original mold design, poor process stability, short mold life, and it is difficult to break the 15% elongation in the soft zone based on the 22MnB5 material.
  • the invention relates to a process for realizing the gradient performance on the same part, and the stamping forming process, the heat treatment method and the mechanical property of the hard zone are different from the press forming process and the heat treatment method of the soft zone.
  • the invention also relates to a member having both a hard zone and a soft zone, wherein the hard zone can ensure small collision deformation due to high strength, and the soft zone can ensure collision suction due to high elongation. can.
  • a process for obtaining a gradient property comprising the steps of: A, preparing a billet, dividing the billet into a region to be formed into a hard region, and waiting a region forming a soft zone; B, heating the region to be formed into a hard region to above 720 ° C, transforming its microstructure into austenite while maintaining the temperature of the region to be formed into a soft region below 720 ° C; C, the billet The whole material is press-formed and cooled by any cooling after press forming; D.
  • the hard zone of the member obtained after press forming is subjected to carbon partitioning treatment to diffuse carbon from martensite to austenite.
  • a process for obtaining a gradient property comprising the steps of: A, preparing a stock material, dividing the material into regions to be formed into hard regions, and The area to be formed into the soft zone; B. The area to be formed into the hard zone is heated to above 720 ° C, and the microstructure thereof is transformed into austenite while the temperature of the region to be formed into the soft zone is lower than 720 ° C; The entire billet is press-formed and cooled by any cooling after press forming. D. The hard region of the member obtained after press forming is subjected to carbon partitioning treatment to diffuse carbon from martensite to austenite.
  • a member having a gradient property characterized in that the member is produced by the processing of the preferred embodiment described above.
  • the heating process of the hard zone and the soft zone is different (soft zone non-all austenitic heating), and the soft zone of the stamping forming process is consistent with the hard zone, so that no mold modification is required and the process reliability is good.
  • Another solution of the present invention is to first form a formed member by a press forming process, and then separately heat-treat the soft zone without any influence on the stamping die and the process. It is worth emphasizing that the soft zone elongation obtained by the two solutions of the present invention can be ensured to be greater than 15%, preferably 25 to 35%, far superior to the state of the art.
  • the performance gradient parts include, but are not limited to, B pillars, A pillars, front rails, and the like of automobiles.
  • the “hard zone” refers to the hardened zone with high strength on the part, and the “soft zone” refers to the zone where the strength is low and the elongation is high.
  • the hard zone is an area where the upper end needs to prevent collision intrusion, and the soft zone is an area where the lower end needs to absorb collision energy.
  • the microstructure of the soft zone includes, by area, from 30% to 60% of retained austenite, from 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, and less than 3% of carbide.
  • the mechanical properties of the soft zone are: tensile strength 900-1500 MPa, elongation greater than 15%.
  • the microstructure of the hard zone includes, by area: 3% to 23% of retained austenite, below 2% carbide, the rest is martensite.
  • the mechanical properties of the hard zone are: yield strength greater than 1200 MPa, tensile strength greater than 1600 MPa, and elongation greater than 10%.
  • Figure 1 is a process road view in accordance with a first embodiment of the present invention
  • Figure 2 is a process road diagram in accordance with a second embodiment of the present invention.
  • Figure 3 is a process road view in accordance with a third embodiment of the present invention.
  • Figure 4 is a process road view in accordance with a fourth embodiment of the present invention.
  • Figure 5 is a schematic illustration of a car B-pillar containing a hard zone and a soft zone.
  • a steel material for press forming comprising 0.22 to 0.48% of C, 5 to 9.5% of Mn, 0.2 to 3.0% of Si + Al, and the balance may be provided.
  • Fe and unavoidable impurities wherein the steel is one of hot rolled coil (plate), hot rolled pickled coil (plate), cold rolled annealed coil (plate), and cold rolled coated coil (plate).
  • the soft zone part is heated before heating forming to 600-780 °C (scheme 1, soft zone temperature control during hard zone austenitizing heating process) or after hot stamping (scheme 2, soft zone heating alone)
  • the temperature is 680, 700, 720, 750 ° C, etc., and is obtained by heat treatment for 0.5 to 60 minutes (in which 1, 3, 5, 10, 20, 30, 40, 50, etc. may be selected).
  • the changes of manganese, carbon and other alloying elements in austenite during annealing equilibrium of two-phase region were calculated by thermodynamic softness. Combined with the composition design and process selection, the soft zone is obtained with a volume fraction of retained austenite of 30% to 60%, a volume fraction of 40% to 70% of martensite (ferrite), and less than 3% of carbide.
  • the carbon and manganese elements diffuse into the austenite and are enriched, and the carbon content and manganese content in the alloy have reached 0.22% and 5% respectively, so the manganese in the prior art is Steel contrast, the carbon and manganese content in the austenite does not need to reach or approach the thermodynamic equilibrium to form a stable retained austenite, the final heating process
  • the residual austenite has a carbon content of 0.5% or more, a manganese content of more than 7%, austenite grains of less than 2 ⁇ m, or austenite strip thickness of less than 1 ⁇ m.
  • the retained austenite itself has high deformability and toughness, and the formation of martensite transformation and/or deformation twinning in the retained austenite is beneficial to improve the energy absorption and elongation of the steel sheet.
  • the steel material of the present invention is designed based on the composition of manganese in high carbon, having a carbon content of between 0.22 and 0.48%, preferably between 0.25 and 0.45%, and a manganese content of between 5 and 9.5%, preferably between 6 and 8%.
  • Both carbon and manganese are austenite stabilizing elements, which can strongly reduce the austenitizing temperature of steel and the phase transition temperature of martensite.
  • the austenite/ferrite slab alternates. The structure, and the carbon and manganese are distributed into the austenite, so that the austenite is stabilized below room temperature, the retained austenite itself has high deformability and toughness, and the TRIP effect can be gradually transformed into martensite during the deformation process.
  • the retained austenite has higher carbon and manganese
  • the partial austenite has higher stacking fault energy
  • the deformation twin is formed during the deformation process.
  • the work hardening rate can be further improved and the material strength and ductility can be improved at the same time.
  • the preferred annealing temperature is increased, resulting in a decrease in the content of carbon and manganese in the austenite and coarser grains, resulting in austenite stability. Poor, the toughness of the steel decreases during the deformation process.
  • the carbon content When the carbon content is high, an over-eutectoid structure may be formed.
  • a large amount of coarse carbides are easily formed to deteriorate the mechanical properties of the steel, and further improvement in the carbon content deteriorates the toughness of the hard region.
  • the steel material further comprises at least one of the following components: Cr: 0.001% to 5%; Mo: 0.001% to 2.0%; W: 0.001% to 2.0%; Ti: 0.0001% ⁇ 0.4%; Nb: 0.0001% to 0.4%; Zr: 0.0001% to 0.4%; V: 0.0001% to 0.4%; Cu: 0.0005% to 2%; Ni: 0.0005% to 3.0%; B: 0.0001% to 0.005 %.
  • the ultra-high strength and toughness matching of the stamping member can be further ensured, so that the mechanical properties thereof are: yield strength of 0.5 to 1.2 GPa, tensile strength of 1.0 to 1.5 GPa, and strong plastic product. (Tensile strength ⁇ elongation) 25 GPa% or more.
  • the steel material comprises a hot rolled steel sheet, a cold rolled steel sheet, or a steel sheet with a coated layer.
  • the steel plate with a coating layer may be a zinc-coated steel sheet which is a hot-rolled steel sheet or a cold-rolled steel sheet on which a metal zinc layer is formed.
  • the zinc-coated steel sheet comprises a material selected from the group consisting of hot dip galvanizing (GI), galvannealing (GA), zinc plating or zinc-iron plating (GE).
  • GI hot dip galvanizing
  • GA galvannealing
  • GE zinc-iron plating
  • the steel sheet with a coating layer may be a hot-rolled steel sheet or a cold-rolled steel sheet on which an aluminum-silicon layer is formed, or an organic-plated steel sheet or a steel sheet with other alloying plating layer.
  • a stock material such as a steel plate, a steel coil, or a blanked sheet or a preformed member is prepared.
  • the billet may be, for example, a billet having the composition and properties of the above steel material.
  • the entire billet is annealed, wherein the steel sheet and the coil are heat-treated in a continuous annealing line or a continuous annealing line of a steel plant.
  • the whole material can be heated to 600-720 ° C, kept for 0.5-60 minutes, and then cooled by any means (such as air-cooled, air-cooled in a continuous retreating line, or cooled or air-cooled in a hot stamping die). It is cooled to a temperature above -100 ° C, preferably to room temperature.
  • the microstructure of the billet may include: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, lower than 3% of the carbide, wherein the retained austenite comprises, by weight percentage, 7% or more of Mn and 0.5% or more of carbon.
  • the billet has a tensile strength of 900 to 1500 MPa and an elongation of 15% or more, so that the billet has good formability at room temperature.
  • the region to be formed into a hard region is heated to 720 to 850 ° C to transform its microstructure into austenite, while ensuring that the region of the soft region to be formed is at a temperature lower than 720 ° C in the process (for example, no treatment is to be formed).
  • the area of the soft zone is heated to maintain it at room temperature or it is heated to 650 ° C).
  • the hard zone may first be inductively heated to, for example, 650 ° C, the soft zone is not heated (maintained at room temperature or raised to a lower temperature due to heat conduction during heating of the hard zone), and then the blank is integrally placed
  • the furnace is heated in a furnace at a temperature of, for example, 780 °C.
  • the heating time required to heat from 650 ° C to 780 ° C is short, such as 40 seconds, and then followed by insulation for 20 seconds to achieve homogenization of the austenite structure, the billet is entirely in the furnace at 780 ° C.
  • the time is for example 1 minute.
  • the soft zone cannot be heated to 780 ° C in the furnace at 780 ° C due to the low furnace temperature.
  • it is only required to be controlled below 720 ° C.
  • the traditional hot formed steel material such as 22MnB5 due to austen
  • the texturization temperature is much higher than the material involved in the present invention and the homogenization of the austenite structure cannot be achieved within a heating time of 1 minute.
  • the entire billet is subjected to press forming.
  • the hard region After the hard region is press-formed in the full austenite region, it can be cooled to 150 to 260 ° C below its martensite transformation starting temperature point (Ms) by any cooling method (for example, in-mold cooling or air cooling).
  • the soft zone After the press forming, the soft zone can be cooled by a cooling method consistent with the hard zone, such as cooling in the mold or air cooling.
  • the microstructure of the soft zone may include: 30% to 60% austenite, 40% to 70% body-centered cubic crystal structure of martensite or ferrite, and less than 3% of carbide.
  • the hard region of the member (ie, the formed member) obtained after the press forming is subjected to carbon partitioning treatment, for example, heating the hard region to 160 to 450 ° C for 1 to 10000 seconds to cause carbon to be supersaturated from martensite.
  • Diffusion into austenite causes austenite to be rich in carbon, thereby greatly increasing the stability of austenite and increasing its residual amount at room temperature.
  • a phase transformation of martensite to austenite occurs, thereby increasing the residual austenitizing content and improving its mechanical properties.
  • the carbon partitioning process can be performed consistently with the hard zone, or the carbon partitioning process is not performed (that is, the hard zone is separately subjected to carbon partitioning treatment).
  • the mechanical properties of the soft zone of the formed member can reach a tensile strength of 900 to 1500 MPa and an elongation of 15% or more.
  • a stock material such as a steel plate, a steel coil, or a blanked sheet or a preformed member is prepared.
  • the billet may be, for example, a billet having the composition and properties of the above steel material.
  • the area of the blank to be formed into the soft zone and the hard zone is simultaneously heated and kept for 0.5 to 60 minutes, wherein the zone where the soft zone is to be formed is heated and kept at a temperature of 600 to 720 ° C, to be formed.
  • the area of the hard zone is heated to a temperature of 720-850 ° C, which transforms its microstructure into austenite.
  • the microstructure of the soft zone includes: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, less than 3%.
  • the carbides in the retained austenite include, by weight percent, 7% or more of Mn and 0.5% or more of carbon, and the hard region contains a total austenite structure, and less than 3% of the carbide.
  • the hard zone may be first inductively heated to, for example, 650 ° C, and the soft zone is heated by induction to, for example, 500 ° C, and then the billet is entirely placed in a furnace having a furnace temperature of, for example, 780 ° C for heating.
  • the heating time required to heat from 650 ° C to 780 ° C is shorter, such as 40 seconds, followed by insulation for 20 seconds to achieve uniformity of austenite structure.
  • the time for the entire billet to be in the furnace at 780 ° C is, for example, 1 minute. In this 1 minute, the soft zone cannot be heated to 780 ° C in the furnace at 780 ° C due to the low furnace temperature. In practice, it is only required to be controlled below 720 ° C.
  • the entire billet is press-formed, and after being pressed, it is cooled by any cooling method (in-mold cooling or air cooling).
  • the hard region is cooled to 150 to 260 ° C below the martensite transformation starting temperature point, and the soft zone is cooled to any temperature above -50 ° C.
  • the shaped member as a whole is cooled in a cooling manner in the hard zone, and the soft zone structural properties are also satisfactory.
  • the hard zone of the forming member is subjected to carbon partitioning treatment, for example, heating the hard zone to 160-450 ° C for 1 to 10000 seconds to cause carbon to diffuse from the supersaturated martensite to the austenite, resulting in
  • the carbon is rich in carbon, which greatly increases the stability of austenite and increases its residual amount at room temperature.
  • a phase transformation of martensite to austenite occurs, thereby increasing the residual austenitizing content and improving its mechanical properties.
  • the carbon partitioning process can be performed consistently with the hard zone, or the carbon partitioning process is not performed (that is, the hard zone is separately subjected to carbon partitioning treatment).
  • the mechanical properties of the soft zone of the formed member can reach a tensile strength of 900 to 1500 MPa and an elongation of 15% or more.
  • a stock material such as a steel plate, a steel coil, or a blanked sheet or a preformed member is prepared.
  • the billet may be, for example, a billet having the composition and properties of the above steel material.
  • the entire billet is heated to 720 to 850 ° C for 0.5 to 60 min to make it a full austenite structure and less than 3% of carbide.
  • the entire billet is press-formed, and after press forming, it is cooled by an arbitrary cooling method (in-mold cooling or air cooling).
  • an arbitrary cooling method in-mold cooling or air cooling.
  • the region where the hard region is to be formed is cooled to 150 to 260 ° C below the martensite transformation starting temperature point, and the soft zone is cooled to any temperature below -100 ° C to 600 ° C.
  • the whole of the formed member is cooled in a cooling manner in a hard zone, and the soft zone structure performance can also meet the requirements.
  • carbon-dosing treatment is performed on the region of the formed member after the press forming to be formed into a hard region, for example, heating the hard region to 160 to 450 ° C for 1 to 10000 seconds to cause carbon to be generated from the supersaturated martensite.
  • the diffusion in the austenite causes the austenite to be rich in carbon, thereby greatly increasing the stability of the austenite and increasing the residual amount at room temperature.
  • the phase transformation of martensite to austenite occurs, thereby increasing the residual austenitizing content and improving the mechanical structure thereof. performance.
  • the carbon partitioning process can be performed consistently with the hard zone, or the carbon partitioning process is not performed (that is, the hard zone is separately subjected to carbon partitioning treatment). Regardless of the carbon partitioning treatment, the mechanical properties of the soft zone of the formed member can reach a tensile strength of 900 to 1500 MPa and an elongation of 15% or more. However, in order to simplify the operation, it is preferable to carry out carbon partitioning treatment on the entire formed member.
  • the soft zone is separately heat-treated again, heated to 600 to 720 ° C, held for 0.5 to 60 minutes, and then cooled to room temperature in any manner (for example, air cooling).
  • the microstructure of the steel material includes, by area: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, below 3
  • the % of carbides in the retained austenite include 7% or more of Mn and 0.5% or more of carbon in the retained austenite, and the mechanical properties thereof have a tensile strength of 900 to 1500 MPa and an elongation of 15% or more.
  • a stock material such as a steel plate, a steel coil, or a blanked sheet or a preformed member is prepared.
  • the billet may be, for example, a billet having the composition and properties of the above steel material.
  • the entire billet is heated to 720 to 800 ° C for 0.5 to 60 min to make it a full austenite structure and less than 3% of the carbide.
  • the entire billet is press-formed, and after press forming, it is cooled by an arbitrary cooling method (in-mold cooling or air cooling).
  • an arbitrary cooling method in-mold cooling or air cooling.
  • the region to be formed into the hard region is cooled to 150 to 260 ° C below the martensite transformation starting temperature point, and the soft region is cooled to any temperature above -100 ° C or higher.
  • the whole of the formed member is cooled in a cooling manner in a hard zone, and the soft zone structure performance can also meet the requirements.
  • the soft zone is separately heat-treated again, for example, heated to 600 to 720 ° C, held for 0.5 to 60 minutes, and then cooled to room temperature in any manner (for example, air cooling).
  • the microstructure of the steel material includes, by area: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, below 3
  • the % of carbides in the retained austenite include 7% or more of Mn and 0.5% or more of carbon in the retained austenite, and the mechanical properties thereof have a tensile strength of 900 to 1500 MPa and an elongation of 15% or more.
  • carbon-dosing treatment is performed on the region of the formed member after the press forming to be formed into a hard region, for example, heating the hard region to 160 to 450 ° C for 1 to 10000 seconds to cause carbon to be generated from the supersaturated martensite. Diffusion in austenite, resulting in austenite rich in carbon, thus greatly The high austenite stability increases the residual amount at room temperature. Preferably, a phase transformation of martensite to austenite occurs, thereby increasing the residual austenitizing content and improving its mechanical properties.
  • the carbon partitioning process can be performed consistently with the hard zone, or the carbon partitioning process is not performed (that is, the hard zone is separately subjected to carbon partitioning treatment).
  • the mechanical properties of the soft zone of the formed member can reach a tensile strength of 900 to 1500 MPa and an elongation of 15% or more.
  • the soft zone may be heated by means of flame heating, induction heating, laser heating, or the like, or the whole heating furnace may be treated by a different heating temperature in the soft and hard zones.
  • a baffle plate with heat radiation is placed above and below the hard zone, a heat insulating material is wrapped on the hard zone, and a thermal insulation coating is applied on the hard zone.
  • different heating processes are performed on the hard zone and the soft zone, but the press forming process of the soft zone and the hard zone is consistent, so that no mold modification is required, and the process is not required. Good reliability.
  • Fig. 5 is a schematic view showing an automobile B-pillar comprising a hard zone and a soft zone prepared by the above-described treatment process of the present invention, wherein the hard zone is an area where the upper end needs to prevent collision intrusion, and the soft zone is a lower end which needs to absorb collision energy. Area.
  • the microstructure of the soft region of the formed member is comprised by area: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite Or ferrite, less than 3% of carbides.
  • the mechanical properties of the soft zone are: tensile strength 900-1500 MPa, elongation greater than 15%.
  • the microstructure of the hard zone includes, by area, from 3% to 23% of retained austenite, from 0 to 2% of carbide, and the balance to martensite.
  • the mechanical properties of the hard zone are: yield strength greater than 1200 MPa, tensile strength greater than 1600 MPa, and elongation greater than 10%.

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Abstract

Provided are a treatment process for obtaining graded performance and a formed member made therefrom. The process comprises the following steps: A. a blank material is prepared, and the blank material is divided into an area to be formed as a hard area and an area to be formed as a soft area; B. the area to be formed as a hard area is heated to 720ºC or higher to convert the microstructure thereof into austenite; C. the whole of the blank material is press-formed and cooled in an arbitrary cooling mode after press-forming; D. the hard area of the member obtained after press-forming is subjected to a carbon partitioning treatment to diffuse the carbon from martensite into the austenite; in step B, the temperature of the area to be formed as a soft area is kept lower than 720ºC at the same time or after step D is added step E, wherein the area to be formed as a soft area is heated to 600ºC to 720ºC for 0.5 to 60 minutes. The treatment process is simple in mould, and is good in process reliability, and the tensile strength of the soft area of 900 to 1500 MPa can be achieved, and the elongation is greater than 15%, superior to the prior art level.

Description

用于获得梯度化性能的处理工艺及其构件Process for obtaining gradient performance and its components 技术领域Technical field
本发明涉及一种用于获得梯度化性能的处理工艺。具体而言，本发明涉及一种在同一零件上实现梯度化性能的工艺，其硬区的冲压成形工艺、热处理方法及机械性能与其软区的冲压成形工艺及热处理方法有所不同。本发明还涉及经由该处理工艺制成的构件，其同时具有机械性能不同的硬区和软区。The present invention relates to a process for obtaining graded properties. In particular, the present invention relates to a process for achieving a graded property on the same part, the press forming process, the heat treatment method and the mechanical properties of the hard zone being different from the press forming process and the heat treatment method of the soft zone. The invention also relates to a component made via the treatment process, which has both hard and soft zones with different mechanical properties.
背景技术Background technique
节能减排是汽车领域迫切需要解决的问题，而汽车轻量化是实现节能减排的有效手段和途径之一。通过合理的设计和先进的成形方法可以实现汽车的轻量化。高强度钢的使用可以在实现汽车轻量化的同时保证汽车的安全性。但是高强度钢存在较低的延伸凸缘性和低的扩孔率，所以存在冲压时容易开裂以及冲压成形后零件回弹增加等问题。Energy saving and emission reduction is an urgent problem to be solved in the automotive field, and automobile lightweighting is one of the effective means and means to achieve energy saving and emission reduction. The weight of the car can be achieved through reasonable design and advanced forming methods. The use of high-strength steel can ensure the safety of the car while achieving lightweight vehicle. However, high-strength steel has a low stretch flangeability and a low hole expansion ratio, so there are problems such as easy cracking during punching and increased springback of parts after press forming.
为了解决高强度钢的成形问题，一种被称为热冲压成形或热成形、用来制造具有1000MPa或更高的强度的车辆部件的成形方法已经被商业化。但是热成形后的零件虽然强度很高，但是延伸率很低。实际的汽车碰撞过程中，不仅要求安全件有较高的强度来有效抵挡碰撞物体侵入，而且往往对零件整体或者局部有延性和韧性的要求，以保证高的碰撞吸能性。传统的热成形用钢22MnB5很难在一次热成形的工艺下同时兼具高强度和高延性，所以为了解决这个问题，工业界开发了拼接性能技术(Tailored properties)，使单个零件由高强度和高延伸率两个不同性能的区域组合在一起，例如一个B柱，在上端具有高强度和良好的防止侵入性能，而下端具有较低强度和较好的延伸率，从而达到能量吸收的目的。拼接性能技术通常又分为拼焊板(Tailor welded Blank)技术和通过工艺实现分段/梯度强化技术两种。In order to solve the problem of forming high-strength steel, a forming method called hot stamping or thermoforming for manufacturing a vehicle component having a strength of 1000 MPa or more has been commercialized. However, the parts after thermoforming have high strength, but the elongation is very low. In the actual car collision process, not only the safety member is required to have high strength to effectively resist the intrusion of the collision object, but also the requirements for ductility and toughness of the part or the whole part are required to ensure high collision energy absorption. The traditional thermoforming steel 22MnB5 is difficult to combine high strength and high ductility in a single hot forming process. Therefore, in order to solve this problem, the industry has developed Tailored properties to make individual parts high in strength and High Elongation Two regions of different properties are combined, such as a B-pillar, with high strength and good intrusion resistance at the upper end and lower strength and better elongation at the lower end for energy absorption. The splicing performance technology is usually divided into Tailord Welding Blank technology and segmentation/gradient strengthening technology through the process.
拼焊板的一般做法就是在某些部位采用激光焊接的方法，将两块不同成分和不同厚度的钢板焊接在一起，经处理后获得不同的性能。异种材料和不同厚度的焊接比较困难，并且增加了生产工序并存在潜在的焊缝弱化或破坏风险。 The general practice of tailor welded blanks is to use laser welding in some parts to weld two steel plates of different compositions and thicknesses together and obtain different properties after treatment. Dissimilar materials and welds of different thicknesses are more difficult and increase the production process and present a risk of weak welds or damage.
通过工艺实现分段/梯度强化技术一般是控制零件在热冲压过程中的冷却速度，得到不同的组织而获得不同的性能。主要有控制模具的导热，包括主动冷却(CN 102212742 A)，被动冷却(CN104831020A、CN103521581A、CN103409613A)。CN102212742A通过设计柔性可控大带冷却管道的热冲压成形模具，零件的不同区域设计不同水流速度实现不同的冷却速度。CN104831020A通过模具中的水道设计，随着冷却水在模具中留过的距离而导致温度不同，在模具中形成不均匀的温度场而实现冲压过程中的梯度控制。CN103521581A和CN103409613A均是通过在模具中的热障涂料改变零件的冷速而实现性能梯度化。The segmentation/gradient strengthening technique achieved by the process generally controls the cooling rate of the parts during the hot stamping process, and obtains different structures to obtain different performance. Mainly to control the thermal conductivity of the mold, including active cooling (CN 102212742 A), passive cooling (CN104831020A, CN103521581A, CN103409613A). CN102212742A By designing a hot stamping forming die of a flexible controllable large belt cooling pipe, different water flow velocities of different parts of the part are designed to achieve different cooling speeds. CN104831020A Through the water channel design in the mold, the temperature is different as the distance of the cooling water left in the mold, and a non-uniform temperature field is formed in the mold to realize gradient control in the stamping process. Both CN103521581A and CN103409613A achieve performance gradients by changing the cooling rate of the part by a thermal barrier coating in the mold.
WO2006/038868 A1描述了一种梯度化方法，其通过控制模具和待冲压件之间的凹槽形成空气间隙，来冷却速度。US2013/0048160A1通过在钢板奥氏体化和热冲压成形之间对需要软化的零件区域进行预冷而得到软相组织，随后经热冲压后实现零件的梯度化。WO 2006/038868 A1 describes a gradient method which cools the speed by controlling the grooves between the mould and the part to be stamped to form an air gap. US 2013/0048160 A1 obtains a soft phase structure by pre-cooling a region of the part to be softened between austenitizing and hot stamping of the steel sheet, and then gradually rolling the part after hot stamping.
CN101861265A描述了一种用于车辆的B柱及其制造方法。其目的是设计一种具有梯度性能的B柱，在靠近B柱下端固定部存在至少30mm的软区，其制造方法是控制软区的冷却速度。CN101861265A describes a B-pillar for a vehicle and a method of manufacturing the same. The purpose is to design a B-pillar with gradient properties, with a soft zone of at least 30 mm near the lower end of the B-pillar, which is manufactured by controlling the cooling rate of the soft zone.
CN103878237A公开了一种高强钢热冲压成形零件加工的方法，其对热成形后的均一构件进行局部的退火，实现零件的梯度化。该方法需要设计特殊的感应加热线圈，退火温度较高，为600～1000℃，其优选温度为800℃，并且退火后空冷至100～500℃进行加工。CN103878237A discloses a method for processing high-strength steel hot stamping forming parts, which performs local annealing on a uniform component after thermoforming to realize gradient of parts. The method requires designing a special induction heating coil with a high annealing temperature of 600 to 1000 ° C, a preferred temperature of 800 ° C, and air cooling to 100 to 500 ° C for annealing.
综上所述的各种对比专利中的方法，主要特点是在钢板奥氏体化和热成形后，通过控制软区在冷却过程中的相变获得其组织性能，通过控制不同部位的冷却速率而获得不同的强度，或通过模具冷却的设计或凹槽或预冷处理得到软区。显著的缺点是需要改变原有的模具设计，工艺稳定性差，模具寿命短，且在22MnB5的材料基础上的软区很难突破15％的延伸率。In summary, the methods in the various comparative patents described above are characterized in that after the steel plate is austenitized and thermoformed, the microstructure of the soft zone is controlled by the phase change during the cooling process, and the cooling rate of different parts is controlled. Soft zones are obtained by obtaining different strengths, or by mold cooling or by groove or pre-cooling treatment. A significant disadvantage is the need to change the original mold design, poor process stability, short mold life, and it is difficult to break the 15% elongation in the soft zone based on the 22MnB5 material.
发明内容Summary of the invention
本发明涉及一种在同一零件上实现梯度化性能的工艺，其硬区的冲压成形工艺、热处理方法及机械性能与其软区的冲压成形工艺及热处理方法有所不同。本发明还涉及同时具有硬区和软区的构件，其硬区因高强度可保证小的碰撞变形，其软区因高的延伸率可保证碰撞吸 能。The invention relates to a process for realizing the gradient performance on the same part, and the stamping forming process, the heat treatment method and the mechanical property of the hard zone are different from the press forming process and the heat treatment method of the soft zone. The invention also relates to a member having both a hard zone and a soft zone, wherein the hard zone can ensure small collision deformation due to high strength, and the soft zone can ensure collision suction due to high elongation. can.
根据本发明的一个优选实施例，提供了一种用于获得梯度化性能的处理工艺，其特征在于，包括以下步骤：A、准备坯材，将坯材划分为待形成硬区的区域和待形成软区的区域；B、将待形成硬区的区域加热到720℃以上，使其微观组织转变为奥氏体，同时保持待形成软区的区域的温度低于720℃；C、对坯材整体进行冲压成形，并在冲压成形之后以任意冷却方式进行冷却；D、对冲压成形后得到的构件的硬区进行碳配分处理，使碳从马氏体向奥氏体中扩散。According to a preferred embodiment of the present invention, there is provided a process for obtaining a gradient property, comprising the steps of: A, preparing a billet, dividing the billet into a region to be formed into a hard region, and waiting a region forming a soft zone; B, heating the region to be formed into a hard region to above 720 ° C, transforming its microstructure into austenite while maintaining the temperature of the region to be formed into a soft region below 720 ° C; C, the billet The whole material is press-formed and cooled by any cooling after press forming; D. The hard zone of the member obtained after press forming is subjected to carbon partitioning treatment to diffuse carbon from martensite to austenite.
根据本发明的另一优选实施例，提供了一种用于获得梯度化性能的处理工艺，其特征在于，包括以下步骤：A、准备坯材，将坯材划分为待形成硬区的区域和待形成软区的区域；B、将待形成硬区的区域加热到720℃以上，使其微观组织转变为奥氏体，同时保持待形成软区的区域的温度低于720℃；C、对坯材整体进行冲压成形，并在冲压成形之后以任意冷却方式进行冷却；D、对冲压成形后得到的构件的硬区进行碳配分处理，使碳从马氏体向奥氏体中扩散。According to another preferred embodiment of the present invention, there is provided a process for obtaining a gradient property, comprising the steps of: A, preparing a stock material, dividing the material into regions to be formed into hard regions, and The area to be formed into the soft zone; B. The area to be formed into the hard zone is heated to above 720 ° C, and the microstructure thereof is transformed into austenite while the temperature of the region to be formed into the soft zone is lower than 720 ° C; The entire billet is press-formed and cooled by any cooling after press forming. D. The hard region of the member obtained after press forming is subjected to carbon partitioning treatment to diffuse carbon from martensite to austenite.
根据本发明的再一优选实施例，提供了一种具有梯度化性能的构件，其特征在于，所述构件通过上述优选实施例的处理工艺制成。According to still another preferred embodiment of the present invention, there is provided a member having a gradient property, characterized in that the member is produced by the processing of the preferred embodiment described above.
在本发明的一个方案中，硬区和软区的加热工艺不同(软区非全奥氏体加热)，冲压成形工艺软区与硬区一致，因此不需要模具修改，工艺可靠性好。本发明的另一种方案则是先通过冲压成形工艺形成成形构件，然后对软区单独进行热处理，对冲压模具和工艺没有任何影响。值得强调的是，本发明的两种方案所获得的软区延伸率可确保大于15％，优选为25～35％，远优于现有技术的水平。In one aspect of the present invention, the heating process of the hard zone and the soft zone is different (soft zone non-all austenitic heating), and the soft zone of the stamping forming process is consistent with the hard zone, so that no mold modification is required and the process reliability is good. Another solution of the present invention is to first form a formed member by a press forming process, and then separately heat-treat the soft zone without any influence on the stamping die and the process. It is worth emphasizing that the soft zone elongation obtained by the two solutions of the present invention can be ensured to be greater than 15%, preferably 25 to 35%, far superior to the state of the art.
需要说明的是，在本说明书中，性能梯度化零件包括但不限于汽车的B柱、A柱、前纵梁等。“硬区”是指零件上强度高的淬硬区域，“软区”是指零件上强度低而延伸率高的区域。以汽车B柱为例，硬区是上端需要防止碰撞侵入的区域，软区是下端需要吸收碰撞能量的区域。It should be noted that in the present specification, the performance gradient parts include, but are not limited to, B pillars, A pillars, front rails, and the like of automobiles. The “hard zone” refers to the hardened zone with high strength on the part, and the “soft zone” refers to the zone where the strength is low and the elongation is high. Taking the automobile B-pillar as an example, the hard zone is an area where the upper end needs to prevent collision intrusion, and the soft zone is an area where the lower end needs to absorb collision energy.
软区的微观组织以面积计包括：30％至60％的残余奥氏体、40％至70％的体心立方晶体结构的马氏体或铁素体、低于3％的碳化物。软区的力学性能为：抗拉强度900～1500MPa，延伸率大于15％。The microstructure of the soft zone includes, by area, from 30% to 60% of retained austenite, from 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, and less than 3% of carbide. The mechanical properties of the soft zone are: tensile strength 900-1500 MPa, elongation greater than 15%.
硬区的微观组织以面积计包括：3％至23％的残余奥氏体、低于 2％的碳化物、其余为马氏体。硬区的力学性能为：屈服强度大于1200MPa，抗拉强度大于1600MPa，延伸率大于10％。The microstructure of the hard zone includes, by area: 3% to 23% of retained austenite, below 2% carbide, the rest is martensite. The mechanical properties of the hard zone are: yield strength greater than 1200 MPa, tensile strength greater than 1600 MPa, and elongation greater than 10%.
附图说明DRAWINGS
下面将参考附图来描述本发明的优选实施例，附图中：Preferred embodiments of the present invention will now be described with reference to the accompanying drawings in which:
图1是根据本发明第一实施例的工艺路线图；Figure 1 is a process road view in accordance with a first embodiment of the present invention;
图2是根据本发明第二实施例的工艺路线图；Figure 2 is a process road diagram in accordance with a second embodiment of the present invention;
图3是根据本发明第三实施例的工艺路线图；Figure 3 is a process road view in accordance with a third embodiment of the present invention;
图4是根据本发明第四实施例的工艺路线图；Figure 4 is a process road view in accordance with a fourth embodiment of the present invention;
图5是含有硬区和软区的汽车B柱的示意图。Figure 5 is a schematic illustration of a car B-pillar containing a hard zone and a soft zone.
需要指出的是，图示中实线代表必须经历的工艺路径，而虚线代表非必须的可选工艺路径。It should be noted that the solid line in the illustration represents the process path that must be experienced, while the dashed line represents the optional process path that is not required.
具体实施方式detailed description
下面将参考示例性实施例来更详细地描述本发明的工艺路线。以下实施例旨在解释本发明的示例性的工艺路线，本领域的技术人员应该清楚的是本发明不限于这些实施例。The process route of the present invention will be described in more detail below with reference to exemplary embodiments. The following examples are intended to illustrate the exemplary process routes of the present invention, and it should be apparent to those skilled in the art that the present invention is not limited to these embodiments.
根据本发明，首先可提供一种用于冲压成形的钢材，所述钢材以重量百分比计包括0.22～0.48％的C、5～9.5％的Mn、0.2～3.0％的Si+Al以及余量的Fe和不可避免的杂质，其中所述钢材为热轧卷(板)、热轧酸洗卷(板)、冷轧退火卷(板)、冷轧镀层卷(板)之一。其软区部分在冲压成形之前(方案一，硬区奥氏体化加热过程中软区温度控制)或热冲压之后(方案二，软区单独加热)经加热至600～780℃保温(其中可选择680、700、720、750℃等温度)0.5～60分钟(其中可选择1、3、5、10、20、30、40、50等时间)的热处理而获得。利用热力学软计算出两相区退火平衡时奥氏体中锰、碳及其它合金元素的变化。结合成分设计和工艺选择，软区得到残余奥氏体的体积分数在30％～60％，体积分数40％～70％的马氏体(铁素体)组织，和小于3％的碳化物。在软区的加热过程中由于碳元素和锰元素向奥氏体中扩散并富集，且合金中设计碳含量和锰含量分别已达到0.22％和5％以上，因此与现有技术的中锰钢对比，不需要达到或接近热力学平衡时奥氏体中的碳和锰含量即可形成稳定的残余奥氏体，上述加热工艺下最终实 测残余奥氏体中的碳含量在0.5％以上，锰含量大于7％，奥氏体的晶粒小于2μm或奥氏体板条厚度小于1μm。钢板在变形过程中，残余奥氏体本身具有高的变形能力和韧性，且在残余奥氏体内部产生马氏体相变和/或形变孪晶有利于提高钢板的吸能性和延伸率。According to the present invention, first, a steel material for press forming comprising 0.22 to 0.48% of C, 5 to 9.5% of Mn, 0.2 to 3.0% of Si + Al, and the balance may be provided. Fe and unavoidable impurities, wherein the steel is one of hot rolled coil (plate), hot rolled pickled coil (plate), cold rolled annealed coil (plate), and cold rolled coated coil (plate). The soft zone part is heated before heating forming to 600-780 °C (scheme 1, soft zone temperature control during hard zone austenitizing heating process) or after hot stamping (scheme 2, soft zone heating alone) The temperature is 680, 700, 720, 750 ° C, etc., and is obtained by heat treatment for 0.5 to 60 minutes (in which 1, 3, 5, 10, 20, 30, 40, 50, etc. may be selected). The changes of manganese, carbon and other alloying elements in austenite during annealing equilibrium of two-phase region were calculated by thermodynamic softness. Combined with the composition design and process selection, the soft zone is obtained with a volume fraction of retained austenite of 30% to 60%, a volume fraction of 40% to 70% of martensite (ferrite), and less than 3% of carbide. In the heating process of the soft zone, carbon and manganese elements diffuse into the austenite and are enriched, and the carbon content and manganese content in the alloy have reached 0.22% and 5% respectively, so the manganese in the prior art is Steel contrast, the carbon and manganese content in the austenite does not need to reach or approach the thermodynamic equilibrium to form a stable retained austenite, the final heating process The residual austenite has a carbon content of 0.5% or more, a manganese content of more than 7%, austenite grains of less than 2 μm, or austenite strip thickness of less than 1 μm. During the deformation of the steel sheet, the retained austenite itself has high deformability and toughness, and the formation of martensite transformation and/or deformation twinning in the retained austenite is beneficial to improve the energy absorption and elongation of the steel sheet.
本发明的钢材基于高碳中锰的成分设计，碳含量在0.22～0.48％之间，优选0.25～0.45％，锰含量在5～9.5％之间，优选为6～8％。碳和锰都是奥氏体稳定元素，均能强烈的降低钢的奥氏体化温度和马氏体开始相变温度，在退火热处理过程中，形成奥氏体/铁素体的板条交替组织，且碳和锰配分至奥氏体中，使奥氏体稳定至室温以下，残余奥氏体本身具有高的变形能力和韧性，变形过程中还可发生TRIP效应逐渐相变为马氏体，提高钢材的强度和延性。特别地，本发明的钢材中优化的成分设计及退火工艺的钢材，其残余奥氏体具有较高的碳和锰，部分奥氏体的层错能较高，变形过程中形成形变孪晶，可进一步提高加工硬化率以及同时提高材料强度和延性。当碳和锰含量较低时，为得到较多的奥氏体，伴随其优选退火温度需提高，导致奥氏体中碳和锰含量降低和晶粒较粗大，而造成奥氏体稳定性较差，在变形过程中钢的强韧性降低。碳含量较高时，可能会形成过共析的组织，在上述加热过程中容易形成较多的粗糙的碳化物而恶化钢的力学性能，且碳含量的进一步提高会恶化硬区的韧性。申请人发现把Mn含量控制在5～9.5％，碳含量控制在0.22～0.48％之间，能取得较好的强塑性。The steel material of the present invention is designed based on the composition of manganese in high carbon, having a carbon content of between 0.22 and 0.48%, preferably between 0.25 and 0.45%, and a manganese content of between 5 and 9.5%, preferably between 6 and 8%. Both carbon and manganese are austenite stabilizing elements, which can strongly reduce the austenitizing temperature of steel and the phase transition temperature of martensite. During the annealing heat treatment, the austenite/ferrite slab alternates. The structure, and the carbon and manganese are distributed into the austenite, so that the austenite is stabilized below room temperature, the retained austenite itself has high deformability and toughness, and the TRIP effect can be gradually transformed into martensite during the deformation process. Improve the strength and ductility of steel. In particular, in the optimized composition design and annealing process steel of the steel of the invention, the retained austenite has higher carbon and manganese, the partial austenite has higher stacking fault energy, and the deformation twin is formed during the deformation process. The work hardening rate can be further improved and the material strength and ductility can be improved at the same time. When the content of carbon and manganese is low, in order to obtain more austenite, the preferred annealing temperature is increased, resulting in a decrease in the content of carbon and manganese in the austenite and coarser grains, resulting in austenite stability. Poor, the toughness of the steel decreases during the deformation process. When the carbon content is high, an over-eutectoid structure may be formed. In the above heating process, a large amount of coarse carbides are easily formed to deteriorate the mechanical properties of the steel, and further improvement in the carbon content deteriorates the toughness of the hard region. The applicant found that the Mn content was controlled at 5 to 9.5%, and the carbon content was controlled between 0.22 and 0.48%, and good strong plasticity was obtained.
根据本发明的一个优选实施例，所述钢材进一步包含以下成分中的至少一种：Cr：0.001％～5％；Mo：0.001％～2.0％；W：0.001％～2.0％；Ti：0.0001％～0.4％；Nb：0.0001％～0.4％；Zr：0.0001％～0.4％；V：0.0001％～0.4％；Cu：0.0005％～2％；Ni：0.0005％～3.0％；B：0.0001％～0.005％。通过这些成分中至少一种与上述基本成分的组合，能进一步确保冲压构件的超高强韧性匹配，使得其机械力学性能达到：屈服强度0.5～1.2GPa，抗拉强度1.0～1.5GPa，强塑积(抗拉强度×延伸率)25GPa％以上。According to a preferred embodiment of the present invention, the steel material further comprises at least one of the following components: Cr: 0.001% to 5%; Mo: 0.001% to 2.0%; W: 0.001% to 2.0%; Ti: 0.0001% ～0.4%; Nb: 0.0001% to 0.4%; Zr: 0.0001% to 0.4%; V: 0.0001% to 0.4%; Cu: 0.0005% to 2%; Ni: 0.0005% to 3.0%; B: 0.0001% to 0.005 %. By combining at least one of these components with the above-mentioned basic components, the ultra-high strength and toughness matching of the stamping member can be further ensured, so that the mechanical properties thereof are: yield strength of 0.5 to 1.2 GPa, tensile strength of 1.0 to 1.5 GPa, and strong plastic product. (Tensile strength × elongation) 25 GPa% or more.
根据本发明的一个优选实施例，所述钢材包括热轧钢板、冷轧钢板、或带有涂镀层的钢板。所述带有涂镀层的钢板可为锌涂镀钢板，它是在其上形成金属锌层的热轧钢板或冷轧钢板。所述锌涂镀钢板包括选自热浸镀锌(GI)、镀锌退火(GA)、锌电镀或锌-铁电镀(GE) 中的一种。所述带有涂镀层的钢板亦可为在其上形成铝硅层的热轧钢板或冷轧钢板，或者有机镀层的钢板、或者带有其它合金化镀层的钢板。According to a preferred embodiment of the invention, the steel material comprises a hot rolled steel sheet, a cold rolled steel sheet, or a steel sheet with a coated layer. The steel plate with a coating layer may be a zinc-coated steel sheet which is a hot-rolled steel sheet or a cold-rolled steel sheet on which a metal zinc layer is formed. The zinc-coated steel sheet comprises a material selected from the group consisting of hot dip galvanizing (GI), galvannealing (GA), zinc plating or zinc-iron plating (GE). One of them. The steel sheet with a coating layer may be a hot-rolled steel sheet or a cold-rolled steel sheet on which an aluminum-silicon layer is formed, or an organic-plated steel sheet or a steel sheet with other alloying plating layer.
下面将详细描述本发明钢材的梯度化性能处理工艺的几种优选工艺路线，其能在同一零件上实现梯度化的性能。当然，本领域的技术人员应该理解的是，本发明的工艺路线并不局限于以下描述的具体工艺路线。Several preferred routes of the gradient performance treatment process for the steel of the present invention will be described in detail below to achieve the performance of the gradient on the same part. Of course, it will be understood by those skilled in the art that the process route of the present invention is not limited to the specific process routes described below.
工艺路线1：Route 1:
首先，准备坯材，比如钢板、钢卷、或落料后的板料或经预成形的构件。坯材例如可为具有上述钢材的成分和性能的坯材。First, a stock material such as a steel plate, a steel coil, or a blanked sheet or a preformed member is prepared. The billet may be, for example, a billet having the composition and properties of the above steel material.
然后，如图1所示，对坯材整体进行退火处理，其中钢板和钢卷等可在钢铁厂连续退火生产线或连续退火镀层生产线进行热处理。例如，可将坯材整体加热至600～720℃，保温0.5～60分钟，然后以任意冷却方式(比如在连退生产线的风冷、气冷，或者在热冲压的模具内冷却或空冷)，将其冷却至-100℃以上的某一温度，优选为冷却至室温。在该退火处理之后，坯材的微观组织以面积计可包括：30％至60％的残余奥氏体、40％至70％的体心立方晶体结构的马氏体或铁素体、低于3％的碳化物，其中，所述残余奥氏体中以重量百分比计包括大于等于7％的Mn以及大于等于0.5％的碳。经退火处理之后，坯材的抗拉强度为900～1500MPa，延伸率达15％以上，因此该坯材在室温下即具有良好成形性能。Then, as shown in FIG. 1, the entire billet is annealed, wherein the steel sheet and the coil are heat-treated in a continuous annealing line or a continuous annealing line of a steel plant. For example, the whole material can be heated to 600-720 ° C, kept for 0.5-60 minutes, and then cooled by any means (such as air-cooled, air-cooled in a continuous retreating line, or cooled or air-cooled in a hot stamping die). It is cooled to a temperature above -100 ° C, preferably to room temperature. After the annealing treatment, the microstructure of the billet may include: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, lower than 3% of the carbide, wherein the retained austenite comprises, by weight percentage, 7% or more of Mn and 0.5% or more of carbon. After the annealing treatment, the billet has a tensile strength of 900 to 1500 MPa and an elongation of 15% or more, so that the billet has good formability at room temperature.
然后，将待形成硬区的区域加热到720～850℃，使其微观组织转变为奥氏体，同时保证待形成软区的区域在此过程中的温度低于720℃(例如，不对待形成软区的区域进行加热而将其保持在室温，或者将其加热至650℃)。在此过程中，例如，可首先将硬区感应加热至例如650℃，软区不加热(保持在室温或由于硬区加热时的热传导而上升到一个较低的温度)，然后将坯料整体置入炉温为例如780℃的炉内进行加热。对于硬区而言，从650℃加热至780℃所需加热时间较短，比如40秒，再继而保温例如20秒以实现奥氏体组织的均匀化，则坯料整体在780℃的炉内的时间为例如1分钟。在这1分钟内，软区由于入炉温度低，在780℃的炉子中不能被加热到780℃，实际中只要控制在720℃以下即可。需要指出的是，传统的热成形钢材料(例如22MnB5)因奥氏 体化温度远高于本发明中涉及的材料而无法在1分钟的加热时间内实现奥氏体组织的均匀化。Then, the region to be formed into a hard region is heated to 720 to 850 ° C to transform its microstructure into austenite, while ensuring that the region of the soft region to be formed is at a temperature lower than 720 ° C in the process (for example, no treatment is to be formed). The area of the soft zone is heated to maintain it at room temperature or it is heated to 650 ° C). In this process, for example, the hard zone may first be inductively heated to, for example, 650 ° C, the soft zone is not heated (maintained at room temperature or raised to a lower temperature due to heat conduction during heating of the hard zone), and then the blank is integrally placed The furnace is heated in a furnace at a temperature of, for example, 780 °C. For the hard zone, the heating time required to heat from 650 ° C to 780 ° C is short, such as 40 seconds, and then followed by insulation for 20 seconds to achieve homogenization of the austenite structure, the billet is entirely in the furnace at 780 ° C. The time is for example 1 minute. In this 1 minute, the soft zone cannot be heated to 780 ° C in the furnace at 780 ° C due to the low furnace temperature. In practice, it is only required to be controlled below 720 ° C. It should be noted that the traditional hot formed steel material (such as 22MnB5) due to austen The texturization temperature is much higher than the material involved in the present invention and the homogenization of the austenite structure cannot be achieved within a heating time of 1 minute.
然后，对坯材整体进行冲压成形。硬区在全奥氏体区冲压成形后，可经由任意冷却方式(例如模具内冷却或空冷)冷却至其马氏体相变开始温度点(Ms)以下150～260℃。软区在冲压成形后，可经由与硬区一致的冷却方式进行冷却，例如模具内冷却或空冷。软区的微观组织以面积计可包括：30％至60％的奥氏体、40％至70％的体心立方晶体结构的马氏体或铁素体、以及低于3％的碳化物。Then, the entire billet is subjected to press forming. After the hard region is press-formed in the full austenite region, it can be cooled to 150 to 260 ° C below its martensite transformation starting temperature point (Ms) by any cooling method (for example, in-mold cooling or air cooling). After the press forming, the soft zone can be cooled by a cooling method consistent with the hard zone, such as cooling in the mold or air cooling. The microstructure of the soft zone may include: 30% to 60% austenite, 40% to 70% body-centered cubic crystal structure of martensite or ferrite, and less than 3% of carbide.
然后，对冲压成形后得到的构件(即成形构件)的硬区进行碳配分处理，例如将硬区加热到160～450℃、保温1～10000秒，使之发生碳从过饱和的马氏体向奥氏体中扩散，致使奥氏体中富碳，从而大大提高奥氏体的稳定性，使其在室温下的残留量增加。优选的情况是，发生马氏体向奥氏体的相变，从而增大残余奥氏体化含量，提高其机械性能。此外，对软区来而言，可与硬区进行一致的碳配分处理，或者不对其进行碳配分处理(也就是说，硬区单独进行碳配分处理)。不论是否进行碳配分处理，成形构件的软区的力学性能均可达到抗拉强度900～1500MPa，且延伸率15％以上。但是为了操作简单，优选可对成形构件整体进行碳配分处理。Then, the hard region of the member (ie, the formed member) obtained after the press forming is subjected to carbon partitioning treatment, for example, heating the hard region to 160 to 450 ° C for 1 to 10000 seconds to cause carbon to be supersaturated from martensite. Diffusion into austenite causes austenite to be rich in carbon, thereby greatly increasing the stability of austenite and increasing its residual amount at room temperature. Preferably, a phase transformation of martensite to austenite occurs, thereby increasing the residual austenitizing content and improving its mechanical properties. In addition, for the soft zone, the carbon partitioning process can be performed consistently with the hard zone, or the carbon partitioning process is not performed (that is, the hard zone is separately subjected to carbon partitioning treatment). Regardless of the carbon partitioning treatment, the mechanical properties of the soft zone of the formed member can reach a tensile strength of 900 to 1500 MPa and an elongation of 15% or more. However, in order to simplify the operation, it is preferable to carry out carbon partitioning treatment on the entire formed member.
工艺路线2：Route 2:
首先，准备坯材，比如钢板、钢卷、或落料后的板料或经预成形的构件。坯材例如可为具有上述钢材的成分和性能的坯材。First, a stock material such as a steel plate, a steel coil, or a blanked sheet or a preformed member is prepared. The billet may be, for example, a billet having the composition and properties of the above steel material.
然后，如图2所示，对坯材的待形成软区和硬区的区域同时进行加热并保温0.5～60分钟，其中，待形成软区的区域加热保温温度为600～720℃，待形成硬区的区域加热保温温度为720～850℃，使其微观组织转变为奥氏体。加热保温过程中，软区的微观组织以面积计包括：30％至60％的残余奥氏体、40％至70％的体心立方晶体结构的马氏体或铁素体、低于3％的碳化物，其残余奥氏体中以重量百分比计包括大于等于7％的Mn以及大于等于0.5％的碳，而硬区包含全奥氏体组织，以及低于3％的碳化物。在此过程中，例如，可首先将硬区感应加热至例如650℃，软区通过感应加热至例如500℃，然后将坯料整体置入炉温为例如780℃的炉内进行加热。对于硬区而言，从650℃加热至780℃所需加热时间较短，比如40秒，再继而保温例如20秒以实现奥氏体组织的均匀 化，则坯料整体在780℃的炉内的时间为例如1分钟。在这1分钟内，软区由于入炉温度低，在780℃的炉子中不能被加热到780℃，实际中只要控制在720℃以下即可。Then, as shown in FIG. 2, the area of the blank to be formed into the soft zone and the hard zone is simultaneously heated and kept for 0.5 to 60 minutes, wherein the zone where the soft zone is to be formed is heated and kept at a temperature of 600 to 720 ° C, to be formed. The area of the hard zone is heated to a temperature of 720-850 ° C, which transforms its microstructure into austenite. During the heating and holding process, the microstructure of the soft zone includes: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, less than 3%. The carbides in the retained austenite include, by weight percent, 7% or more of Mn and 0.5% or more of carbon, and the hard region contains a total austenite structure, and less than 3% of the carbide. In this process, for example, the hard zone may be first inductively heated to, for example, 650 ° C, and the soft zone is heated by induction to, for example, 500 ° C, and then the billet is entirely placed in a furnace having a furnace temperature of, for example, 780 ° C for heating. For the hard zone, the heating time required to heat from 650 ° C to 780 ° C is shorter, such as 40 seconds, followed by insulation for 20 seconds to achieve uniformity of austenite structure. The time for the entire billet to be in the furnace at 780 ° C is, for example, 1 minute. In this 1 minute, the soft zone cannot be heated to 780 ° C in the furnace at 780 ° C due to the low furnace temperature. In practice, it is only required to be controlled below 720 ° C.
然后，对坯材整体进行冲压成形，冲压后以任意冷却方式(模具内冷却或空冷)冷却。硬区被冷却至其马氏体相变开始温度点以下150～260℃，软区冷却至-50℃以上的任意温度。优选地，为了方便冲压和冷却工艺的实施，成形构件整体按照硬区的冷却方式冷却，软区组织性能也可满足要求。Then, the entire billet is press-formed, and after being pressed, it is cooled by any cooling method (in-mold cooling or air cooling). The hard region is cooled to 150 to 260 ° C below the martensite transformation starting temperature point, and the soft zone is cooled to any temperature above -50 ° C. Preferably, in order to facilitate the implementation of the stamping and cooling process, the shaped member as a whole is cooled in a cooling manner in the hard zone, and the soft zone structural properties are also satisfactory.
然后，对成形构件的硬区进行碳配分处理，例如将硬区加热到160～450℃、保温1～10000秒，使之发生碳从过饱和的马氏体向奥氏体中扩散，致使奥氏体中富碳，从而大大提高奥氏体的稳定性，使其在室温下的残留量增加。优选的情况是，发生马氏体向奥氏体的相变，从而增大残余奥氏体化含量，提高其机械性能。此外，对软区来而言，可与硬区进行一致的碳配分处理，或者不对其进行碳配分处理(也就是说，硬区单独进行碳配分处理)。不论是否进行碳配分处理，成形构件的软区的力学性能均可达到抗拉强度900～1500MPa，且延伸率15％以上。但是为了操作简单，优选可对成形构件整体进行碳配分处理。Then, the hard zone of the forming member is subjected to carbon partitioning treatment, for example, heating the hard zone to 160-450 ° C for 1 to 10000 seconds to cause carbon to diffuse from the supersaturated martensite to the austenite, resulting in The carbon is rich in carbon, which greatly increases the stability of austenite and increases its residual amount at room temperature. Preferably, a phase transformation of martensite to austenite occurs, thereby increasing the residual austenitizing content and improving its mechanical properties. In addition, for the soft zone, the carbon partitioning process can be performed consistently with the hard zone, or the carbon partitioning process is not performed (that is, the hard zone is separately subjected to carbon partitioning treatment). Regardless of the carbon partitioning treatment, the mechanical properties of the soft zone of the formed member can reach a tensile strength of 900 to 1500 MPa and an elongation of 15% or more. However, in order to simplify the operation, it is preferable to carry out carbon partitioning treatment on the entire formed member.
工艺路线3：Route 3:
首先，准备坯材，比如钢板、钢卷、或落料后的板料或经预成形的构件。坯材例如可为具有上述钢材的成分和性能的坯材。First, a stock material such as a steel plate, a steel coil, or a blanked sheet or a preformed member is prepared. The billet may be, for example, a billet having the composition and properties of the above steel material.
然后，如图3所示，将坯材整体加热至720～850℃，保温0.5～60min，使其组织为全奥氏体组织，以及低于3％的碳化物。Then, as shown in FIG. 3, the entire billet is heated to 720 to 850 ° C for 0.5 to 60 min to make it a full austenite structure and less than 3% of carbide.
然后，对坯材整体进行冲压成形，冲压成形后经任意冷却方式(模具内冷却或空冷)冷却。在冷却过程中，将待形成硬区的区域冷却至其马氏体相变开始温度点以下150～260℃，而软区冷却至-100℃以上600℃以下的任意温度。优选地，为了方便冲压和冷却的工艺实施，将成形构件整体按照硬区的冷却方式冷却，软区组织性能也可满足要求。Then, the entire billet is press-formed, and after press forming, it is cooled by an arbitrary cooling method (in-mold cooling or air cooling). During the cooling process, the region where the hard region is to be formed is cooled to 150 to 260 ° C below the martensite transformation starting temperature point, and the soft zone is cooled to any temperature below -100 ° C to 600 ° C. Preferably, in order to facilitate the process of stamping and cooling, the whole of the formed member is cooled in a cooling manner in a hard zone, and the soft zone structure performance can also meet the requirements.
然后，对冲压成形后的成形构件的待形成硬区的区域进行碳配分处理，例如将硬区加热到160～450℃、保温1～10000秒，使之发生碳从过饱和的马氏体向奥氏体中扩散，致使奥氏体中富碳，从而大大提高奥氏体的稳定性，使其在室温下的残留量增加。优选的情况是，发生马氏体向奥氏体的相变，从而增大残余奥氏体化含量，提高其机械 性能。此外，对软区来而言，可与硬区进行一致的碳配分处理，或者不对其进行碳配分处理(也就是说，硬区单独进行碳配分处理)。不论是否进行碳配分处理，成形构件的软区的力学性能均可达到抗拉强度900～1500MPa，且延伸率15％以上。但是为了操作简单，优选可对成形构件整体进行碳配分处理。Then, carbon-dosing treatment is performed on the region of the formed member after the press forming to be formed into a hard region, for example, heating the hard region to 160 to 450 ° C for 1 to 10000 seconds to cause carbon to be generated from the supersaturated martensite. The diffusion in the austenite causes the austenite to be rich in carbon, thereby greatly increasing the stability of the austenite and increasing the residual amount at room temperature. Preferably, the phase transformation of martensite to austenite occurs, thereby increasing the residual austenitizing content and improving the mechanical structure thereof. performance. In addition, for the soft zone, the carbon partitioning process can be performed consistently with the hard zone, or the carbon partitioning process is not performed (that is, the hard zone is separately subjected to carbon partitioning treatment). Regardless of the carbon partitioning treatment, the mechanical properties of the soft zone of the formed member can reach a tensile strength of 900 to 1500 MPa and an elongation of 15% or more. However, in order to simplify the operation, it is preferable to carry out carbon partitioning treatment on the entire formed member.
然后，如图3所示，对软区单独再次进行热处理，加热至600～720℃，保温0.5～60分钟，然后以任意方式(例如空冷)冷却至室温。在该热处理后，所述钢材的微观组织以面积计包括：30％至60％的残余奥氏体，40％至70％的体心立方晶体结构的马氏体或铁素体，低于3％的碳化物，其残余奥氏体中以重量百分比计包括大于等于7％的Mn以及大于等于0.5％的碳，其力学性能达到抗拉强度900～1500MPa，延伸率15％以上。Then, as shown in FIG. 3, the soft zone is separately heat-treated again, heated to 600 to 720 ° C, held for 0.5 to 60 minutes, and then cooled to room temperature in any manner (for example, air cooling). After the heat treatment, the microstructure of the steel material includes, by area: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, below 3 The % of carbides in the retained austenite include 7% or more of Mn and 0.5% or more of carbon in the retained austenite, and the mechanical properties thereof have a tensile strength of 900 to 1500 MPa and an elongation of 15% or more.
工艺路线4：Route 4:
首先，准备坯材，比如钢板、钢卷、或落料后的板料或经预成形的构件。坯材例如可为具有上述钢材的成分和性能的坯材。First, a stock material such as a steel plate, a steel coil, or a blanked sheet or a preformed member is prepared. The billet may be, for example, a billet having the composition and properties of the above steel material.
然后，如图4所示，将坯材整体加热至720～800℃，保温0.5～60min，使其组织为全奥氏体组织，以及低于3％的碳化物。Then, as shown in FIG. 4, the entire billet is heated to 720 to 800 ° C for 0.5 to 60 min to make it a full austenite structure and less than 3% of the carbide.
然后，对坯材整体进行冲压成形，冲压成形后经任意冷却方式(模具内冷却或空冷)冷却。在冷却过程中，将待形成硬区的区域冷却至其马氏体相变开始温度点以下150～260℃，而软区冷却至-100℃以上以上的任意温度。优选地，为了方便冲压和冷却的工艺实施，将成形构件整体按照硬区的冷却方式冷却，软区组织性能也可满足要求。Then, the entire billet is press-formed, and after press forming, it is cooled by an arbitrary cooling method (in-mold cooling or air cooling). During the cooling process, the region to be formed into the hard region is cooled to 150 to 260 ° C below the martensite transformation starting temperature point, and the soft region is cooled to any temperature above -100 ° C or higher. Preferably, in order to facilitate the process of stamping and cooling, the whole of the formed member is cooled in a cooling manner in a hard zone, and the soft zone structure performance can also meet the requirements.
然后，如图4所示，对软区单独再次进行热处理，例如加热至600～720℃，保温0.5～60分钟，然后以任意方式(例如空冷)冷却至室温。在该热处理后，所述钢材的微观组织以面积计包括：30％至60％的残余奥氏体，40％至70％的体心立方晶体结构的马氏体或铁素体，低于3％的碳化物，其残余奥氏体中以重量百分比计包括大于等于7％的Mn以及大于等于0.5％的碳，其力学性能达到抗拉强度900～1500MPa，延伸率15％以上。Then, as shown in FIG. 4, the soft zone is separately heat-treated again, for example, heated to 600 to 720 ° C, held for 0.5 to 60 minutes, and then cooled to room temperature in any manner (for example, air cooling). After the heat treatment, the microstructure of the steel material includes, by area: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, below 3 The % of carbides in the retained austenite include 7% or more of Mn and 0.5% or more of carbon in the retained austenite, and the mechanical properties thereof have a tensile strength of 900 to 1500 MPa and an elongation of 15% or more.
然后，对冲压成形后的成形构件的待形成硬区的区域进行碳配分处理，例如将硬区加热到160～450℃、保温1～10000秒，使之发生碳从过饱和的马氏体向奥氏体中扩散，致使奥氏体中富碳，从而大大提 高奥氏体的稳定性，使其在室温下的残留量增加。优选的情况是，发生马氏体向奥氏体的相变，从而增大残余奥氏体化含量，提高其机械性能。此外，对软区来而言，可与硬区进行一致的碳配分处理，或者不对其进行碳配分处理(也就是说，硬区单独进行碳配分处理)。不论是否进行碳配分处理，成形构件的软区的力学性能均可达到抗拉强度900～1500MPa，且延伸率15％以上。但是为了操作简单，优选可对成形构件整体进行碳配分处理。Then, carbon-dosing treatment is performed on the region of the formed member after the press forming to be formed into a hard region, for example, heating the hard region to 160 to 450 ° C for 1 to 10000 seconds to cause carbon to be generated from the supersaturated martensite. Diffusion in austenite, resulting in austenite rich in carbon, thus greatly The high austenite stability increases the residual amount at room temperature. Preferably, a phase transformation of martensite to austenite occurs, thereby increasing the residual austenitizing content and improving its mechanical properties. In addition, for the soft zone, the carbon partitioning process can be performed consistently with the hard zone, or the carbon partitioning process is not performed (that is, the hard zone is separately subjected to carbon partitioning treatment). Regardless of the carbon partitioning treatment, the mechanical properties of the soft zone of the formed member can reach a tensile strength of 900 to 1500 MPa and an elongation of 15% or more. However, in order to simplify the operation, it is preferable to carry out carbon partitioning treatment on the entire formed member.
需要指出的是，在软区的该单独的热处理过程中，例如，软区可采用比如火焰加热、感应加热、激光加热等方式加热，或者整体进入加热炉采用软硬区加热温度不同的方法处理，例如硬区上下放置防热辐射的挡板，硬区上包裹隔热材料和硬区上涂镀隔热涂层。It should be noted that in the separate heat treatment process of the soft zone, for example, the soft zone may be heated by means of flame heating, induction heating, laser heating, or the like, or the whole heating furnace may be treated by a different heating temperature in the soft and hard zones. For example, a baffle plate with heat radiation is placed above and below the hard zone, a heat insulating material is wrapped on the hard zone, and a thermal insulation coating is applied on the hard zone.
根据本发明的实施例，通过对硬区和软区进行不同的加热工艺(软区非全奥氏体加热)，但软区与硬区的冲压成形工艺保持一致，因此不需要模具修改，工艺可靠性好。According to an embodiment of the present invention, different heating processes (soft zone non-all austenitic heating) are performed on the hard zone and the soft zone, but the press forming process of the soft zone and the hard zone is consistent, so that no mold modification is required, and the process is not required. Good reliability.
本发明的上述工艺路线可以用于制造任何需要梯度化性能的零部件，其包括但不限于汽车的B柱、A柱、前纵梁等。图5示出了一种通过本发明的上述处理工艺制成的包含硬区和软区的汽车B柱的示意图，其硬区是上端需要防止碰撞侵入的区域，软区是下端需要吸收碰撞能量的区域。The above described process route of the present invention can be used to fabricate any component that requires graded performance including, but not limited to, B-pillars, A-pillars, front rails, and the like of automobiles. Fig. 5 is a schematic view showing an automobile B-pillar comprising a hard zone and a soft zone prepared by the above-described treatment process of the present invention, wherein the hard zone is an area where the upper end needs to prevent collision intrusion, and the soft zone is a lower end which needs to absorb collision energy. Area.
根据本发明的实施例，所制成的成形构件的软区的微观组织以面积计包括：30％至60％的残余奥氏体、40％至70％的体心立方晶体结构的马氏体或铁素体、低于3％的碳化物。软区的力学性能为：抗拉强度900～1500MPa，延伸率大于15％。硬区的微观组织以面积计包括：3％至23％的残余奥氏体、0～2％的碳化物、其余为马氏体。硬区的力学性能为：屈服强度大于1200MPa，抗拉强度大于1600MPa，延伸率大于10％。According to an embodiment of the present invention, the microstructure of the soft region of the formed member is comprised by area: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite Or ferrite, less than 3% of carbides. The mechanical properties of the soft zone are: tensile strength 900-1500 MPa, elongation greater than 15%. The microstructure of the hard zone includes, by area, from 3% to 23% of retained austenite, from 0 to 2% of carbide, and the balance to martensite. The mechanical properties of the hard zone are: yield strength greater than 1200 MPa, tensile strength greater than 1600 MPa, and elongation greater than 10%.
以上描述了本发明的优选实施例，但是本领域的技术人员应该明白的是，在不脱离本发明构思的前提下进行的任何可能的变化或替换，均属于本发明的保护范围。 The preferred embodiments of the present invention have been described above, but it should be understood by those skilled in the art that any possible variations or substitutions may be made without departing from the spirit and scope of the invention.

Claims (15)

  1. 一种用于获得梯度化性能的处理工艺，其特征在于，包括以下步骤：A processing process for obtaining gradient performance, comprising the steps of:
    A、准备坯材，将坯材划分为待形成硬区的区域和待形成软区的区域；A. preparing a blank material, and dividing the blank material into a region to be formed into a hard region and a region to be formed into a soft region;
    B、将待形成硬区的区域加热到720℃以上，使其微观组织转变为奥氏体，同时保持待形成软区的区域的温度低于720℃；B, the region to be formed into a hard region is heated to above 720 ° C, the microstructure is transformed into austenite, while the temperature of the region to be formed into a soft region is lower than 720 ° C;
    C、对坯材整体进行冲压成形，并在冲压成形之后以任意冷却方式进行冷却；C. Stamping the entire blank material and cooling it by any cooling method after press forming;
    D、对冲压成形后得到的构件的硬区进行碳配分处理，使碳从马氏体向奥氏体中扩散。D. Perform carbon partitioning treatment on the hard region of the member obtained after press forming to diffuse carbon from martensite to austenite.
  2. 如权利要求1所述的用于获得梯度化性能的处理工艺，其特征在于，在步骤A之后且步骤B之前还包括以下步骤：对坯材整体进行退火处理，即将坯材整体加热至600～720℃，保温0.5～60分钟，然后以任意冷却方式将其冷却至室温。The process for obtaining a gradient property according to claim 1, wherein after step A and before step B, the method further comprises the step of annealing the entire material, that is, heating the whole material to 600~. The mixture was incubated at 720 ° C for 0.5 to 60 minutes and then cooled to room temperature by any cooling method.
  3. 如权利要求2所述的用于获得梯度化性能的处理工艺，其特征在于，在步骤B中使待形成软区的区域的温度保持为720℃以下。The process for obtaining a gradient property according to claim 2, wherein the temperature of the region where the soft region is to be formed is maintained at 720 ° C or lower in the step B.
  4. 如权利要求1所述的用于获得梯度化性能的处理工艺，其特征在于，在步骤B中对坯材的待形成软区和硬区的区域同时进行加热并保温0.5～60分钟，其中，待形成软区的区域加热保温温度为600～720℃，待形成硬区的区域加热保温温度为720～850℃。The process for obtaining a gradient property according to claim 1, wherein in step B, the region of the blank to be formed into the soft zone and the hard zone is simultaneously heated and kept for 0.5 to 60 minutes, wherein The heating and holding temperature of the region to be formed into the soft zone is 600 to 720 ° C, and the heating and holding temperature of the region to be formed into the hard zone is 720 to 850 ° C.
  5. 如权利要求1-4中所述的用于获得梯度化性能的处理工艺，其特征在于，在步骤C中，将硬区冷却至其马氏体相变开始温度点以下150～260℃，软区冷却至-100℃以上的任意温度。A process for obtaining a gradient property as claimed in any of claims 1 to 4, characterized in that in step C, the hard zone is cooled to a temperature below its martensitic transformation starting point of 150 to 260 ° C, soft The zone is cooled to any temperature above -100 °C.
  6. 如权利要求1-4中任一项所述的用于获得梯度化性能的处理工艺，其特征在于，在步骤D中将硬区加热到160～450℃、保温1～10000秒。The process for obtaining a gradient property according to any one of claims 1 to 4, characterized in that in step D, the hard zone is heated to 160 to 450 ° C and held for 1 to 10,000 seconds.
  7. 如权利要求1-4中任一项所述的用于获得梯度化性能的处理工艺，其特征在于，在步骤D中，对软区也进行与硬区进行一致的碳配分处理，或者不进行碳配分处理。The process for obtaining a gradient property according to any one of claims 1 to 4, characterized in that, in the step D, the soft zone is also subjected to carbon partitioning treatment in accordance with the hard zone, or is not performed. Carbon partition treatment.
  8. 如权利要求1-4中任一项所述的用于获得梯度化性能的处理工 艺，其特征在于，冲压成形后得到的构件的软区的微观组织以面积计包括：30％至60％的残余奥氏体、40％至70％的体心立方晶体结构的马氏体或铁素体、低于3％的碳化物，软区的力学性能为：抗拉强度900～1500MPa，延伸率大于15％；硬区的微观组织以面积计包括：3％至23％的残余奥氏体、0～2％的碳化物、其余为马氏体，硬区的力学性能为：屈服强度大于1200MPa，抗拉强度大于1600MPa，延伸率大于10％。The processor for obtaining the gradient performance according to any one of claims 1 to 4. Art, characterized in that the microstructure of the soft zone of the component obtained after press forming comprises, by area: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or Ferrite, less than 3% of carbides, the mechanical properties of the soft zone are: tensile strength 900-1500MPa, elongation greater than 15%; microstructure of the hard zone includes: 3% to 23% residual The body, 0 to 2% of carbides, and the rest are martensite. The mechanical properties of the hard zone are: yield strength greater than 1200 MPa, tensile strength greater than 1600 MPa, and elongation greater than 10%.
  9. 一种用于获得梯度化性能的处理工艺，其特征在于，包括以下步骤：A processing process for obtaining gradient performance, comprising the steps of:
    A、准备坯材，将坯材划分为待形成硬区的区域和待形成软区的区域；A. preparing a blank material, and dividing the blank material into a region to be formed into a hard region and a region to be formed into a soft region;
    B、将坯材整体加热至720～800℃，保温0.5～60min，使其组织转变为奥氏体；B. The whole material is heated to 720-800 ° C, and the temperature is kept for 0.5-60 min to transform its microstructure into austenite;
    C、对坯材整体进行冲压成形，冲压成形后经任意冷却方式冷却；C. Stamping and forming the whole blank material, and cooling by any cooling method after press forming;
    D、对冲压成形后得到的构件的硬区进行碳配分处理，使碳从马氏体向奥氏体中扩散。D. Perform carbon partitioning treatment on the hard region of the member obtained after press forming to diffuse carbon from martensite to austenite.
  10. 如权利要求9所述的用于获得梯度化性能的处理工艺，其特征在于，在步骤C中，将待形成硬区的区域冷却至其马氏体相变开始温度点以下150～260℃，而软区冷却至-100℃以上的任意温度。The processing for obtaining a gradient property according to claim 9, wherein in the step C, the region to be formed into the hard region is cooled to 150 to 260 ° C below the martensite transformation starting temperature point, The soft zone is cooled to any temperature above -100 °C.
  11. 如权利要求9-10中任一项所述的用于获得梯度化性能的处理工艺，其特征在于，在步骤D之前或之后对软区单独进行热处理，即加热至600～720℃，保温0.5～60分钟，然后以任意方式冷却至室温。A process for obtaining a gradient property according to any one of claims 9 to 10, characterized in that the soft zone is separately heat-treated before or after the step D, that is, heated to 600 to 720 ° C, and kept at 0.5. ~60 minutes, then cooled to room temperature in any way.
  12. 如权利要求11所述的用于获得梯度化性能的处理工艺，其特征在于，在对软区单独进行热处理之后，坯材或冲压成形构件的微观组织以面积计包括：30％至60％的残余奥氏体，40％至70％的体心立方晶体结构的马氏体或铁素体，低于3％的碳化物，其残余奥氏体中以重量百分比计包括大于等于7％的Mn以及大于等于0.5％的碳，其力学性能达到抗拉强度900～1500MPa，延伸率15％以上。The process for obtaining a gradient property according to claim 11, wherein the microstructure of the blank or the press-formed member after the heat treatment is separately performed on the soft zone comprises: 30% to 60% by area Retained austenite, 40% to 70% body-centered cubic crystal structure of martensite or ferrite, less than 3% of carbides, and retained austenite in weight percent including 7% or more of Mn And carbon of 0.5% or more, the mechanical properties of which reach a tensile strength of 900 to 1500 MPa and an elongation of 15% or more.
  13. 一种具有梯度化性能的构件，其特征在于，所述构件通过权利要求1-12中任一项所述的处理工艺制成。A member having a grading property, characterized in that the member is produced by the treatment process according to any one of claims 1-12.
  14. 如权利要求13所述的构件，其特征在于，所述构件包括汽车的B柱、A柱、前纵梁。The member of claim 13 wherein said member comprises a B-pillar, an A-pillar, and a front longitudinal member of a vehicle.
  15. 如权利要求13-14中任一项所述的构件，其特征在于，所述构 件的软区的微观组织以面积计包括：30％至60％的残余奥氏体、40％至70％的体心立方晶体结构的马氏体或铁素体、低于3％的碳化物，软区的力学性能为：抗拉强度900～1500MPa，延伸率大于15％；硬区的微观组织以面积计包括：3％至23％的残余奥氏体、0～2％的碳化物、其余为马氏体，硬区的力学性能为：屈服强度大于1200MPa，抗拉强度大于1600MPa，延伸率大于10％。 A member according to any one of claims 13 to 14, wherein the structure The microstructure of the soft zone of the piece includes, by area: 30% to 60% of retained austenite, 40% to 70% of body-centered cubic crystal structure of martensite or ferrite, and less than 3% of carbide. The mechanical properties of the soft zone are: tensile strength 900-1500 MPa, elongation greater than 15%; microstructure of the hard zone includes: 3% to 23% retained austenite, 0-2% carbide, The rest is martensite. The mechanical properties of the hard zone are: yield strength greater than 1200 MPa, tensile strength greater than 1600 MPa, and elongation greater than 10%.
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Families Citing this family (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10619223B2 (en) 2016-04-28 2020-04-14 GM Global Technology Operations LLC Zinc-coated hot formed steel component with tailored property
WO2018055425A1 (en) * 2016-09-22 2018-03-29 Arcelormittal High strength and high formability steel sheet and manufacturing method
CN107287401B (en) * 2017-06-10 2020-10-09 山东建筑大学 Method for improving performance of traditional Q & P steel through carbon-manganese comprehensive distribution
EP3658307B9 (en) * 2017-07-25 2022-01-12 ThyssenKrupp Steel Europe AG Sheet metal component, produced by hot working a flat steel product, and method for the production thereof
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WO2019127240A1 (en) * 2017-12-28 2019-07-04 GM Global Technology Operations LLC Steel for hot stamping with enhanced oxidation resistance
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JP7214973B2 (en) * 2018-03-30 2023-01-31 マツダ株式会社 HOT PRESSING METHOD AND PROCESSING APPARATUS
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CN108754103B (en) * 2018-06-07 2019-08-30 浙江大学 A kind of superfine crystalline pure iron functionally gradient material (FGM) preparation method
WO2019241902A1 (en) * 2018-06-19 2019-12-26 GM Global Technology Operations LLC Low density press-hardening steel having enhanced mechanical properties
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US11530469B2 (en) 2019-07-02 2022-12-20 GM Global Technology Operations LLC Press hardened steel with surface layered homogenous oxide after hot forming
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CN116516252B (en) * 2023-04-28 2024-03-19 鞍钢股份有限公司 1200MPa ultra-high strength plastic hot rolled Mn-TRIP steel and preparation method thereof

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60187625A (en) * 1984-03-07 1985-09-25 Sumitomo Metal Ind Ltd Production of cold-rolled high-tensile steel plate
WO2006038868A1 (en) 2004-10-04 2006-04-13 Gestamp Hardtech Ab A method of hot stamping and hardening a metal sheet
CN101238233A (en) * 2005-08-03 2008-08-06 住友金属工业株式会社 Hot-rolled steel sheet and cold-rolled steel sheet and manufacturing method thereof
CN101861265A (en) 2007-11-15 2010-10-13 耶斯塔姆普硬技术股份公司 A B-pillar for a vehicle
CN102212742A (en) 2011-05-16 2011-10-12 马鸣图 Hot-stamping automobile part with flexibly-distributed intensity and control method thereof
CN102232123A (en) * 2008-09-18 2011-11-02 国立大学法人冈山大学 Hot-pressed steel plate member and manufacturing method therefor
EP2562272A2 (en) * 2011-08-26 2013-02-27 Rautaruukki OYJ Method for producing steel product having excellent mechanical properties, steel product produced with the method and its use
US20130048160A1 (en) 2010-03-16 2013-02-28 Jan Larsson Press hardening plant and a method of press hardening a steel sheet blank
CN103409613A (en) 2013-08-30 2013-11-27 上海交通大学 Method for realizing gradient property distribution of hot stamping workpiece
CN103521581A (en) 2013-10-23 2014-01-22 武汉理工大学 Method and die for obtaining mechanical performance gradient hot stamping part
CN103878237A (en) 2014-03-24 2014-06-25 华中科技大学 Method for machining high-strength steel hot stamping formed parts
CN104726677A (en) * 2015-03-30 2015-06-24 盐城科奥机械有限公司 Fixed lining plate type compartment type heating furnace and segmented thermoforming strengthening process thereof
CN104729278A (en) * 2015-03-30 2015-06-24 盐城科奥机械有限公司 Mobile roller-type van-type heating furnace and hot-forming subsection strengthening technique
CN104831020A (en) 2015-04-03 2015-08-12 燕山大学 Method for stamping quenching molding in non-uniform temperature field

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5983744A (en) * 1982-11-04 1984-05-15 Sumitomo Metal Ind Ltd Shape memory alloy
JPH04333526A (en) * 1991-05-08 1992-11-20 Sumitomo Metal Ind Ltd Hot rolled high tensile strength steel plate having high ductility and its production
FR2851774B1 (en) * 2003-02-27 2006-08-18 Inst Francais Du Petrole LOW-ALLOY ANTICOKAGE STEELS WITH INCREASED SILICON AND MANGANESE CONTENT, AND THEIR USE IN REFINING AND PETROCHEMICAL APPLICATIONS
JP5287770B2 (en) * 2010-03-09 2013-09-11 Ｊｆｅスチール株式会社 High strength steel plate and manufacturing method thereof
JP5982906B2 (en) * 2012-03-19 2016-08-31 Ｊｆｅスチール株式会社 Method for producing high-strength hot-dip galvanized steel sheet
JP5982905B2 (en) * 2012-03-19 2016-08-31 Ｊｆｅスチール株式会社 Method for producing high-strength hot-dip galvanized steel sheet
JP5962541B2 (en) * 2012-07-23 2016-08-03 Ｊｆｅスチール株式会社 Manufacturing method of high-strength steel sheet
JP5962540B2 (en) * 2012-07-23 2016-08-03 Ｊｆｅスチール株式会社 Manufacturing method of high-strength steel sheet
EP2940176B1 (en) * 2013-03-04 2019-03-27 JFE Steel Corporation High-strength steel sheet, method for manufacturing same, high-strength molten-zinc-plated steel sheet, and method for manufacturing same

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60187625A (en) * 1984-03-07 1985-09-25 Sumitomo Metal Ind Ltd Production of cold-rolled high-tensile steel plate
WO2006038868A1 (en) 2004-10-04 2006-04-13 Gestamp Hardtech Ab A method of hot stamping and hardening a metal sheet
CN101238233A (en) * 2005-08-03 2008-08-06 住友金属工业株式会社 Hot-rolled steel sheet and cold-rolled steel sheet and manufacturing method thereof
CN101861265A (en) 2007-11-15 2010-10-13 耶斯塔姆普硬技术股份公司 A B-pillar for a vehicle
CN102232123A (en) * 2008-09-18 2011-11-02 国立大学法人冈山大学 Hot-pressed steel plate member and manufacturing method therefor
US20130048160A1 (en) 2010-03-16 2013-02-28 Jan Larsson Press hardening plant and a method of press hardening a steel sheet blank
CN102212742A (en) 2011-05-16 2011-10-12 马鸣图 Hot-stamping automobile part with flexibly-distributed intensity and control method thereof
EP2562272A2 (en) * 2011-08-26 2013-02-27 Rautaruukki OYJ Method for producing steel product having excellent mechanical properties, steel product produced with the method and its use
CN103409613A (en) 2013-08-30 2013-11-27 上海交通大学 Method for realizing gradient property distribution of hot stamping workpiece
CN103521581A (en) 2013-10-23 2014-01-22 武汉理工大学 Method and die for obtaining mechanical performance gradient hot stamping part
CN103878237A (en) 2014-03-24 2014-06-25 华中科技大学 Method for machining high-strength steel hot stamping formed parts
CN104726677A (en) * 2015-03-30 2015-06-24 盐城科奥机械有限公司 Fixed lining plate type compartment type heating furnace and segmented thermoforming strengthening process thereof
CN104729278A (en) * 2015-03-30 2015-06-24 盐城科奥机械有限公司 Mobile roller-type van-type heating furnace and hot-forming subsection strengthening technique
CN104831020A (en) 2015-04-03 2015-08-12 燕山大学 Method for stamping quenching molding in non-uniform temperature field

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3473735A4 *

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