EP2823905B2 - Heisspressformverfahren und karosseriekomponenten eines kraftfahrzeugs - Google Patents

Heisspressformverfahren und karosseriekomponenten eines kraftfahrzeugs Download PDF

Info

Publication number
EP2823905B2
EP2823905B2 EP13757922.3A EP13757922A EP2823905B2 EP 2823905 B2 EP2823905 B2 EP 2823905B2 EP 13757922 A EP13757922 A EP 13757922A EP 2823905 B2 EP2823905 B2 EP 2823905B2
Authority
EP
European Patent Office
Prior art keywords
less
steel sheet
press
forming
warm
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP13757922.3A
Other languages
English (en)
French (fr)
Other versions
EP2823905A4 (de
EP2823905A1 (de
EP2823905B1 (de
Inventor
Yuichi Tokita
Yoshikiyo Tamai
Toru Minote
Takeshi Fujita
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
JFE Steel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=49116317&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP2823905(B2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by JFE Steel Corp filed Critical JFE Steel Corp
Publication of EP2823905A1 publication Critical patent/EP2823905A1/de
Publication of EP2823905A4 publication Critical patent/EP2823905A4/de
Application granted granted Critical
Publication of EP2823905B1 publication Critical patent/EP2823905B1/de
Publication of EP2823905B2 publication Critical patent/EP2823905B2/de
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21K—MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS
    • B21K7/00—Making railway appurtenances; Making vehicle parts
    • B21K7/12—Making railway appurtenances; Making vehicle parts parts for locomotives or vehicles, e.g. frames, underframes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/02—Stamping using rigid devices or tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/20—Deep-drawing
    • B21D22/208—Deep-drawing by heating the blank or deep-drawing associated with heat treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J1/00—Preparing metal stock or similar ancillary operations prior, during or post forging, e.g. heating or cooling
    • B21J1/06—Heating or cooling methods or arrangements specially adapted for performing forging or pressing operations
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/62—Quenching devices
    • C21D1/673—Quenching devices for die quenching
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • 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
    • C22C38/007—Ferrous alloys, e.g. steel alloys containing silver
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/08—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
    • C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
    • C22C38/105—Ferrous alloys, e.g. steel alloys containing cobalt containing Co and Ni
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06—Zinc or cadmium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/26—After-treatment
    • C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/26—After-treatment
    • C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
    • C23C2/29—Cooling or quenching
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00—Making other particular articles
    • B21D53/88—Making other particular articles other parts for vehicles, e.g. cowlings, mudguards
    • 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

Definitions

  • the present invention relates to a warm press forming method that can suppress defects in dimensional accuracy due to geometric changes such as springback that occur in a high strength steel sheet being press-formed.
  • the present invention also relates to an automobile frame component produced by the warm press forming method.
  • high strength steel sheets have been increasingly applied to automotive parts. It is generally known, however, that high strength steel sheets exhibit poor press formability, undergo considerable geometric changes (springback) caused by elastic recovery after being removed from the die, and are prone to defects in dimensional accuracy. Thus, there are currently a limited number of parts that can be obtained by applying press forming to high strength steel sheets.
  • JP 2005-205416 A discloses an example of hot press forming being applied to a high strength steel sheet in which a steel sheet is press-formed after being heated to a predetermined temperature.
  • JP 2006-212663 A discloses warm press forming methods for forming steel sheets having tensile strengths of 440 MPa or more. This requires that the temperature prior to press forming of the steel sheet is high, from 750°C to 1300°C.
  • US 2005/257862 A1 discloses warm press forming methods for forming steel sheets for automotive bodies having a tensile strength of 440 MPa or more. This also requires high temperatures of at least 725°C.
  • the aforementioned hot press forming involves forming of a steel sheet at temperatures higher than those at which cold press forming is performed, so as to reduce the deformation resistance of the steel sheet for press forming, in other words, to increase the deformation capacity thereof, aiming to improve the shape fixability and at the same time prevent the occurrence of press cracking.
  • press forming is based on draw forming.
  • edges of the heated steel sheet (which will be also called “blank”) are compressed between a die and a blank holder during the formation process, and accordingly the edges of the blank and other portions thereof contact with, e.g., the die for different times.
  • a drop in the temperature of the contact zone of the blank during the press forming process leads to a non-uniform temperature distribution in the press-formed part immediately after the formation (hereinafter also called "panel”) due to the difference in the contact time with the aforementioned die, and so on.
  • panel non-uniform temperature distribution in the press-formed part immediately after the formation
  • general hot press forming involves heating of a steel sheet to the austenite region as well as cooling of the steel sheet accompanying quenching and phase transformation, and consequently, the microstructure of the steel sheet tends to change after the formation, causing the problem of large variations in the tensile properties, such as strength and ductility, of the press-formed part.
  • the present invention has been developed to solve the aforementioned problem, and an object of the present invention is to provide a warm press forming method that can suppress geometric changes such as springback that occur in a panel, thereby improving the dimensional accuracy of the panel and obtaining the desired mechanical properties in the press-formed part. Another object of the present invention is to provide an automobile frame component produced by the warm press forming method.
  • the present inventors tried to limit the heating temperature of the high strength steel sheet, which would otherwise need to be heated to the austenite region with conventional hot press forming, below the austenite transformation temperature.
  • the present inventors have made intensive studies on forming methods and forming conditions to determine the conditions under which geometric changes caused by springback can be suppressed.
  • the warm press forming according to the present invention does not involve quenching and/or phase transformation before and after the forming process and can directly make use of the mechanical properties of steel sheets as blank material, thereby allowing for stable production of press-formed parts with desired properties.
  • Heating Temperature of Steel Sheet 400 °C to 700 °C
  • the heating temperature of the steel sheet is defined to be in the range of 400 °C to 700 °C.
  • the heating temperature of the steel sheet is 400 °C or higher and lower than 650 °C, it is possible to suppress oxidation of surfaces of the steel sheet and/or formation of cracks, and furthermore, to prevent an excessive increase in press load, which is still more advantageous.
  • press forming is usually performed using draw forming.
  • draw forming even a warm (or hot) press forming process is generally carried out by means of a blank holder arranged as shown in FIG. 1 so as to suppress wrinkles that would occur during the forming process, while applying tension to sidewall portions with edges of the blank being compressed between the blank holder and the upper die.
  • a die is labeled 1
  • a punch is labeled 2
  • a blank holder is labeled 3
  • a heated steel sheet (blank) is labeled 4
  • a press-formed part (panel) after the formation is labeled 5
  • flange portions are labeled 6
  • sidewall portions are labeled 7.
  • an automobile frame component is often worked to form a closed cross section by joining members having a substantially hat-shaped cross section by spot welding and the like.
  • the edges of the blank compressed as shown in FIG. 2(b) provide flange portions of the panel after the formation.
  • the flange portions are required to be flat since they are points at which panels are joined together by spot welding and the like. This is the reason why the formation is performed while applying blank holding force to edges of the blank as mentioned above.
  • the edges of the blank are continuously compressed between the blank holder and the upper die from the early stage of the forming process until the completion of the process. Consequently, the heated steel sheet (blank) is subject to a heat transfer from edges of the blank to the die during the press forming process, with the result that the edges of the blank are susceptible to a temperature drop, leading to a large difference in temperature among flange portions and other portions of the panel immediately after the formation.
  • the present inventors firstly focused on and investigated the relationship, in the case of a press forming process using draw forming, between the difference in average temperature among flange portions and other portions of a panel and the amount of geometric changes made to the panel from the time immediately after press forming until the end of air cooling.
  • difference in average temperature means a difference in average temperature immediately after press forming, unless otherwise specified.
  • immediately after press forming refers to a point in time that represents the end of a holding process at a press bottom dead point and the start of air cooling of a panel after being removed from the die.
  • the term "the amount of geometric changes” means a difference (variation) between the geometry of a panel after removal from the die immediately after warm press forming and the geometry of the panel after air cooling.
  • FIG. 3(a) is a graph showing the relationship between the difference in average temperature among flange portions and other portions of a panel obtained by warm press forming using draw forming and the amount of geometric changes made to the panel from the time immediately after press forming (the time when the panel was removed from the die) until the end of air cooling.
  • a steel sheet of 980 MPa grade was used and the heating temperature thereof was set to be 600 °C.
  • the aforementioned amount of geometric changes was determined by an opening amount a, which was measured at the edges of the flanges in relation to a reference panel (a panel removed from the die immediately after press forming), as shown in FIG. 3(b) .
  • a reference panel is labeled 8 (dashed line)
  • an air-cooled panel is labeled 9 (thick solid line)
  • a panel at the press bottom dead point is labeled 10 (thin solid line).
  • the larger the aforementioned difference in average temperature in a panel the larger the amount of geometric changes made to the panel from the time it is removed from the die immediately after press forming until the end of air cooling.
  • the amount of geometric changes becomes greater than 1.0 mm where the difference in average temperature exceeds 150 °C, it is important that the difference in average temperature be kept within 150 °C, preferably within 100 °C, for reducing the amount of geometric changes caused by the temperature difference in the panel.
  • the present inventors found that the difference in average temperature among flange portions and other portions of a panel is closely correlated with the amount of geometric changes made to the panel from the time it is removed from the die immediately after press forming until the end of air cooling. Based on this finding, the present inventors have made studies on how to suppress the aforementioned difference in average temperature during draw forming. As a result, we have conceived of holding a steel sheet at the press bottom dead point as shown in FIG. 1(c) over a certain period of time.
  • FIG. 4(a) shows the relationship between the difference in average temperature among flange portions and other portions of those panels having a substantially hat-shaped cross section that were obtained warm press forming using draw forming and the holding time at the press bottom dead point; and FIG. 4(b) shows the relationship between the amount of geometric changes made to the panels from the time they were removed from the die immediately after press forming until the end of air cooling and the holding time at the press bottom dead point.
  • steel sheets of 980 MPa grade were used and the heating temperatures thereof were set to be 600 °C, 650 °C, and 700 °C, respectively.
  • the difference in average temperature among flange portions and other portions of the panel may be kept within 150 °C and the amount of geometric changes made to the panel may be suppressed to 1.0 mm or less, by setting the holding time at press bottom dead point to three seconds or more. It can also be understood that even for the heating temperatures of 650 °C and 700 °C, the difference in average temperature among flange portions and other portions of each panel may be kept within 150 °C and the amount of geometric changes made to each panel may be suppressed to 1.0 mm or less, by setting the holding time at press bottom dead point to three seconds or more.
  • a holding time at press bottom dead point exceeding five seconds is disadvantageous in terms of production efficiency, although the amount of geometric changes is kept substantially constant for any of the heating temperatures.
  • a steel sheet is held at the press bottom dead point for three to five seconds, at the time of press forming using draw forming.
  • the heating temperature of the steel sheet is set to 400 °C to 700 °C and the holding time at press bottom dead point to three seconds or more.
  • the pressing speed is preferably in the range of about 10 spm to 15 spm (strokes per minute, which represents the number of parts that can be formed in one minute plus any additional time, if applicable, taken to hold parts at the press bottom dead point).
  • flange portions are continuously compressed during the formation, which provides the benefit of making the flange portions less prone to wrinkle formation.
  • the present invention involves holding a steel sheet at the press bottom dead point as described above, which makes it possible to suppress wrinkle formation in flange portions in a more effective manner.
  • the heating of the steel sheet has the same effect irrespective of the heating method used, such as heating in an electric furnace, electrical heating, and rapid heating using far infrared heating.
  • the warm press forming method according to the present invention is applied to a steel sheet having a tensile strength of 440 MPa or more. Further, the warm press forming method according to the present invention may preferably be applied to a steel sheet having a tensile strength of 780 MPa or more, and even 980 MPa or more.
  • the warm press forming method according to the present invention makes it possible to directly make use of the mechanical properties of steel sheets as blanks, thereby allowing a press-formed part obtained by press forming of a steel sheet to have a tensile strength which is not greatly different from, or 80 % to 110 % of, that of the steel sheet before press forming. Furthermore, it is possible to obtain a press-formed part that retains, even after the press forming process, a tensile strength which is almost as high as that of the steel sheet before press forming (or, that has a tensile strength of 95 % to 100 % of the tensile strength of the steel sheet prior to the press forming process), depending on the forming conditions and the properties of the steel sheet. Therefore, depending on the properties required for press-formed parts, the use of steel sheets having the corresponding properties as blanks allows for stable production of press-formed parts with desired properties.
  • Carbon (C) is an important element in that it forms carbides with other elements, such as Ti, V, Mo, W, Nb, Zr, and Hf, which exhibit fine particle distribution in the matrix to thereby increase the strength of a steel sheet.
  • the content of C in steel is preferably 0.015 % or more.
  • the content of C exceeds 0.16 %, the ductility and toughness are significantly reduced, which makes it impossible to ensure good impact absorption ability (such as expressed by "tensile strength TS ⁇ total elongation El"). Therefore, the content of C is preferably in the range of 0.015 % to 0.16 %, more preferably in the range of 0.03 % to 0.16 %, and still more preferably in the range of 0.04 % to 0.14 %.
  • Silicon (Si) is a solid-solution-strengthening element that suppresses the reduction of strength in a high temperature range, and consequently adversely affects the formability in a warm-forming temperature range (warm formability). Therefore, the content of Si in steel is preferably kept as low as possible in the present invention, but a Si content of up to 0.2 % is tolerable. In view of this, the content of Si is preferably 0.2 % or less, more preferably 0.1 % or less, and still more preferably 0.06 % or less. Note that the content of Si may be reduced to impurity level.
  • Manganese (Mn) is also a solid-solution-strengthening element, like Si, that suppresses the reduction of strength in a high temperature range, and consequently adversely affects the formability in a warm-forming temperature range (warm formability). Therefore, the content of Mn in steel is preferably kept as low as possible in the present invention, but a Mn content of up to 1.8 % is tolerable. In view of this, the content of Mn is preferably 1.8 % or less, more preferably 1.3 % or less, and still more preferably 1.1 % or less. Note that if the content of Mn is too low, the austenite ( ⁇ ) to ferrite ( ⁇ ) transformation temperature may rise excessively, which could lead to coarsening of carbides. Therefore, the content of Mn is preferably 0.5 % or more.
  • Phosphorus (P) is an element that has a very high, solid-solution-strengthening ability, suppresses the reduction of strength in a high temperature range, and consequently adversely affects the formability in a warm-forming temperature range (warm formability). Additionally, P exists in a segregated manner at grain boundaries, thereby lowering the ductility during and after warm forming.
  • the content of P in steel is preferably kept as low as possible, but a P content of up to 0.035 % is tolerable. Accordingly, the content of P is preferably 0.035 % or less, more preferably 0.03 % or less, and still more preferably 0.02 % or less.
  • S Sulfur
  • S is an element that exists as inclusion in steel. S reduces the strength of the steel sheet when bonded to Ti, while forming sulfides when bonded to Mn, leading to a reduction of the ductility of the steel sheet at room temperature, under warm condition, and the like. Therefore, the content of S is preferably kept as low as possible, but a S content of up to 0.01 % is tolerable. Accordingly, the content of S is preferably 0.01 % or less, more preferably 0.005 % or less, and still more preferably 0.004 % or less.
  • Aluminum (Al) is an element that acts as a deoxidizer. To obtain this effect, it is desirable that Al is contained in steel by 0.02 % or more. However, if the content of Al exceeds 0.1 %, more oxide-based inclusions form, significantly reducing the ductility under warm condition. Therefore, the content of Al is preferably 0.1 % or less, and more preferably 0.07 % or less.
  • N Nitrogen
  • the content of N is preferably kept as low as possible, but a N content of up to 0.01 % is tolerable. Therefore, the content of N is preferably 0.01 % or less, and more preferably 0.007 % or less.
  • Titanium (Ti) is an element that forms carbides when bonded to C and thereby contributes to increased strength of the steel sheet.
  • the content of Ti is preferably 0.13 % or more.
  • the content of Ti is preferably 0.25 % or less, more preferably 0.14 % to 0.22 %, and still more preferably 0.15 % to 0.22 %.
  • Expression (1) is a requirement to enable the strengthening by precipitation with carbides, which will be described later, and to ensure a high strength as desired after warm forming.
  • the contents of C and Ti satisfy Expression (1), it is possible to allow precipitation of a desired amount of carbides, thereby ensuring a high strength as desired.
  • the result of ([%C] / 12) / ([%Ti] / 48) is less than 1.05, not only does the grain boundary strength decrease, but also the carbides exhibit lower thermal stability upon heating. Accordingly, the carbides are more prone to coarsening, which makes it impossible to achieve a high strength as desired.
  • the steel sheet that can preferably be used in the warm press forming method according to the present invention may optionally contain the following elements as appropriate.
  • Vanadium (V), molybdenum (Mo), tungsten (W), niobium (Nb), zirconium (Zr), and hafnium (Hf) are elements, like Ti, that form carbides to contribute to increasing the strength of the steel sheet. Therefore, the steel sheet may contain at least one element in addition to Ti, selected from V, Mo, W, Nb, Zr, and Hf, if a further enhancement of its strength is required.
  • the content of V is 0.01 % or more
  • the content of Mo is 0.01 % or more
  • the content of W is 0.01 % or more
  • the content of Nb is 0.01 % or more
  • the content of Zr is 0.01 % or more
  • the content of Hf is 0.01 % or more.
  • the content of V exceeds 1.0 %, carbides are more prone to coarsening; in particular, coarsening of carbides in a warm-forming temperature range makes it difficult to control the average particle size of the carbides after being cooled to room temperature to be 10 nm or less.
  • the content of V is preferably 1.0 % or less, more preferably 0.5 % or less, and still more preferably 0.2 % or less.
  • the contents of Mo and W are more than 0.5 % and 1.0 %, respectively, the ⁇ -to- ⁇ transformation is exceedingly delayed. As a result, bainite phase and martensite phase exist in a mixed manner in the microstructure of the steel sheet, which makes it difficult to obtain ferrite single phase, which will be described later.
  • the contents of Mo and W are preferably 0.5 % or less and 1.0 % or less, respectively.
  • Nb, Zr, and Hf are contained in steel by more than 0.1 %, respectively, coarse carbides are not completely dissolved and remain in slab being reheated. Consequently, micro voids form more easily during warm forming.
  • the contents of Nb, Zr, and Hf are preferably 0.1 % or less, respectively.
  • the steel sheet that can preferably be used in the warm press forming method according to the present invention may optionally contain the following elements as appropriate.
  • Boron (B) is an element that acts to inhibit nucleation of the ⁇ -to- ⁇ transformation to lower the ⁇ -to- ⁇ , transformation point, thereby contributing to the refinement of carbides. To obtain this effect, it is desirable that the content of B is 0.0002 % or more. However, containing over 0.003 % of B does not increase this effect, but is rather economically disadvantageous. Therefore, the content of B is preferably 0.003 % or less, and more preferably 0.002 % or less.
  • Magnesium (Mg), calcium (Ca), yttrium (Y), and REM all act as refining inclusions, which action provides an effect of suppressing stress concentration in the vicinity of inclusions and the base material during warm forming, and thereby improving the ductility. Therefore, these elements may optionally be contained in steel.
  • the REM which is an abbreviation for Rare Earth Metal, represents lanthanoid elements.
  • Mg, Ca, Y, and REM are contained in steel in an excessive amount over 0.2 %, respectively, these elements compromise castability (which is the ability of a molten steel to flow through a mold before solidification; higher castability represents better flowability of a molten steel), rather leading to lower ductility. It is thus preferred that the content of Mg is 0.2 % or less, the content of Ca is 0.2 % or less, the content of Y is 0.2 % or less, and the content of REM is 0.2 % or less.
  • the content of Mg is in the range of 0.001 % to 0.1 %
  • the content of Ca is in the range of 0.001 % to 0.1 %
  • the content of Y is in the range of 0.001 % to 0.1 %
  • the content of REM is in the range of 0.001 % to 0.1 %.
  • the total amount of these elements is adjusted to be 0.2 % or less, and more preferably 0.1 % or less.
  • Antimony (Sb), copper (Cu), and tin (Sn) are elements that concentrate near surfaces of a steel sheet and has an effect of suppressing softening of the steel sheet that would be caused by nitriding of the surfaces of the steel sheet during warm forming. Therefore, at least one of these elements may optionally be contained in steel.
  • Cu is also effective for improving anti-corrosion property. To obtain this effect, it is desirable that Sb, Cu, and Sn are contained in steel by 0.005 % or more, respectively. However, if Sb, Cu, and Sn are contained in steel in excessive amounts over 0.1 %, 0.5 %, and 0.1%, respectively, the resulting steel sheet has a poor surface texture. Therefore, it is preferred that the content of Sb is 0.1 % or less, the content of Cu is 0.5 % or less, and the content of Sn is 0.1 % or less.
  • Ni and Cr are elements that contribute to increased strength of steel. At least one of these elements may optionally be contained in steel.
  • Ni is an austenite-stabilizing element that suppresses formation of ferrite at high temperature and contributes to increased strength of the steel sheet.
  • Cr is a quench-hardenability-improving element that suppresses, as is the case with Ni, formation of ferrite at high temperature and contributes to increased strength of the steel sheet.
  • Ni and Cr are contained in steel by 0.01 % or more. However, if Ni and Cr are contained in steel in an excessive amount over 0.5 %, respectively, formation of a low temperature transformation phase, such as martensite phase and bainite phase, is induced. A low temperature transformation phase, such as martensite phase and bainite phase, shows recovery during heating, thereby causing a reduction in the strength after warm forming. To obtain this effect, it is preferred that Ni and Cr are contained in steel by 0.5 % or less, and more preferably by 0.3 % or less, respectively.
  • a total amount of 2.0 % or less of the above elements is tolerable since it does not affect the strength or warm formability of the steel sheet.
  • the total amount is more preferably 1.0 % or less.
  • the balance other than the aforementioned components includes Fe and incidental impurities.
  • the steel sheet has a metal structure of ferrite single phase.
  • ferrite single phase is not only intended to represent a situation where the area ratio of ferrite phase is 100 %, but also to encompass a substantially ferrite single phase where the area ratio of ferrite phase is 95 % or more.
  • the steel sheet having a ferrite single phase as its metal structure it is possible to retain excellent ductility and even suppress changes to the material properties caused by heating.
  • the coexistence of hard phases, such as bainite phase and martensite phase, in the microstructure causes recovery of dislocations introduced to the hard phases by heating, and consequently the hard phases soften, which makes it impossible to maintain the strength of the steel sheet even after warm forming. Accordingly, the absence of pearlite, bainite phase, and martensite phase delivers better results, although the coexistence of such hard phases and even a retained austenite phase is tolerable as long as the area ratio of these phases with respect to the entire microstructure is 5 % or less.
  • a steel sheet has a metal structure of substantially ferrite single phase
  • the metal structure remains as substantially ferrite single phase even when the steel sheet is heated to a temperature range of 400 °C to 700 °C (warm-forming temperature range).
  • the aforementioned steel sheet may show an increase in ductility as it is heated, achieving good total elongation in the warm-forming temperature range.
  • the forming process is conducted in connection with recovery of dislocation, and consequently, with little reduction in ductility during warm forming.
  • the steel sheet does not show any microstructural changes even when cooled to room temperature after warm forming, it maintains the metal structure of substantially ferrite single phase and exhibits excellent ductility.
  • Average grain size of ferrite 1 ⁇ m or more
  • ferrite For ferrite having an average grain size of less than 1 ⁇ m, crystal grains tend to grow during warm forming, with the result that the material properties of a press-formed part after warm forming considerably differ from those observed before warm forming, reducing the stability of the steel sheet as a material. Therefore, ferrite preferably has an average grain size of 1 ⁇ m or more.
  • ferrite if ferrite has an excessively large, average grain size over 15 ⁇ m, it is not possible to achieve strengthening through grain refinement of the microstructure, which makes it difficult to ensure a desired strength of the steel sheet. Therefore, ferrite preferably has an average grain size of 15 ⁇ m or less, and more preferably 12 ⁇ m or less.
  • the finisher delivery temperature is preferably set to be 840 °C or higher.
  • Average particle size of carbides in the ferrite crystal grains 10 nm or less
  • the strength of the steel sheet may be increased by allowing fine carbides having an average particle size of 10 nm or less to be precipitated in the ferrite crystal grains.
  • the average particle size of the carbides is more than 10 nm, it is difficult to obtain the aforementioned high tensile strength and/or yield ratio.
  • the average particle size of the carbides is more preferably 7 nm or less.
  • Examples of the fine carbides include Ti carbides, and furthermore, V carbides, Mo carbides, W carbides, Nb carbides, Zr carbides, and Hf carbides. These carbides do not undergo coarsening and the average particle size thereof remains 10 nm or less, as long as the heating temperature of the steel sheet is held at 700 °C or lower. The coarsening of the carbides is thus suppressed even when the steel sheet is heated to a warm-forming temperature range of 400 °C to 700 °C for warm forming, with the result that the steel sheet will not show a considerable reduction in its strength after cooled to room temperature following the warm forming process.
  • the aforementioned steel sheet may comprise a coating or plating layer, such as a hot dip galvanized layer.
  • a coating or plating layer include an electroplated layer, an electroless-plated layer, a hot-dipped layer, and so on.
  • a galvannealed layer may also be used.
  • the steel sheet that can preferably be used in the warm press forming method according to the present invention is obtained by heating a steel material, then subjecting the steel material to hot rolling including rough rolling and finish rolling, and subsequently coiling the steel material to obtain a hot rolled steel sheet.
  • the method for manufacturing a steel raw material preferably includes, without any particular limitation: preparing a molten steel having the aforementioned composition by a well-known steelmaking method, such as a converter and an electric furnace; subjecting the molten steel to optional secondary refining in a vacuum degassing furnace; and casting the molten steel to obtain a steel raw material, such as slab, by a well-known casting method, such as a continuous casting. Note that the continuous casting is preferred in terms of productivity and quality.
  • Heating temperature of steel raw material 1100 °C to 1350 °C
  • Coarse carbides fail to be dissolved if the heating temperature of the steel raw material is below 1100 °C, and consequently fewer fine carbides are dispersed and precipitated in the resulting steel sheet, which makes it difficult to ensure a high strength as desired.
  • the heating temperature of the steel raw material is above 1350 °C, oxidation progresses so much as to form oxide scales during hot rolling and to deteriorate the surface texture of the steel sheet, thereby lowering the warm formability of the steel sheet. Therefore, the heating temperature of the steel raw material is preferably set in the range of 1100 °C to 1350 °C. A more preferable range is 1150 °C to 1300 °C.
  • Finisher delivery temperature 840 °C or higher
  • the finisher delivery temperature is below 840 °C
  • the microstructure contains extended ferrite grains and ends up with a mixed-grain-size microstructure in which individual ferrite grains are greatly different in grain size, with the result that the strength of the steel sheet significantly decreases.
  • a finisher delivery temperature below 840 °C results in excessive strain energy being stored in the steel sheet during the rolling process, which makes it difficult to obtain a microstructure containing ferrite grains having an average grain size of 1 ⁇ m or more. Therefore, the finisher delivery temperature is preferably set to be 840 °C or higher, and more preferably 860 °C or higher.
  • the resulting hot rolled steel sheet is subjected to forced cooling. If more than three seconds elapse before the forced cooling is initiated after completion of the hot rolling, a large amount of carbides are subject to strain-induced precipitation, which makes it difficult to ensure desired precipitation of fine carbides. Therefore, the forced cooling is preferably initiated within three seconds after completion of the hot rolling, and more preferably within two seconds.
  • Average cooling rate from the start to the end of cooling 30 °C/s or higher
  • the aforementioned forced cooling after the hot rolling is preferably performed at an average cooling rate of 30 °C/s or higher to rapidly cool the steel sheet to a predetermined temperature.
  • the average cooling rate is more preferably 50 °C/s or higher.
  • a cooling stop temperature is set such that a coiling temperature eventually falls within a target temperature range, taking into account the temperature drop that would occur in the steel sheet during a period from the end of cooling to the start of coiling. That is, since the steel sheet experiences a drop in temperature as it is air cooled after the end of cooling, the cooling stop temperature is normally set to be approximately equal to the temperature in the range of coiling temperature + 5 °C to + 10 °C.
  • Coiling temperature 500 °C to 700 °C
  • a coiling temperature below 500 °C results in an insufficient amount of carbides being precipitated in the steel sheet for providing the steel sheet with as high strength as desired.
  • a coiling temperature above 700 °C induces coarsening of precipitated carbides, which also makes it difficult to provide the steel sheet with as high strength as desired. Therefore, the coiling temperature is preferably set in the range of 500 °C to 700 °C, and more preferably in the range of 550 °C to 680 °C.
  • the resulting hot rolled steel sheet may be subjected to a coating or plating process using a well-known method to form a coating or plating layer on its surface.
  • the coating or plating layer is preferably a hot-dip galvanized layer, a galvannealed layer, an electroplated layer, or the like.
  • the preferred steel sheet has the following mechanical properties:
  • the warm press forming method according to the present invention is applied to a steel sheet having a tensile strength at room temperature of 440 MPa or more
  • the aforementioned manufacturing method may be used to obtain a steel sheet having TS 1 of 780 MPa or more and a yield ratio at room temperature of 0.85 or more.
  • TS 1 represents a tensile strength at room temperature and "room temperature” refers to a temperature of (22 ⁇ 5) °C.
  • the deformation resistance of the steel sheet is not sufficiently reduced at the time of warm forming and accordingly increased load (press load) is required for warm forming, leading to a shortened die life.
  • the body size of the processing machine (press machine) must be necessarily increased for applying a large load (press load). As the body size of the processing machine (press machine) increases, it takes a longer time to transfer a steel sheet heated to a warm forming temperature to a processing machine, which causes a temperature drop in the blank and accordingly makes it difficult to perform warm forming at a desired temperature range.
  • shape fixability is not improved sufficiently, and consequently the effect to be obtained by warm forming is reduced.
  • the yield strength YS 2 in the warm-forming temperature range of 400 °C to 700 °C is preferably set to be 80 % or less, and more preferably 70 % or less of the yield strength YS 1 at room temperature.
  • the total elongation El 2 in the warm-forming temperature range of 400 °C to 700 °C is preferably set to be 1.1 times or more, and more preferably 1.2 times or more the total elongation El 1 at room temperature.
  • a steel sheet which exhibits the following mechanical properties in addition to the above after being formed into a press-formed part, may more preferably be used in the warm press forming method according to the present invention.
  • Yield strength YS 3 at room temperature and total elongation El 3 at room temperature of a press-formed part 80 % or more of the yield strength YS 1 at room temperature and the total elongation El 1 at room temperature of the material steel sheet prior to press forming
  • the strength and total elongation of the resulting member after warm forming are insufficient. If such a steel sheet is subjected to warm press forming to produce an automobile component of desired shape, the resulting component offers insufficient crash worthiness upon crash of the automobile, resulting in reduced reliability as an automobile component.
  • a press-formed part has a yield strength YS 3 at room temperature and a total elongation El 3 at room temperature that are 80 % or more, and more preferably 90 % or more of the yield strength YS 1 at room temperature and the total elongation El 1 at room temperature of the material steel sheet prior to press forming.
  • the steel sheets were heated in an electric furnace.
  • the in-furnace time was set to be 300 seconds so that each blank can be heated in the furnace, resulting in a uniform temperature distribution throughout the blank.
  • the heated blanks were then removed from the furnace and fed into a press machine after a transfer time of 10 seconds, respectively, where the blanks were subjected to forming processes with different holding times at the press bottom dead point as shown in Table 1.
  • the temperature difference between flange portions and other portions of each of the formed panels was measured. That is, the temperature was measured in each panel at six points (indicated by "X" in FIG. 5(a) ) in flange portions and five points in other portions (indicated by "Y” in FIG. 5(a) ) using a contactless thermometer, and the difference between the average temperature of the X points and the average temperature of the Y points was defined as the difference in average temperature among the flange portions and the other portions.
  • a servo press was used as a press machine, where the pressing speed was set to be 15 spm (strokes per minute, which represents the number of parts that can be formed in one minute plus any additional time, if applicable, taken to hold the parts at the press bottom dead point).
  • the formed panels were air cooled for a sufficiently long period of time, after which, regarding the cross sectional shape of each center pillar upper press panel as shown in FIG. 5(b) , measurements were made with a laser displacement sensor of the amount of geometric changes a made to the edges of each panel until the end of air cooling, in relation to the reference panel shape (which is the shape the panel took when it was removed from the die immediately after the press forming process). The measurement results are also shown in Table 1.
  • each of steel Nos. 1, 2, 5 to 9 of inventive examples in which steel sheets were held at the press bottom dead point for one second or more, yielded good dimensional accuracy such that the difference in average temperature among flange portions and other portions of each press-formed part was kept within 150 °C and the amount of geometric changes a was 1.0 mm or less.
  • the warm press forming method according to the present invention may suppress the difference in average temperature among flange portions and other portions of a panel, and thereby reduce the amount of geometric changes made to the panel from the time immediately after press forming until the end of air cooling, thereby providing the press-formed part with significantly improved dimensional accuracy.
  • Molten steels having the chemical compositions shown in Table 2 were prepared by steelmaking in a converter, and subjected to continuous casting to obtain slabs (steel raw materials).
  • the slabs (steel raw materials) were heated to the heating temperatures shown in Table 3, then subjected to soaking, rough rolling, finish rolling under the hot rolling conditions shown in Table 3, cooling, and subsequent coiling to obtain hot rolled steel sheets (sheet thickness: 1.6 mm).
  • each of the steel sheets a, i, k, m was heated to 700 °C in a continuous galvanizing line and immersed in a hot-dip galvanizing bath at a liquid temperature of 460 °C to form a hot-dip galvanized layer on the surfaces of the steel sheet, and the hot-dip galvanized layer thus obtained was subjected to alloying treatment at 530 °C to form a galvannealed layer.
  • the coating weight was set to be 45 g/m 2 for each steel sheet.
  • test pieces were collected from the hot rolled steel sheets thus obtained and analyzed by microstructure observation, precipitation observation, and tensile tests. The analysis was carried out as follows.
  • Test pieces were collected from the obtained hot rolled steel sheets for microstructure observation. Each test piece was polished and etched (etching solution: 5 % nital solution) at its cross section parallel to the rolling direction (L-section), and then its center part in the sheet thickness direction was observed and imaged in ten fields of view under a scanning electron microscope (at magnification of x400). The micrographs thus obtained were analyzed using an image processing technique to identify the microstructure and to measure the microstructure proportion and the average grain size of each phase.
  • the obtained micrographs were used to distinguish ferrite phase from other phases so as to measure the area of the ferrite phase, thereby determining an area ratio of the ferrite phase to the entire fields of view being observed. While the ferrite phase is observed with smoothly curved grain boundaries with no corrosion marks appeared in the grains, any grain boundaries appeared in linear form were construed as part of the ferrite phase.
  • the obtained micrographs were also used to determine the average grain size of ferrite by a cutting method in conformity with ASTM E 112-10.
  • test pieces were collected from the center portions in the sheet thickness direction of the obtained hot rolled steel sheets, and subjected to mechanical and chemical polish to obtain thin films for observation under a transmission electron microscope (TEM).
  • the thin films thus obtained were observed under a TEM (at magnification of ⁇ 120,000) for precipitates (carbides).
  • Measurements were made of the particle size of 100 or more carbides to determine an arithmetic mean value thereof, which was defined as the average particle size of carbides in each steel sheet. Note that coarse cementite and nitride particles greater than 1 ⁇ m in diameter were excluded from the measurements.
  • JIS No. 13B tensile test pieces were collected from the obtained hot rolled steel sheets with a direction orthogonal to the rolling direction being the tensile direction, in accordance with JIS Z 2201 (1998 ).
  • the collected test pieces were subjected to tensile tests in accordance with JIS G 0567 (1998 ) to measure mechanical properties (yield strength YS 1 , tensile strength TS 1 , total elongation El 1 ) at room temperature (22 ⁇ 5 °C) and high-temperature mechanical properties (yield strength YS 2 , tensile strength TS 2 , total elongation El 2 ) at temperatures shown in Table 4.
  • Table 3 and Table 4 list the test results (1) to (3).
  • each of steel Nos. 17 to 42 of inventive examples yielded good dimensional accuracy such that the difference in average temperature between flange portions and other portions was kept within 150 °C and the amount of geometric changes a was 1.0 mm or less.
  • steel Nos. 17 to 42 of inventive examples yielded good dimensional accuracy such that the difference in average temperature between flange portions and other portions was kept within 150 °C and the amount of geometric changes a was 1.0 mm or less.
  • steel Nos. 17 to 42 of inventive examples yielded good dimensional accuracy such that the difference in average temperature between flange portions and other portions was kept within 150 °C and the amount of geometric changes a was 1.0 mm or less.
  • steel Nos. 17 to 42 of inventive examples yielded good dimensional accuracy such that the difference in average temperature between flange portions and other portions was kept within 150 °C and the amount of geometric changes a was 1.0 mm or less.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)
  • Heat Treatment Of Articles (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)

Claims (4)

  1. Warmpress-Formverfahren zum Formen eines Stahlblechs, das eine Zugfestigkeit von 440 MPa oder mehr aufweist, zu einem pressgeformten Teil, das Flanschabschnitte und andere Abschnitte beinhaltet, durch Pressformen, wobei das Verfahren umfasst:
    Erhitzen des Stahlblechs auf einen Temperaturbereich von 400 °C bis höchstens 700 °C; und
    anschließend Pressformen des erhitzten Stahlblechs unter Benutzen von Ziehformen, um ein pressgeformtes Teil zu erhalten, wobei das Stahlblech drei Sekunde bis nicht mehr als fünf Sekunden lang an einem unteren Totpunkt der Presse in dem Gesenk gehalten wird, zum Zeitpunkt des Pressformens unter Benutzen von Ziehformen, und
    wobei eine Differenz der durchschnittlichen Temperatur zwischen Flanschabschnitten und anderen Abschnitten des pressgeformten Teils sofort nach dem Ziehformen innerhalb 150 °C gehalten wird, indem das Stahlblech am unteren Totpunkt der Presse in dem Gesenk gehalten wird.
  2. Warmpress-Formverfahren nach Anspruch 1, wobei das pressgeformte Teil eine Zugfestigkeit von 80 % bis 110 % einer Zugfestigkeit des Stahlblechs vor dem Pressformen aufweist.
  3. Warmpress-Formverfahren nach einem von Anspruch 1 bis 2, wobei das Stahlblech eine chemische Zusammensetzung aufweist, die in Masse-% enthält:
    C: 0,015 % bis 0,16 %,
    Si: 0,2 % oder weniger,
    Mn: 1,8 % oder weniger,
    P: 0,035 % oder weniger,
    S: 0,01 % oder weniger,
    Al: 0,1 % oder weniger,
    N: 0,01 % oder weniger und
    Ti: 0,13 % bis 0,25 %,
    mit der Maßgabe, dass ein Verhältnis erfüllt ist, das durch Ausdruck (1) unten definiert ist, und wahlweise in Masse-% mindestens eines, ausgewählt aus
    V: 1,0 % oder weniger,
    Mo: 0,5 % oder weniger,
    W: 1,0 % oder weniger,
    Nb: 0,1 % oder weniger,
    Zr: 0,1 % oder weniger und
    Hf: 0,1 % oder weniger,
    mit der Maßgabe, dass ein Verhältnis erfüllt ist, das durch Ausdruck (1)' definiert ist,
    B: 0,003 % oder weniger,
    mindestens eines, ausgewählt aus Mg: 0,2 % oder weniger, Ca: 0,2 % oder weniger, Y: 0,2 % oder weniger und Seltenerdmetall: 0,2 % oder weniger,
    mindestens eines, ausgewählt aus Sb: 0,1 % oder weniger, Cu: 0,5 % oder weniger und Sn: 0,1 % oder weniger,
    mindestens eines, ausgewählt aus Ni: 0,5 % oder weniger und Cr: 0,5 % oder weniger und
    mindestens eines, ausgewählt aus O, Se, Te, Po, As, Bi, Ge, Pb, Ga, In, Tl, Zn, Cd, Hg, Ag, Au, Pd, Pt, Co, Rh, Ir, Ru, Os, Tc, Re, Ta, Be und Sr, in einer Gesamtmenge von 2,0 % oder weniger,
    wobei der Rest Fe und zufällige Verunreinigungen beinhaltet und
    wobei das Stahlblech ein Gefüge aufweist, das eine Ferritphase zu 95 % oder mehr auf einer Flächenverhältnisbasis in Bezug auf das gesamte Gefüge enthält, Ferritkristallkörner, welche die Ferritphase bilden, eine durchschnittliche Korngröße von 1 µm oder mehr aufweisen und Carbide, die eine durchschnittliche Partikelgröße von 10 nm oder weniger aufweisen, in den Ferritkristallkörnern dispergiert und ausgeschieden sind.
    2,00 ≥ % C / 12 / % Ti / 48 ≥ 1,05
    Figure imgb0009
     2,00 ≥ % C / 12 / % Ti / 48 + % V / 51 + % W / 184 + % Mo / 96 + % Nb / 93 + % Zr / 91 + % Hf / 179 ≥ 1,05
    Figure imgb0010
     wobei [%M] den Gehalt in Masse-% von Element M angibt.
  4. Warmpress-Formverfahren nach einem von Anspruch 1 bis 3, wobei das Stahlblech eine Beschichtung oder Überzugsschicht auf einer Fläche davon umfasst.
EP13757922.3A 2012-03-06 2013-03-04 Heisspressformverfahren und karosseriekomponenten eines kraftfahrzeugs Active EP2823905B2 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012048725 2012-03-06
PCT/JP2013/001316 WO2013132821A1 (ja) 2012-03-06 2013-03-04 温間プレス成形方法および自動車骨格部品

Publications (4)

Publication Number Publication Date
EP2823905A1 EP2823905A1 (de) 2015-01-14
EP2823905A4 EP2823905A4 (de) 2015-07-01
EP2823905B1 EP2823905B1 (de) 2017-01-11
EP2823905B2 true EP2823905B2 (de) 2020-03-25

Family

ID=49116317

Family Applications (1)

Application Number Title Priority Date Filing Date
EP13757922.3A Active EP2823905B2 (de) 2012-03-06 2013-03-04 Heisspressformverfahren und karosseriekomponenten eines kraftfahrzeugs

Country Status (6)

Country Link
US (1) US20150064052A1 (de)
EP (1) EP2823905B2 (de)
JP (1) JPWO2013132821A1 (de)
KR (1) KR101630557B1 (de)
CN (1) CN104159681B (de)
WO (1) WO2013132821A1 (de)

Families Citing this family (45)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5541263B2 (ja) * 2011-11-04 2014-07-09 Ｊｆｅスチール株式会社 加工性に優れた高強度熱延鋼板およびその製造方法
CN103789631A (zh) * 2014-01-16 2014-05-14 安徽省杨氏恒泰钢管扣件加工有限公司 一种长距离输送管线用钢管材料及其制备方法
CN104195445A (zh) * 2014-09-02 2014-12-10 青岛永通电梯工程有限公司 一种合金钢
JP6152836B2 (ja) * 2014-09-25 2017-06-28 Ｊｆｅスチール株式会社 熱間プレス成形品の製造方法
KR20160045177A (ko) * 2014-10-16 2016-04-27 현대자동차주식회사 초고장력 강판의 온간 성형 방법
CN105385960A (zh) * 2015-11-26 2016-03-09 佛山市高明区杨和金属材料专业镇技术创新中心 一种热轧板的生产工艺
CN105463345A (zh) * 2015-12-11 2016-04-06 滁州市品诚金属制品有限公司 一种铝锰铁合金
CN105349912A (zh) * 2015-12-16 2016-02-24 常熟市凯波冶金建材机械设备厂 燃气轮机用轴承座
CN105543720A (zh) * 2015-12-18 2016-05-04 常熟市恒仕达电器有限公司 商用制冰机
CN105438637A (zh) * 2015-12-24 2016-03-30 常熟市新冶机械制造有限公司 摩根线材打捆机
CN105369163A (zh) * 2015-12-24 2016-03-02 常熟市新冶机械制造有限公司 线材轧机用固定剪刃
CN105543656A (zh) * 2015-12-24 2016-05-04 常熟市新冶机械制造有限公司 森德斯线材打捆机
CN105568182A (zh) * 2015-12-24 2016-05-11 常熟市新冶机械制造有限公司 打包头总装配
CN105543724A (zh) * 2015-12-24 2016-05-04 常熟市新冶机械制造有限公司 液压元件
CN105506447A (zh) * 2015-12-24 2016-04-20 常熟市新冶机械制造有限公司 打包头扭结装置
CN105543723A (zh) * 2015-12-24 2016-05-04 常熟市新冶机械制造有限公司 线道装置
CN105369165A (zh) * 2015-12-24 2016-03-02 常熟市新冶机械制造有限公司 棒材打捆机零配件
CN105385964A (zh) * 2015-12-24 2016-03-09 常熟市新冶机械制造有限公司 活动剪刃
CN105483540A (zh) * 2015-12-24 2016-04-13 常熟市新冶机械制造有限公司 吐丝管
CN105543657A (zh) * 2015-12-24 2016-05-04 常熟市新冶机械制造有限公司 线材轧机用保持架
CN105349917A (zh) * 2015-12-24 2016-02-24 常熟市新冶机械制造有限公司 线材轧机用抛油环
CN105506516A (zh) * 2015-12-24 2016-04-20 常熟市新冶机械制造有限公司 密封元件
CN105483569A (zh) * 2015-12-24 2016-04-13 常熟市新冶机械制造有限公司 固定剪刃
CN105420640A (zh) * 2015-12-24 2016-03-23 常熟市新冶机械制造有限公司 线材轧机用活动剪刃
CN105369164A (zh) * 2015-12-24 2016-03-02 常熟市新冶机械制造有限公司 线材轧机用锥套
CN105460394A (zh) * 2015-12-24 2016-04-06 常熟市新冶机械制造有限公司 线材打捆机零配件
CN105603314A (zh) * 2016-02-17 2016-05-25 柳州市乾阳机电设备有限公司 钢材
CN105695865A (zh) * 2016-02-17 2016-06-22 柳州市乾阳机电设备有限公司 耐腐蚀钢材
CN106438327A (zh) * 2016-08-31 2017-02-22 宁波钱湖石油设备有限公司 一种往复泵动力端
CN106438261A (zh) * 2016-08-31 2017-02-22 宁波钱湖石油设备有限公司 一种往复泵动力装置
CN106591699A (zh) * 2016-12-04 2017-04-26 丹阳市宸兴环保设备有限公司 一种车体防锈金属材料
CN106480352A (zh) * 2016-12-04 2017-03-08 丹阳市宸兴环保设备有限公司 一种耐高温金属材料
CN106480382A (zh) * 2016-12-04 2017-03-08 丹阳市宸兴环保设备有限公司 一种耐磨抗冲击金属材料及其制备方法
CN106734576B (zh) * 2016-12-28 2019-04-23 马鞍山蓝科再制造技术有限公司 一种弹簧托架的冷冲压模具
CN107326291A (zh) * 2017-05-26 2017-11-07 太仓明仕金属制造有限公司 一种金属五金材料
CN107245660A (zh) * 2017-05-27 2017-10-13 太仓源壬金属科技有限公司 一种耐磨性汽车零部件用钢
CN107058888A (zh) * 2017-05-27 2017-08-18 苏州铭晟通物资有限公司 一种金属五金钢材
CN107475636A (zh) * 2017-08-09 2017-12-15 安徽省无为煤矿机械制造有限公司 一种煤矿机械用无缝钢管材料
CN107739988A (zh) * 2017-08-30 2018-02-27 宁波亿润汽车零部件有限公司 一种汽车排气管支架及其制备方法
CN107740000A (zh) * 2017-08-30 2018-02-27 宁波亿润汽车零部件有限公司 一种安全气囊电子控制单元支架及其制备方法
RU2663952C1 (ru) * 2017-12-19 2018-08-13 Юлия Алексеевна Щепочкина Сплав на основе железа
JP6981487B2 (ja) * 2020-02-25 2021-12-15 Ｊｆｅスチール株式会社 プレス成形方法及びプレス成形品の形状評価方法
JP7475213B2 (ja) 2020-06-23 2024-04-26 日鉄ステンレス株式会社 金属板のプレス成形方法
CN114505389B (zh) * 2022-02-17 2023-12-22 北京理工大学重庆创新中心 一种利用机构补偿环境温度的高强钢热冲压成形优化方法
CN114713672B (zh) * 2022-05-09 2024-04-12 四川攀钢嘉德精工科技有限公司 钛板连续辊压温成型工艺

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1403388A1 (de) † 2002-09-26 2004-03-31 ThyssenKrupp Stahl AG Verfahren zum Herstellen von Produkten durch Umformen bei erhöhten Temperaturen
US20050257862A1 (en) † 2004-05-21 2005-11-24 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) Production method of warm- or hot-formed product
DE102007008117B3 (de) † 2007-02-19 2008-08-21 Voestalpine Anarbeitung Gmbh Verfahren und Vorrichtung zum temperierten Umformen von warmgewalztem Stahlmaterial
DE102008020757A1 (de) † 2007-04-30 2008-11-06 Volkswagen Ag Verfahren zur Umformung von Blechwerkstücken aus Eisen-Mangan-Stahl
DE102008050315A1 (de) † 2008-10-02 2009-05-20 Daimler Ag Umformen von Martensit-haltigen Stahlblechen
JP2010188393A (ja) † 2009-02-19 2010-09-02 Sumitomo Metal Ind Ltd 鋼板のプレス成形方法
JP2011230189A (ja) † 2010-04-09 2011-11-17 Jfe Steel Corp 温間プレス成形方法
WO2011162412A1 (ja) † 2010-06-25 2011-12-29 Ｊｆｅスチール株式会社 伸びフランジ性に優れた高強度熱延鋼板およびその製造方法

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62182241A (ja) * 1986-02-06 1987-08-10 Hitachi Metals Ltd 締付け、整形用部材およびその製造方法
TW565621B (en) * 2000-05-26 2003-12-11 Jfe Steel Corp Cold-rolled steel sheet and galvanized steel sheet having strain age hardenability property and method for producing the same
JP4506005B2 (ja) * 2001-03-01 2010-07-21 住友金属工業株式会社 温間成形用高張力鋼板およびその成形法
JP2003053446A (ja) * 2001-08-15 2003-02-26 Nippon Steel Corp 自動車用構造部材の成形方法
JP2003113442A (ja) * 2001-10-05 2003-04-18 Sumitomo Metal Ind Ltd 温間成形性にすぐれた高張力鋼板
JP2005205416A (ja) 2004-01-20 2005-08-04 Nissan Motor Co Ltd 熱間プレス成形方法および熱間プレス成形型
JP4494834B2 (ja) * 2004-03-16 2010-06-30 新日本製鐵株式会社 熱間成形方法
JP2006068797A (ja) * 2004-09-06 2006-03-16 Nippon Steel Corp 耐水素脆化特性に優れた高強度鋼板のホットプレス成形方法
JP4506476B2 (ja) * 2005-01-17 2010-07-21 Ｊｆｅスチール株式会社 温間成形に適した冷延鋼板およびその製造方法
JP4575799B2 (ja) * 2005-02-02 2010-11-04 新日本製鐵株式会社 成形性に優れたホットプレス高強度鋼製部材の製造方法
JP4609107B2 (ja) * 2005-02-22 2011-01-12 Ｊｆｅスチール株式会社 高強度部材の製造方法
JP5344454B2 (ja) * 2005-11-21 2013-11-20 独立行政法人物質・材料研究機構 温間加工用鋼、その鋼を用いた温間加工方法、およびそれにより得られる鋼材ならびに鋼部品
JP5347393B2 (ja) * 2008-09-12 2013-11-20 Ｊｆｅスチール株式会社 延性に優れたホットプレス部材、そのホットプレス部材用鋼板、およびそのホットプレス部材の製造方法
JP5609223B2 (ja) * 2010-04-09 2014-10-22 Ｊｆｅスチール株式会社 温間加工性に優れた高強度鋼板およびその製造方法
JP5754279B2 (ja) * 2011-07-20 2015-07-29 Ｊｆｅスチール株式会社 温間成形用高強度鋼板およびその製造方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1403388A1 (de) † 2002-09-26 2004-03-31 ThyssenKrupp Stahl AG Verfahren zum Herstellen von Produkten durch Umformen bei erhöhten Temperaturen
US20050257862A1 (en) † 2004-05-21 2005-11-24 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) Production method of warm- or hot-formed product
DE102007008117B3 (de) † 2007-02-19 2008-08-21 Voestalpine Anarbeitung Gmbh Verfahren und Vorrichtung zum temperierten Umformen von warmgewalztem Stahlmaterial
DE102008020757A1 (de) † 2007-04-30 2008-11-06 Volkswagen Ag Verfahren zur Umformung von Blechwerkstücken aus Eisen-Mangan-Stahl
DE102008050315A1 (de) † 2008-10-02 2009-05-20 Daimler Ag Umformen von Martensit-haltigen Stahlblechen
JP2010188393A (ja) † 2009-02-19 2010-09-02 Sumitomo Metal Ind Ltd 鋼板のプレス成形方法
JP2011230189A (ja) † 2010-04-09 2011-11-17 Jfe Steel Corp 温間プレス成形方法
WO2011162412A1 (ja) † 2010-06-25 2011-12-29 Ｊｆｅスチール株式会社 伸びフランジ性に優れた高強度熱延鋼板およびその製造方法

Non-Patent Citations (8)

* Cited by examiner, † Cited by third party
Title
HELLER ET AL: "The Conference Steels in Cars and Trucks", 2005, VERLAG STAHLEISEN, article "ThyssenKrupp Stahl - Semi-hot forming as an Advantage to Hot forming", pages: 564, XP055431217 †
JIS G 3135, 11 July 1986 †
KOLECK, R. ET AL: "Manufaturing methods for safety and structural body parts for lightweight body design", PROCEEDINGS IDDRG INTERNATIONAL DEEP DRAWING RESEARCH GROUP 2004 CONFERENCE, FORMING THE FUTURE, VDEH, pages 167 - 1173 †
LENZE F-J: "Herstellung von Karosseriebauteilen aus warmumgeformten h¦chfesten Stahlwerkstoffe", EFB TAGUNGSBAND, vol. 25, 2005, pages 53 - 61, XP009098694 †
MORI ET AL: "Warm and Hot Stamping of Ultra High Tensile Strength Steel Sheets Using Resistance Heating", CIRP ANNALS, vol. 54, no. 1, 2005, pages 209 - 212, XP022122553 †
SCHIESSL, G. ET AL: "Manufacturing a roof frame from ultrahigh-strength steel materials by hot stamping", PROCEEDINGS IDDRG INTERNATIONAL DEEP DRAWING RESEARCH GROUP 2004 CONFERENCE, FORMING THE FUTURE, VDEH, pages 158 - 166 †
SEIJIRO MAKI: "Resistance Heating Characteristics of High-Strength Steel Sheet Blank for Hot Press Forming", KEY ENGINEERING MATERIALS, vol. 340-341, 1 January 2007 (2007-01-01), pages 749 - 754, XP055431089 †
YANAGIMOTO ET AL: "Springback of High-Strength Steel after Hot and Warm Sheet Formings", CIRP ANNALS, vol. 54, no. 1, 2005, pages 213 - 216, XP022122554 †

Also Published As

Publication number Publication date
CN104159681B (zh) 2016-02-24
US20150064052A1 (en) 2015-03-05
EP2823905A4 (de) 2015-07-01
WO2013132821A1 (ja) 2013-09-12
EP2823905A1 (de) 2015-01-14
KR20140122266A (ko) 2014-10-17
JPWO2013132821A1 (ja) 2015-07-30
KR101630557B1 (ko) 2016-06-14
EP2823905B1 (de) 2017-01-11
CN104159681A (zh) 2014-11-19

Similar Documents

Publication Publication Date Title
EP2823905B2 (de) Heisspressformverfahren und karosseriekomponenten eines kraftfahrzeugs
EP2823904B1 (de) Warmformpressmethode für stahl
KR102253720B1 (ko) 핫 프레스 부재 및 그 제조 방법
CN110114500B (zh) 冲击特性优异的热压成型用镀覆钢板、热压成型部件及它们的制造方法
EP3214199B1 (de) Hochfestes stahlblech, hochfestes feuerverzinktes stahlblech, hochfestes feuerverzinktes aluminiumbeschichtetes stahlblech und hochfestes elektrogalvanisiertes stahlblech sowie verfahren zur herstellung davon
KR101621639B1 (ko) 강판, 도금 강판 및 그들의 제조 방법
JP6260676B2 (ja) ホットプレス用鋼板およびその製造方法、ならびにホットプレス部材およびその製造方法
KR101479391B1 (ko) 형상 동결성이 우수한 냉연 박강판 및 그 제조 방법
EP2937433B1 (de) Hochfestes kaltgewalztes stahlblech mit hohem ertrag und verfahren zur herstellung davon
WO2007129676A1 (ja) 熱間プレス成形鋼板部材およびその製造方法
EP2816129B1 (de) Kaltgewalztes stahlblech, plattiertes stahlblech, und herstellungsverfahren dafür
EP3564401B1 (de) Verfahren zur herstellung eines heisspressformteils
JP5126844B2 (ja) 熱間プレス用鋼板およびその製造方法ならびに熱間プレス鋼板部材の製造方法
JP2007002276A (ja) 高強度鋼板およびその製造方法
CN110582588B (zh) 用于制造轻质结构件的高可成形性钢板及制造方法
JP7277837B2 (ja) ホットスタンプ成形体
EP3992314A1 (de) Stahlblech
JP2017179588A (ja) ホットプレス部材およびその製造方法
JP6443375B2 (ja) ホットプレス部材およびその製造方法
CN116867918A (zh) 热压成形体
WO2021141006A1 (ja) 鋼板およびその製造方法
EP4303334A1 (de) Stahlplatte
WO2023073411A1 (en) Cold rolled and heat treated steel sheet and a method of manufacturing thereof
WO2023189183A1 (ja) ホットスタンプ成形体
WO2023189174A1 (ja) ホットスタンプ成形体

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20140929

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAX Request for extension of the european patent (deleted)
RA4 Supplementary search report drawn up and despatched (corrected)

Effective date: 20150601

17Q First examination report despatched

Effective date: 20160208

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

RIC1 Information provided on ipc code assigned before grant

Ipc: C22C 38/28 20060101ALI20160707BHEP

Ipc: B21K 7/12 20060101ALI20160707BHEP

Ipc: B21D 22/20 20060101AFI20160707BHEP

Ipc: C22C 38/50 20060101ALI20160707BHEP

Ipc: C23C 2/28 20060101ALI20160707BHEP

Ipc: C22C 38/60 20060101ALI20160707BHEP

Ipc: C21D 9/46 20060101ALI20160707BHEP

Ipc: C23C 2/06 20060101ALI20160707BHEP

Ipc: C21D 9/00 20060101ALI20160707BHEP

Ipc: C22C 38/00 20060101ALI20160707BHEP

Ipc: C22C 38/02 20060101ALI20160707BHEP

Ipc: C22C 38/20 20060101ALI20160707BHEP

Ipc: C21D 1/673 20060101ALI20160707BHEP

Ipc: C22C 38/24 20060101ALI20160707BHEP

Ipc: C22C 38/12 20060101ALI20160707BHEP

Ipc: B21D 53/88 20060101ALI20160707BHEP

Ipc: C21D 8/02 20060101ALI20160707BHEP

Ipc: C22C 38/14 20060101ALI20160707BHEP

Ipc: B21J 1/06 20060101ALI20160707BHEP

Ipc: C22C 38/44 20060101ALI20160707BHEP

INTG Intention to grant announced

Effective date: 20160802

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 860790

Country of ref document: AT

Kind code of ref document: T

Effective date: 20170115

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602013016492

Country of ref document: DE

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 5

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20170111

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 860790

Country of ref document: AT

Kind code of ref document: T

Effective date: 20170111

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170412

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170511

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170411

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170411

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170511

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

REG Reference to a national code

Ref country code: DE

Ref legal event code: R026

Ref document number: 602013016492

Country of ref document: DE

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PLAX Notice of opposition and request to file observation + time limit sent

Free format text: ORIGINAL CODE: EPIDOSNOBS2

26 Opposition filed

Opponent name: THYSSENKRUPP STEEL EUROPE AG

Effective date: 20171011

Opponent name: VOESTALPINE STAHL GMBH

Effective date: 20171011

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170304

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 6

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170331

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170331

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170304

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20170331

PLBB Reply of patent proprietor to notice(s) of opposition received

Free format text: ORIGINAL CODE: EPIDOSNOBS3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170304

PLAB Opposition data, opponent's data or that of the opponent's representative modified

Free format text: ORIGINAL CODE: 0009299OPPO

PLAB Opposition data, opponent's data or that of the opponent's representative modified

Free format text: ORIGINAL CODE: 0009299OPPO

R26 Opposition filed (corrected)

Opponent name: VOESTALPINE STAHL GMBH

Effective date: 20171011

R26 Opposition filed (corrected)

Opponent name: VOESTALPINE STAHL GMBH

Effective date: 20171011

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20130304

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

PUAH Patent maintained in amended form

Free format text: ORIGINAL CODE: 0009272

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: PATENT MAINTAINED AS AMENDED

27A Patent maintained in amended form

Effective date: 20200325

AK Designated contracting states

Kind code of ref document: B2

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: DE

Ref legal event code: R102

Ref document number: 602013016492

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170111

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 602013016492

Country of ref document: DE

Representative=s name: HL KEMPNER PATENTANWAELTE, SOLICITORS (ENGLAND, DE

Ref country code: DE

Ref legal event code: R082

Ref document number: 602013016492

Country of ref document: DE

Representative=s name: HL KEMPNER PATENTANWALT, RECHTSANWALT, SOLICIT, DE

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20230208

Year of fee payment: 11

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230512

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20240130

Year of fee payment: 12

Ref country code: GB

Payment date: 20240201

Year of fee payment: 12