[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

EP3691889A1 - Hot-forming composite material, production thereof, component, and use thereof - Google Patents

Hot-forming composite material, production thereof, component, and use thereof

Info

Publication number
EP3691889A1
EP3691889A1 EP17788137.2A EP17788137A EP3691889A1 EP 3691889 A1 EP3691889 A1 EP 3691889A1 EP 17788137 A EP17788137 A EP 17788137A EP 3691889 A1 EP3691889 A1 EP 3691889A1
Authority
EP
European Patent Office
Prior art keywords
composite material
hot
steel
core layer
hot forming
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.)
Withdrawn
Application number
EP17788137.2A
Other languages
German (de)
French (fr)
Inventor
Janko Banik
Stefan Myslowicki
Matthias Schirmer
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.)
ThyssenKrupp Steel Europe AG
ThyssenKrupp AG
Original Assignee
ThyssenKrupp Steel Europe AG
ThyssenKrupp AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ThyssenKrupp Steel Europe AG, ThyssenKrupp AG filed Critical ThyssenKrupp Steel Europe AG
Publication of EP3691889A1 publication Critical patent/EP3691889A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/01—Layered products comprising a layer of metal all layers being exclusively metallic
    • B32B15/011—Layered products comprising a layer of metal all layers being exclusively metallic all layers being formed of iron alloys or steels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/02—Stamping using rigid devices or tools
    • B21D22/022—Stamping using rigid devices or tools by heating the blank or stamping associated with heat treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/18—Layered products comprising a layer of metal comprising iron or steel
    • 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
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
    • 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
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/13—Modifying the physical properties of iron or steel by deformation by hot working
    • 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
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0478—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing involving a particular surface 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
    • C22C38/001—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
    • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
    • 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
    • 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
    • C22C38/16—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
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/30—Ferrous alloys, e.g. steel alloys containing chromium with cobalt
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/52—Ferrous alloys, e.g. steel alloys containing chromium with nickel with cobalt
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
    • 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
    • B21D22/201—Work-pieces; preparation of the work-pieces, e.g. lubricating, coating
    • 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
    • B21D35/00—Combined processes according to or processes combined with methods covered by groups B21D1/00 - B21D31/00
    • B21D35/002—Processes combined with methods covered by groups B21D1/00 - B21D31/00
    • B21D35/005—Processes combined with methods covered by groups B21D1/00 - B21D31/00 characterized by the material of the blank or the workpiece
    • B21D35/007—Layered blanks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2255/00—Coating on the layer surface
    • B32B2255/06—Coating on the layer surface on metal layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2255/00—Coating on the layer surface
    • B32B2255/20—Inorganic coating
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
    • Y10T428/12611—Oxide-containing component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/1266—O, S, or organic compound in metal component
    • Y10T428/12667—Oxide of transition metal or Al
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12736—Al-base component
    • Y10T428/1275—Next to Group VIII or IB metal-base component
    • Y10T428/12757—Fe
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component
    • Y10T428/12951—Fe-base component
    • Y10T428/12958—Next to Fe-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component
    • Y10T428/12951—Fe-base component
    • Y10T428/12958—Next to Fe-base component
    • Y10T428/12965—Both containing 0.01-1.7% carbon [i.e., steel]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component
    • Y10T428/12951—Fe-base component
    • Y10T428/12972—Containing 0.01-1.7% carbon [i.e., steel]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
    • Y10T428/2495—Thickness [relative or absolute]

Definitions

  • the invention relates to a hot forming composite material from an at least three-layer composite material.
  • Lightweight construction is an essential element in reducing vehicle weight. This can be achieved, inter alia, by the use of materials with increased strength. As the strength increases, its bending capacity tends to decrease. In order to ensure the occupant protection required for crash-relevant components despite increased strength to realize lightweight construction, it must be ensured that the materials used can convert the energy introduced by a crash by deformation. This requires a high degree of formability, especially in the crash-relevant components of a vehicle structure.
  • One way to save weight for example, the body and / or the chassis of a land-based vehicle even easier to design or build by innovative materials compared to the conventionally used materials.
  • component-specific conventional materials can be replaced by materials with thinner wall thicknesses with comparable properties.
  • more and more hybrid materials or composites find their way into the automotive industry, which are composed of two or more different materials, each individual material has certain, partly opposing properties, which are combined in the composite material to composite material in comparison to the individual, monolithic materials to achieve improved properties.
  • Composite materials, in particular of different steels are known in the art, for example from the German patent application DE 10 2008 022 709 AI and from the European patent application EP 2 886 332 AI.
  • a steel composite designed for hot forming is marketed by the Applicant under the trade names "Tribond®” 1200 and 1400.
  • a high strength hardenable steel core layer and a ductile steel top layer in different material thicknesses are used to achieve the high strength target and to achieve ductility in order to achieve an acceptable residual deformability in the press-hardened material pairings
  • a high material thickness of the ductile composite partner is provided. This reduces the strength of the composite material in two ways: firstly, it is the ductile portion itself that leads to it, secondly, the strength of the core is lowered because during production (hot roll plating) and processing (hot working) diffusion flows of the alloying elements between the composite partners occur.
  • the use of thin cover layers achieves a high overall strength, the diffusion processes lead to a comparatively strong hardening of the ductile composite partner, so that the ductility objectives can not be achieved at the end.
  • the abovementioned steel-material composites are cut into blanks and heated to austenitizing temperature, in order to subsequently heat-form and cool them in a cooled mold at the same time (direct hot-forming).
  • the blanks can first be cold formed into a preform, the preform heated and then hot-formed into a finished mold into a finished mold, in particular calibrated and cooled (indirect hot working).
  • intensive cooling cooling rates of at least 27 K / s are required when using a 22MnB5 as a core layer, the structure of austenite completely converts into martensite and the material processed into the component receives its desired high strength in the core layer in the press-hardened state.
  • This process is known in the art also under the term press hardening.
  • the steel material composites used for this purpose are provided with an aluminum-based coating, for example an AlSi coating, in order to avoid unwanted scale formation when the steel plate is heated to austenitizing temperature.
  • steel composite materials with a curable core layer consisting of a steel and cover layers made of stainless steel, in particular chromium steels are known from the state of the art. for example DE 10 2014 116 695 AI and WO 2012/146384 AI. These composite materials exhibit insensitivity to hydrogen induced cracking (delayed fracture), especially when using high strength core layers.
  • chemically resistant steels (chromium steel) as cover layers the goal of corrosion protection for the component produced from the composite material can be achieved, without having to apply additional aluminum-based or zinc-based coatings, in particular before the press-hardening.
  • such a component for example in a vehicle structure, is formed by contact with adjacent components of non-chemically resistant steel, such as carbon steel, a galvanic element, which leads to an increased corrosion attack on the components made of carbon steel.
  • a galvanic element which leads to an increased corrosion attack on the components made of carbon steel.
  • it can be disadvantageous for the made of a composite material with cover layers of chemically resistant stainless steel component, if the stainless steel cover layer would be damaged locally, for example by rockfall. This would also result in the possibility of forming a galvanic element.
  • Chemically resistant steels have a lower expansion behavior in comparison to hardenable steels, depending on their alloying elements and temperature-dependent, so that hot-forming composite materials can be produced reliably only at great expense, for example in hot roll cladding.
  • the invention is based on the object to provide a comparison with the prior art improved and easy to produce hot forming composite material.
  • thermoforming composite of at least one three-layer composite material comprising a core layer of a hardenable steel, in particular having a carbon content C of at least 0.06 wt .-%, in particular at least 0, 12 wt .-%, preferably at least 0, 2 wt .-%, and two cohesively bonded to the core layer cover layers of a ferritic, conversion-free FeAlCr steel, in particular with an aluminum content AI between 2 and 9 wt .-% and a chromium content Cr between 0, 1 and 12 wt .-% , which on the one hand has the aforementioned advantages, in particular can be press-hardened by means of inductive rapid heating, and on the other hand, the disadvantages mentioned above, notably, in particular the problems with respect to corrosion described under use conditions as a component in the press-hardened state in
  • the hot-forming composite material or the composite material is produced by means of plating, in particular roll cladding, preferably hot-rolled cladding or by casting.
  • the hot-formed composite material according to the invention is preferably produced by means of hot-roll cladding, as disclosed, for example, in German Patent DE 10 2005 006 606 B3. Reference is made to this patent, the contents of which are hereby incorporated by reference.
  • the hot-working composite material according to the present invention may be produced by casting, and a possibility for its production is disclosed in Japanese Patent Laid-Open Publication JP-A-03 133 630.
  • Metallic composite fabrication is generally known in the art.
  • the FeAlCr steel cover layers used favor the process temperatures, such as the rolling end temperature and reel temperature, compared to chemically resistant steels (chromium steels), thereby adhering to critical temperature specifications, in particular within a defined process window can be relieved.
  • the FeAlCr steel liners used have one in hot rolling of the preferred hot-roll cladding over a chemically resistant steel (chrome steel) Advantage that is due to the thermal expansion behavior.
  • the (fully) ferritic and thus conversion-free FeAlCr steel has an excellent suitability as a covering layer material, since this ideally averages the fluctuating expansion coefficient of the core layer of hardenable steel in the ferrite-austenite transformation. This results in lower thermal stresses, for example in the welds when connecting the individual layers to packages (slab packages) compared with (fully) ferritic, chemically resistant steels made of chromium steel, by using FeAlCr steel cover layers. This increases the process reliability for producing the hot-forming material.
  • the generally smaller difference in the expansion behavior is up to 700 ° C.
  • the hot-forming material can be designed as a strip, plate or sheet metal or can be made available to the further process steps.
  • the hot forming material can thus be integrated into existing standard processes of hot forming without having to make any changes in the process chain.
  • the ferritic, conversion-free FeAlCr steel of the cover layers is composed of Fe and, in addition to Fe, unavoidable impurities in terms of weight
  • the details of the alloying elements relate in particular to the state (state of delivery) before the production of the composite material.
  • C is at most 0, 1 wt .-%, in particular at most 0.01 wt .-% before. C contributes to increase the strength in the cover layers. The less C, the more ductile the cover layers become, and the higher the bending angle of the hot-forming composite material or of the component in the press-hardened state can be. The minimum content is 0.001 wt .-%.
  • Al is at least 2 wt .-% and at most 9 wt .-%, in particular at most 7% by weight, preferably at most 6 wt .-%, more preferably at most 5.5 wt .-%, in particular the weldability and to promote corrosion protection.
  • AI has an advantageous effect on processing the hot-formed composite material, in particular by press-hardening, since a thin, stable aluminum oxide layer which protects against corrosion forms on the surface.
  • This aluminum oxide layer which consists essentially of Al 2 0 3 and companion elements, such as Si0 2 , Ti0 2 and / or Cr may have 2 0 3 , may also have the further positive effect that blasting of the components after the press-hardening and can be omitted before painting, since it is formed very firmly adhering to the surface of the hot forming composite material.
  • Mn is an austenite former and is therefore limited to a maximum of 1% by weight. With a content of at least 0.01% by weight, in particular of at least 0.02% by weight, Mn can positively influence the adjustment of the strength. Mn may also be included only as an impurity and / or normal companion.
  • Cr is a ferrite former and serves to set diffusing C from the core layer and is present as at least 0.1% by weight, in particular at least 2% by weight, preferably at least 3% by weight, and is not more than 12% by weight. %, in particular not more than 9 wt .-%, preferably at most 7 wt .-% limited. Cr in combination with AI ferrite stabilizes and promotes the freedom of transformation.
  • One compared to chemically resistant Steels of lower chromium content also cause the electrochemical difference to the conventional carbon steels under conditions of use and to the core layer to be lower. The driving force for the course of corrosion processes is thereby substantially reduced.
  • Cr In addition to corrosion resistance, Cr also affects the weldability of a material. This applies in addition to a processing of a press-hardened component of the hot-forming composite material according to the invention and, for example, also preferably its production in the construction of the required packages for hot-roll cladding. Levels above the limits lead to an undesirable passivation, as is known in chemically resistant steels (chromium steels).
  • Mo is limited to a maximum of 2% by weight and may be further restricted in particular to not more than 1% by weight, preferably not more than 0.5% by weight, since Mo is an expensive alloying element. Mo may also be included only as an impurity and / or normal companion.
  • Co is limited to a maximum of 2% by weight and may be further restricted to at most 1% by weight, preferably at most 0.5% by weight, since Co is an expensive alloying element. Co may also be included only as an impurity and / or normal companion.
  • P or S are alloying elements which, individually or in combination, can be counted as contaminants if they are not purposefully alloyed for the purpose of setting specific properties.
  • the contents are limited to a maximum of 0, 1 wt .-% P and a maximum of 0.03 wt .-% S.
  • the alloying elements are each limited to a maximum of 1 wt .-% , and in particular in the range of 0, 1 to 2 wt .-%, preferably 0.25 to 1.5 wt .-% and particularly preferably 0.3 to 1.2 wt .-%, based on the total amount of Ti, Nb, Zr, V and W can lie.
  • the FeAlCr steel it is not necessary for the FeAlCr steel to contain all five of said alloying elements, but it is also possible that the content results only from one, two, three or four of said alloying elements.
  • the elements Ti, Nb, Zr, V and W by virtue of their preferred binding to N over Cr, ensure that the ferrite-forming free Cr content is not reduced by nitride formation.
  • these can Alloy elements C bind, so that the formation of brittle kappa carbides (Fe-Al-carbides) can be avoided.
  • Ti, Nb, Zr, V and / or W may also be included only as an impurity and / or normal companion.
  • the FeAlCr steel is Nb-free.
  • Exemplary representatives of FeAlCr steels with a ferritic, conversion-free structure are known, for example, from the published patent application WO 2013/178629 A1 of the Applicant.
  • the hardenable steel of the core layer consists of Fe and production-related unavoidable impurities in% by weight
  • the details of the alloying elements relate in particular to the state (state of delivery) before the production of the composite material.
  • C is a strength-increasing alloying element and contributes with increasing content to increase the strength, so that a content of at least 0.06 wt .-%, in particular of at least 0.12 wt%, preferably at least 0.2 wt%, more preferably at least 0.28 wt%, more preferably at least 0.33 wt%, even more preferably at least 0.37 Wt .-%, particularly preferably of at least 0.42 wt .-% is present in order to achieve or set the desired strength.
  • the brittleness increases, so that the content to a maximum of 0.8 wt .-%, in particular at most 0.75 wt .-%, preferably at most 0.68 wt .-%, more preferably at most 0.65 wt .-%, more preferably not more than 0.62 wt .-% is limited in order not to adversely affect the material properties and to ensure sufficient weldability.
  • Si is an alloying element that contributes to solid solution hardening and, depending on the content, has a positive effect on an increase in strength, so that a content of at least 0.05% by weight is present.
  • the alloying element is limited to a maximum of 0.5% by weight, in particular a maximum of 0.45% by weight, preferably a maximum of 0.4% by weight, in order to ensure sufficient rolling capability.
  • Mn is an alloying element that contributes to hardenability and increase working time in the hot forming process by conversion delay and has a positive effect on tensile strength, especially for setting S to MnS, so that a content of at least 0.5 wt% is present.
  • the alloying element is limited to a maximum of 3% by weight, in particular a maximum of 2.5% by weight, preferably a maximum of 2.2% by weight, in order to ensure sufficient weldability.
  • Mn is at least 1.5 wt .-%, in particular at least 1.7 wt .-% alloyed to ensure hardenability. If C is at least 0.2% by weight, Mn can be reduced to a maximum of 2% by weight, in particular a maximum of 1.5% by weight.
  • Al may contribute as an alloying element for deoxidation, wherein a content of at least 0.01 wt .-%, in particular 0.015 wt .-% may be present.
  • the alloying element is limited to a maximum of 0.2 wt .-%, in particular at most 0, 15 wt .-%, preferably at most 0, 1 wt .-% to substantially reduce precipitates in the material, in particular in the form of non-metallic oxide inclusions and / or to avoid which can adversely affect the material properties.
  • the content can be adjusted between 0.02 and 0.06 wt .-%.
  • Cr may also contribute to the setting of the strength, in particular to the hardenability, as an alloying element, for example with a content of at least 0.05% by weight.
  • the alloying element is limited to a maximum of 1% by weight, in particular a maximum of 0.8% by weight, preferably a maximum of 0.7% by weight, in order to ensure sufficient weldability.
  • B can contribute to hardenability and increase in strength as an alloying element, in particular when N is set and can be present at a level of at least 0.0008% by weight, in particular of at least 0.001% by weight.
  • the alloying element can be limited to a maximum of 0.01% by weight, in particular to a maximum of 0.008% by weight, since higher contents have an adverse effect on the material properties and would result in a reduction of hardness and / or strength in the material.
  • Ti and Nb may be alloyed as alloying elements singly or in combination for grain refining and / or N-setting, especially when Ti is present at a level of at least 0.005 wt%.
  • the content of Ti should be at least 3.42 * N.
  • the alloying elements in combination are limited to a maximum of 0.2% by weight, in particular not more than 0.15% by weight, preferably not more than 0.1% by weight, since higher contents have a disadvantageous effect on the material properties, in particular adversely on the Toughness of the material.
  • Mo, V, Cu, Ni, Sn, Ca, Co, As, N, P, or S are alloying elements that can be counted as impurities individually or in combination, unless they are specifically added to set specific properties.
  • the contents are limited to a maximum of 0.2% by weight Mo, to a maximum of 0.2% by weight V, to a maximum of 0.2% by weight Cu, to a maximum of 0.4% by weight Ni, to a maximum 0.05% by weight of Sn, to a maximum of 0.01% by weight of Ca, to a maximum of 0.02% by weight of Co, to a maximum of 0.02% by weight of As, to a maximum of 0.01% by weight.
  • the hardenable steel of the core layer of the hot forging composite material has a tensile strength> 500 MPa and / or a hardness> 170 HV10 in the press-hardened state, in particular a tensile strength> 1300 MPa and / or a hardness> 450 HV10, preferably a tensile strength> 1700 MPa and / or a Hardness> 500 HV10, more preferably a tensile strength> 1900 MPa and / or a hardness> 575 HV10, more preferably a tensile strength> 2100 MPa and / or a hardness> 630 HV10.
  • the microstructure in the press-hardened state can be for example at least 90%, preferably at least 95%, more preferably at least 98% martensite and / or a martensite bainite mixed structure exist and may also contain ferrite in the transition region to the core layer. With a tensile strength below 1000 MPa, the proportion of martensite and / or the martensite-bainite mixed structure is correspondingly reduced.
  • Exemplary representatives of hardenable steels are commercially available steels of the group from the DIN standard DIN EN 10883-2, for example the quality C22, C35, C45, C55, C60, manganese-containing steels (DIN EN 10883-3), in particular the grade 20MnB5, 30MnB5 , or 37MnB5, 42CrMo4 according to DIN EN 10263-4 and other grades such as, for. 20MnB8, 22MnB5, 40MnB4, as well as case-hardened steels or air-hardening steels.
  • the cover layers each have a material thickness of ⁇ 22%, in particular ⁇ 17%, preferably ⁇ 12%, particularly preferably ⁇ 9%, based on the total material thickness of the hot-forming composite material.
  • the cover layers have a material thickness of in each case at least 1%, in particular at least 2%, preferably at least 4%, particularly preferably at least 5%, per side, based on the total material thickness of the hot-forming composite material.
  • the hot-forming composite material or the three-layer material composite has a total material thickness between 0.5 and 8.0 mm, in particular between 0.8 and 5.0 mm, and preferably between 1.2 and 4.0 mm.
  • the invention relates to a method for producing a hot-rolled hot-forming composite material from an at least three-layer composite material comprising a core layer of a hardenable steel and two cohesively connected to the core layer cover layers (1.2) of a ferritic, conversion-free FeAlCr steel, the method comprising the following Steps:
  • thermoforming composite material can be carried out in analogy to the teaching according to DE 10 2005 006 606 B3.
  • the surfaces of the layers can each be subjected to a cleaning operation for removing foreign substances on the surface and / or a machining, in particular for setting a predefined flatness.
  • the layers are assembled, for example in the form of sheets, plates, slabs or slabs.
  • the layer of hardenable steel and the layers of FeAlCr steel preferably have the chemical alloying elements as previously defined above. All of the aforementioned advantages also apply in connection with the process according to the invention for producing a hot-formed composite material.
  • the invention relates to a component produced from a hot-formed composite material according to the invention by means of press-hardening or multi-stage hot-forming method, in particular for producing a component for the automotive, railway, shipbuilding or aerospace industry.
  • Press hardening can be done by direct or indirect hot working.
  • a multi-stage hot forming process is to be understood to mean hot forming in at least two tools and / or in at least two operating stages with optional trimming and subsequent press hardening.
  • EP 3 067 128 A1 By way of example, reference is made to EP 3 067 128 A1.
  • the component has an aluminum oxide layer, in particular with a thickness of up to 1000 nm, in particular up to 300 nm, preferably up to 200 nm, more preferably up to 150 nm.
  • the invention relates to a use of a component produced from the hot-formed composite material according to the invention in a body or in the chassis of a land-bound vehicle.
  • a land-bound vehicle preferably passenger cars, commercial vehicles or buses, be it with an internal combustion engine, purely electrically powered or hybrid-powered vehicles.
  • the components can be used as longitudinal, transverse beams or columns in land-bound vehicle, for example, they are designed as profiles, in particular as a crash profile in the bumper, sill, side impact or in areas where no to small deformations / intrusions in the event of a crash are required or can be designed in the chassis as a wishbone, stabilizers or torsion beam rear axle.
  • Fig. 1 shows a schematic section through an inventive thermoforming composite material.
  • the single FIGURE shows a schematic sectional view through a hot-formed composite material (1) according to the invention.
  • the hot-formed composite material (1) according to the invention comprises a core layer (1.1) made of a hardenable steel having a carbon content C of at least 0.06 wt .-%, which in the press-hardened state, a tensile strength> 500 MPa and / or a hardness> 170 HV10, in particular a Tensile strength> 1300 MPa and / or a hardness> 450 HV10, preferably a tensile strength> 1700 MPa and / or a hardness> 520 HV10, more preferably a tensile strength> 1900 MPa and / or a hardness> 575 HV10, two cohesively with the core layer (1.1) joined cover layers (1.2) of a ferrite, conversion-free FeAlCr steel having an aluminum content AI between 3 and 7 wt .-% and a chromium content Cr between 0, 1
  • the material thickness of the cover layers (1.3) is at least 1% per side and a maximum of 22%, preferably at least 4% and a maximum of 12% based on the total material thickness of the hot forging composite material (1), wherein the thermoforming composite material (1), for example, may have a total material thickness between 0.5 and 8 mm.
  • a hot forming composite material was produced by means of hot rolling, which had a three-layer composite material.
  • the cover layers used were steel Fe-5,4AI-6Cr-0,04Ti and the core layer used was a hardenable steel of the designation 37MnB5.
  • each sheet metal blanks (slabs) were stacked to form a core layer with two cover layers, which were at least partially joined together along their edges cohesively, preferably by welding to a pre-bond. Due to the lower Cr content compared to chemically resistant steels (chromium steels), package construction was less complicated.
  • the precoat was brought to a temperature of> 1200 ° C in an oven and hot rolled in several steps to a composite material with a total material thickness of 3 mm and then further processed to form a cold strip of 1.5 mm.
  • Blanks were separated from the hot-formed composite material produced.
  • the blanks were heated to Austenitmaschinestemperatur, in particular above A c3 (based on the core layer) by induction or heated and then hot formed into a cooled tool to components and cooled.
  • the cooling rates were> 30 K / s.
  • the core layer was essentially entirely of martensite over the thickness and at the transition to the top layer, the microstructure contained additional amounts of bainite and / or ferrite.
  • the cover layer essentially retained its initial structure, which it had at the time of preparation prior to production of the material composite and further processing into a component, so that no conversion took place.
  • the cover layers made of FeAlCr steel have a positive influence on the bending properties of the composite material or hotforming composite material, because in addition to its own low strength and thus high ductility, it offers the possibility of influencing the diffusion processes that occur in the core situation of the composite material high strength, local areas of lesser strength arise.
  • the material thickness of the cover layers per side was 6% based on the total material thickness of the hot forging composite material, so that the core layer had a material thickness of 88% based on the total material thickness.
  • the thickness of the aluminum oxide layer formed on the surface of the aluminum oxide layer formed during the press-hardening was less than 150 nm.
  • the hot-formed composite material according to the invention can also be part of a tailored product, for example part of a tailored welded blank and / or tailored rolled blank, and also have more than three layers.
  • a component can also be produced by means of a multi-stage hot forming process.

Landscapes

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

Abstract

The invention relates to a hot-forming composite material (1) formed from an at least three-ply material composite comprising a core ply (1.1) made of a hardenable steel and two outer plies (1.2) connected in an integrally bonded manner to the core ply (1.1) and made of a ferritic, transformation-free FeAlCr steel.

Description

WARMUMFORMVERBUNDMATERIAL, DESSEN HERSTELLUNG,  HOTMOLD COMPOSITE MATERIAL, THE PRODUCTION THEREOF,
BAUTEIL UND DESSEN VERWENDUNG  COMPONENT AND ITS USE
Technisches Gebiet (Technical Field) Technical Field
Die Erfindung betrifft ein Warmumformverbundmaterial aus einem zumindest dreilagigen Werkstoffverbund.  The invention relates to a hot forming composite material from an at least three-layer composite material.
Technischer Hintergrund (Background Art) Technical Background (Background Art)
In der Automobilindustrie wird nach neuen Lösungen zur Reduzierung des Fahrzeuggewichts und damit einhergehend zur Reduzierung des Kraftstoffverbrauchs gesucht. Leichtbau ist dabei ein wesentlicher Baustein, um das Fahrzeuggewicht senken zu können. Dies kann unter anderem durch den Einsatz von Werkstoffen mit gesteigerter Festigkeit erzielt werden. Mit dem Anstieg der Festigkeit nimmt in der Regel dessen Biegevermögen ab. Um trotz gesteigerter Festigkeit zur Realisierung von Leichtbau auch den bei crashrelevanten Bauteilen erforderlichen Insassenschutz sicherzustellen, ist zu gewährleisten, dass die eingesetzten Werkstoffe die durch einen Crash eingeleitete Energie durch Deformation umwandeln können. Dies bedingt ein hohes Maß an Umformvermögen insbesondere in den crashrelevanten Bauteilen einer Fahrzeugstruktur. Eine Möglichkeit, Gewicht einzusparen, ist beispielsweise die Karosserie und/oder das Fahrwerk eines landgebundenen Fahrzeugs noch leichter, durch innovative Werkstoffe im Vergleich zu den konventionell eingesetzten Werkstoffen zu gestalten bzw. zu bauen. So können beispielsweise bauteilspezifisch konventionelle Werkstoffe durch Werkstoffe mit dünneren Wandstärken mit vergleichbaren Eigenschaften ersetzt werden. Beispielsweise finden immer mehr Hybridwerkstoffe oder Werkstoffverbunde Einzug in der Automobilindustrie, die aus zwei oder mehreren unterschiedlichen Materialien zusammengesetzt sind, wobei jedes einzelne Material bestimmte, teils gegensätzliche Eigenschaften aufweist, die im Werkstoffverbund vereint werden, um im Werkstoffverbund im Vergleich zu den einzelnen, monolithischen Materialien verbesserte Eigenschaften zu erzielen. Werkstoffverbunde, insbesondere aus unterschiedlichen Stähle sind im Stand der Technik bekannt, beispielsweise aus der deutschen Offenlegungsschrift DE 10 2008 022 709 AI und aus der europäischen Offenlegungsschrift EP 2 886 332 AI .  The automotive industry is looking for new solutions to reduce vehicle weight and thus reduce fuel consumption. Lightweight construction is an essential element in reducing vehicle weight. This can be achieved, inter alia, by the use of materials with increased strength. As the strength increases, its bending capacity tends to decrease. In order to ensure the occupant protection required for crash-relevant components despite increased strength to realize lightweight construction, it must be ensured that the materials used can convert the energy introduced by a crash by deformation. This requires a high degree of formability, especially in the crash-relevant components of a vehicle structure. One way to save weight, for example, the body and / or the chassis of a land-based vehicle even easier to design or build by innovative materials compared to the conventionally used materials. For example, component-specific conventional materials can be replaced by materials with thinner wall thicknesses with comparable properties. For example, more and more hybrid materials or composites find their way into the automotive industry, which are composed of two or more different materials, each individual material has certain, partly opposing properties, which are combined in the composite material to composite material in comparison to the individual, monolithic materials to achieve improved properties. Composite materials, in particular of different steels are known in the art, for example from the German patent application DE 10 2008 022 709 AI and from the European patent application EP 2 886 332 AI.
Ein für die Warmumformung konzipierter Stahl-Werkstoffverbund wird seitens der Anmelderin unter dem Handelsnamen„Tribond®" 1200 und 1400 vertrieben. Es wird ein höchstfester, härtbarer Stahl als Kernlage und ein duktiler Stahl als Decklagen in unterschiedlichen Materialdicken eingesetzt, um das Ziel aus hoher Festigkeit und Duktilität zu erreichen. Um bei solchen Werkstoffpaarungen ein akzeptables Restumformvermögen im pressgehärteten Zustand zu erreichen, ist eine hohe Materialdicke des duktilen Verbundpartners vorgesehen. Dies reduziert die Festigkeit des Werkstoffverbundes auf zwei Arten: erstens ist es der duktile Anteil selbst, der hierzu führt, zweitens wird die Festigkeit des Kerns gesenkt, da im Verlauf der Fertigung (Warmwalzplattieren) und der Verarbeitung (Warmumformung) Diffusionsströme der Legierungselemente zwischen den Verbundpartnern auftreten. Beispielsweise diffundiert Kohlenstoff von der Kernlage in die Decklage, härtet diese auf und senkt dabei gleichzeitig die Festigkeit im Kernbereich. Bei Verwendung von dünnen Decklagen wird zwar eine hohe Gesamtfestigkeit erreicht, durch die Diffusionsprozesse tritt aber eine vergleichsweise starkes Aufhärten des duktilen Verbundpartners auf, so dass die Duktilitätsziele am Ende nicht erreicht werden können. A steel composite designed for hot forming is marketed by the Applicant under the trade names "Tribond®" 1200 and 1400. A high strength hardenable steel core layer and a ductile steel top layer in different material thicknesses are used to achieve the high strength target and to achieve ductility in order to achieve an acceptable residual deformability in the press-hardened material pairings To achieve state, a high material thickness of the ductile composite partner is provided. This reduces the strength of the composite material in two ways: firstly, it is the ductile portion itself that leads to it, secondly, the strength of the core is lowered because during production (hot roll plating) and processing (hot working) diffusion flows of the alloying elements between the composite partners occur. For example, carbon diffuses from the core layer into the cover layer, hardens it and simultaneously reduces the strength in the core region. Although the use of thin cover layers achieves a high overall strength, the diffusion processes lead to a comparatively strong hardening of the ductile composite partner, so that the ductility objectives can not be achieved at the end.
Bei der Warmumformung werden die eingangs erwähnten Stahlwerkstoffverbunde zu Platinen zugeschnitten und auf Austenitisierungstemperatur erwärmt, um sie anschließend in einem gekühlten Werkzeug gleichzeitig warm umzuformen und abzukühlen (direkte Warmumformung). Alternativ können die Platinen zunächst kalt zu einer Vorform umgeformt werden, die Vorform erwärmt und anschließend in einem gekühlten Werkzeug zu einer Fertigform warm geformt, insbesondere kalibriert und abgekühlt wird (indirekte Warmumformung). Durch eine intensive Abkühlung, wobei Abkühlraten von mindestens 27 K/s beim Einsatz eines 22MnB5 als Kernlage erforderlich sind, wandelt das Gefüge von Austenit vollständig in Martensit um und der zum Bauteil verarbeitete Werkstoff erhält im pressgehärteten Zustand seine angestrebte hohe Festigkeit in der Kernlage. Dieses Verfahren ist in den Fachkreisen auch unter dem Begriff Presshärten bekannt. Die hierzu eingesetzten Stahlwerkstoffverbunde sind mit einem aluminiumbasierten Überzug, beispielsweise einem AlSi-Überzug versehen, um beim Erwärmen der Stahlplatine auf Austenitisierungstemperatur eine unerwünschte Zunderbildung zu vermeiden. In hot forming, the abovementioned steel-material composites are cut into blanks and heated to austenitizing temperature, in order to subsequently heat-form and cool them in a cooled mold at the same time (direct hot-forming). Alternatively, the blanks can first be cold formed into a preform, the preform heated and then hot-formed into a finished mold into a finished mold, in particular calibrated and cooled (indirect hot working). By intensive cooling, cooling rates of at least 27 K / s are required when using a 22MnB5 as a core layer, the structure of austenite completely converts into martensite and the material processed into the component receives its desired high strength in the core layer in the press-hardened state. This process is known in the art also under the term press hardening. The steel material composites used for this purpose are provided with an aluminum-based coating, for example an AlSi coating, in order to avoid unwanted scale formation when the steel plate is heated to austenitizing temperature.
Des Weiteren sind aus dem Stand der Technik Stahl-Werkstoffverbunde mit einer aus einer Stahl bestehenden härtbaren Kernlage und Decklagen aus Edelstähle, insbesondere Chromstähle bekannt, s. beispielsweise DE 10 2014 116 695 AI und WO 2012/146384 AI. Diese Werkstoffverbunde weisen eine Unempfindlichkeit gegenüber einer Wasserstoff induzierten Rissbildung (delayed fracture) auf, insbesondere bei der Verwendung von Kernlagen mit hohen Festigkeiten. Durch den Einsatz von chemisch beständigen Stählen (Chromstahl) als Decklagen kann das Ziel eines Korrosionsschutzes für das aus dem Werkstoffverbund hergestellte Bauteil erreicht werden, ohne insbesondere vor dem Presshärten zusätzliche aluminiumbasierte oder zinkbasierte Beschichtungen aufbringen zu müssen. Bei der Integration eines solchen Bauteils, beispielsweise in einer Fahrzeugstruktur, wird durch den Kontakt mit angrenzenden Bauteilen aus nicht chemisch beständigem Stahl, beispielsweise Kohlenstoffstahl, ein galvanisches Element gebildet, das zu einem verstärkten Korrosionsangriff an den Bauteilen aus Kohlenstoffstahl führt. Im Fall eines solchen Bauteilkombination in einer Fahrzeugstruktur wären daher aufwendige, zusätzliche Korrosionsschutzmaßnahmen zu ergreifen, die das Ausbilden eines galvanischen Elementes verhindern oder die aus Kohlenstoffstahl bestehenden Bauteile anderweitig schützen. Des Weiteren kann sich für das aus einem Werkstoffverbund mit Decklagen aus chemisch beständigen Edelstähle gefertigte Bauteil daraus nachteilig ergeben, wenn die Edelstahldecklage beispielsweise durch Steinschlag lokal beschädigt werden würde. Auch hieraus würde sich die Möglichkeit zur Bildung eines galvanischen Elementes ergeben. Die Gefährdung des aus dem Werkstoffverbund gebildeten Bauteils durch einen korrosiven Angriff wäre aber aufgrund der Größe von Anode (kleiner geschädigter Bereich) zur Kathode (großer intakter Oberflächenbereich) deutlich größer gegenüber dem oben beschriebenen Fall der Bauteilkombination. Neben einer hohen Festigkeit größer 1400 MPa, gemittelt über die Gesamtmaterialdicke des Werkstoffverbundes respektive eines Bauteils im pressgehärteten Zustand, einer ausreichenden Restduktilität, welche über den im 3 Punkt-Biegeversuch erreichten Biegewinkel beschrieben wird (VDA 238- 100), einer Möglichkeit zur induktiven Schnellerwärmung, einer Unempfindlichkeit gegenüber wasserstoffinduzierter Rissbildung sowie einem ausreichenden Korrosionsschutz sollte der Werkstoffverbund respektive das Bauteil im pressgehärteten Zustand auch eine gute Lackierfähigkeit der Oberfläche besitzen. Furthermore, steel composite materials with a curable core layer consisting of a steel and cover layers made of stainless steel, in particular chromium steels, are known from the state of the art. for example DE 10 2014 116 695 AI and WO 2012/146384 AI. These composite materials exhibit insensitivity to hydrogen induced cracking (delayed fracture), especially when using high strength core layers. Through the use of chemically resistant steels (chromium steel) as cover layers, the goal of corrosion protection for the component produced from the composite material can be achieved, without having to apply additional aluminum-based or zinc-based coatings, in particular before the press-hardening. In the integration such a component, for example in a vehicle structure, is formed by contact with adjacent components of non-chemically resistant steel, such as carbon steel, a galvanic element, which leads to an increased corrosion attack on the components made of carbon steel. In the case of such a combination of components in a vehicle structure, therefore, would require complex, additional corrosion protection measures that prevent the formation of a galvanic element or otherwise protect the components made of carbon steel. Furthermore, it can be disadvantageous for the made of a composite material with cover layers of chemically resistant stainless steel component, if the stainless steel cover layer would be damaged locally, for example by rockfall. This would also result in the possibility of forming a galvanic element. Due to the size of the anode (small damaged area) to the cathode (large intact surface area), however, the danger of the component formed from the material composite by a corrosive attack would be significantly greater than the case of the component combination described above. In addition to a high strength greater than 1400 MPa, averaged over the total material thickness of the composite material or a component in the press-hardened state, a sufficient Restduktilität which is described in the 3 point bending test reached bending angle (VDA 238-100), a possibility for inductive rapid heating, Insensitivity to hydrogen-induced cracking and adequate corrosion protection of the composite material respectively the component in the press-hardened state should also have a good paintability of the surface.
Chemisch beständige Stähle (Chromstähle) besitzen im Vergleich zu härtbaren Stählen in Abhängigkeit von ihren Legierungselementen und temperaturabhängig ein geringeres Ausdehnungsverhalten, so dass Warmumformverbundmaterialien nur unter hohem Aufwand beispielsweise beim Warmwalzplattieren prozesssicher hergestellt werden können. Chemically resistant steels (chromium steels) have a lower expansion behavior in comparison to hardenable steels, depending on their alloying elements and temperature-dependent, so that hot-forming composite materials can be produced reliably only at great expense, for example in hot roll cladding.
Zusammenfassung der Erfindung (Summary of Invention) Summary of Invention
Der Erfindung liegt die Aufgabe zu Grunde, ein im Vergleich zum Stand der Technik verbessertes und einfach herzustellendes Warmumformverbundmaterial bereitzustellen.  The invention is based on the object to provide a comparison with the prior art improved and easy to produce hot forming composite material.
Gelöst wird diese Aufgabe durch ein Warmumformverbundmaterial mit den Merkmalen des Patentanspruchs l. Weitere vorteilhafte Ausführungsformen der Erfindung sind in den nachgelagerten Ansprüchen aufgeführt. Die Erfinder haben festgestellt, dass ein Warmumformverbundmaterial aus zumindest einem dreilagigen Werkstoffverbund umfassend eine Kernlage aus einem härtbaren Stahl, insbesondere mit einem Kohlenstoffanteil C von mindestens 0,06 Gew.-%, insbesondere mindestens 0, 12 Gew.-%, vorzugsweise mindestens 0,2 Gew.-%, und zwei stoffschlüssig mit der Kernlage verbundenen Decklagen aus einem ferritisch, umwandlungsfreien FeAlCr-Stahl, insbesondere mit einem Aluminiumgehalt AI zwischen 2 und 9 Gew.-% und einem Chromgehalt Cr zwischen 0, 1 und 12 Gew.-%, bereitgestellt wird, welcher zum einen die vorgenannten Vorteile aufweist, insbesondere mittels induktiver Schnellerwärmung pressgehärtet werden kann, und zum anderen die vorgenannten Nachteile im Wesentlichen kompensiert, insbesondere die unter Einsatzbedingungen als Bauteil im pressgehärteten Zustand in einer Fahrzeugstruktur beschriebenen Probleme hinsichtlich der Korrosion nicht oder nur abgemildert aufweist. Durch einen FeAlCr-Stahl als Decklagen mit einer ferritischen, umwandlungsfreien Gitterstruktur sind die Legierungselemente insbesondere in elektrochemischer Hinsicht im Wesentlichen nicht oder nur geringfügig verschieden von den konventionell eingesetzten Kohlenstoffstählen in einer Fahrzeugstruktur. This object is achieved by a hot forming composite material with the features of claim l. Further advantageous embodiments of the invention are listed in the following claims. The inventors have found that a thermoforming composite of at least one three-layer composite material comprising a core layer of a hardenable steel, in particular having a carbon content C of at least 0.06 wt .-%, in particular at least 0, 12 wt .-%, preferably at least 0, 2 wt .-%, and two cohesively bonded to the core layer cover layers of a ferritic, conversion-free FeAlCr steel, in particular with an aluminum content AI between 2 and 9 wt .-% and a chromium content Cr between 0, 1 and 12 wt .-% , which on the one hand has the aforementioned advantages, in particular can be press-hardened by means of inductive rapid heating, and on the other hand, the disadvantages mentioned above, notably, in particular the problems with respect to corrosion described under use conditions as a component in the press-hardened state in a vehicle structure only or not has mitigated. By means of a FeAlCr steel as cover layers with a ferritic, non-transforming lattice structure, the alloying elements are essentially not or only slightly different from the conventionally used carbon steels in a vehicle structure, especially in electrochemical terms.
Das Warmumformverbundmaterial respektive der Werkstoffverbund ist mittels Plattieren, insbesondere Walzplattieren, vorzugsweise Warmwalzplattieren oder mittels Gießen hergestellt. Bevorzugt ist das erfindungsgemäße Warmumformverbundmaterial mittels Warmwalzplattieren, wie es beispielsweise in der deutschen Patentschrift DE 10 2005 006 606 B3 offenbart ist, hergestellt. Es wird Bezug auf diese Patentschrift genommen, deren Inhalt hiermit in diese Anmeldung aufgenommen wird. Alternativ kann das erfindungsgemäße Warmumformverbundmaterial mittels Gießen hergestellt werden, wobei eine Möglichkeit zu seiner Herstellung in der japanischen Offenlegungsschrift JP-A 03 133 630 offenbart ist. Die metallische Werkstoffverbundherstellung ist allgemein aus dem Stand der Technik bekannt. The hot-forming composite material or the composite material is produced by means of plating, in particular roll cladding, preferably hot-rolled cladding or by casting. The hot-formed composite material according to the invention is preferably produced by means of hot-roll cladding, as disclosed, for example, in German Patent DE 10 2005 006 606 B3. Reference is made to this patent, the contents of which are hereby incorporated by reference. Alternatively, the hot-working composite material according to the present invention may be produced by casting, and a possibility for its production is disclosed in Japanese Patent Laid-Open Publication JP-A-03 133 630. Metallic composite fabrication is generally known in the art.
Insbesondere in Hinblick auf die Herstellung des Warmumformverbundmaterials mittels bevorzugtem Warmwalzplattieren begünstigen die eingesetzten Decklagen aus FeAlCr-Stahl die Prozesstemperaturen, wie beispielsweise die Walzendtemperatur und Haspeltemperatur, im Vergleich zu chemisch beständigen Stählen (Chromstählen), wodurch das Einhalten kritischer Temperaturvorgaben, insbesondere innerhalb eines definierten Prozessfensters erleichtert werden kann. Particularly with regard to the production of the hot-forming composite material by means of preferred hot-roll cladding, the FeAlCr steel cover layers used favor the process temperatures, such as the rolling end temperature and reel temperature, compared to chemically resistant steels (chromium steels), thereby adhering to critical temperature specifications, in particular within a defined process window can be relieved.
Die eingesetzten Decklagen aus FeAlCr-Stahl haben beim Warmwalzen des bevorzugten Warmwalzplattierens gegenüber einem chemisch beständigen Stahl (Chromstahl) einen Vorteil, der im thermischen Ausdehnungsverhalten begründet liegt. Einerseits zeigt der (voll-) ferritische und damit umwandlungsfreie FeAlCr-Stahl eine ausgezeichnete Eignung als Decklagenwerkstoff, da dieser den schwankenden Ausdehnungskoeffizient der Kernlage aus härtbarem Stahl bei der Ferrit-Austenit-Umwandlung in idealer Weise mittelt. Damit entstehen durch den Einsatz von Decklagen aus FeAlCr-Stahl geringere Wärmespannungen, beispielsweise in den Schweißnähten beim Verbinden der einzelnen Lagen zu Paketen (Brammenpaketen) als im Vergleich mit (voll-) ferritischen, chemisch beständigen Stählen aus Chromstahl. Hierdurch wird die Prozesssicherheit zur Herstellung des Warmumformmaterials erhöht. Andererseits, in gleicher Weise wirkender Effekt, ist der allgemein geringere Unterschied im Ausdehnungsverhalten bis zu 700°C. The FeAlCr steel liners used have one in hot rolling of the preferred hot-roll cladding over a chemically resistant steel (chrome steel) Advantage that is due to the thermal expansion behavior. On the one hand, the (fully) ferritic and thus conversion-free FeAlCr steel has an excellent suitability as a covering layer material, since this ideally averages the fluctuating expansion coefficient of the core layer of hardenable steel in the ferrite-austenite transformation. This results in lower thermal stresses, for example in the welds when connecting the individual layers to packages (slab packages) compared with (fully) ferritic, chemically resistant steels made of chromium steel, by using FeAlCr steel cover layers. This increases the process reliability for producing the hot-forming material. On the other hand, in the same way acting effect, the generally smaller difference in the expansion behavior is up to 700 ° C.
Das Warmumformmaterial kann band-, platten- oder blechförmig ausgeführt sein bzw. den weiteren Prozessschritten bereitgestellt werden. Das Warmumformmaterial kann somit in bestehende Standard-Prozesse der Warmumformung integriert werden, ohne Änderungen in der Prozesskette vornehmen zu müssen. The hot-forming material can be designed as a strip, plate or sheet metal or can be made available to the further process steps. The hot forming material can thus be integrated into existing standard processes of hot forming without having to make any changes in the process chain.
Gemäß einer ersten bevorzugten Ausgestaltung des Warmumformverbundmaterials besteht der ferritische, umwandlungsfreie FeAlCr-Stahl der Decklagen neben Fe und herstellungsbedingt unvermeidbaren Verunreinigungen in Gew.-% aus According to a first preferred embodiment of the hot-forming composite material, the ferritic, conversion-free FeAlCr steel of the cover layers is composed of Fe and, in addition to Fe, unavoidable impurities in terms of weight
C: bis 0, 15 %, C: to 0, 15%,
AI: 2 bis 9 %,  AI: 2 to 9%,
Cr: 0, 1 bis 12 %,  Cr: 0, 1 to 12%,
Si: bis 2 %,  Si: up to 2%,
Mn: bis 1 %,  Mn: up to 1%,
Mo: bis 2 %,  Mo: up to 2%,
Co: bis 2 %  Co: up to 2%
P: bis 0, 1 %,  P: to 0, 1%,
S: bis 0,03 %,  S: up to 0.03%,
Ti: bis 1 %,  Ti: up to 1%,
Nb: bis 1 %,  Nb: up to 1%,
Zr: bis 1 %,  Zr: up to 1%,
V: bis 1 %,  V: up to 1%,
W: bis 1 %. Die Angaben der Legierungselemente beziehen sich insbesondere auf den Zustand (Anlieferungszustand) vor der Erzeugung des Werkstoffverbundes. W: up to 1%. The details of the alloying elements relate in particular to the state (state of delivery) before the production of the composite material.
C liegt mit maximal 0, 1 Gew.-%, insbesondere maximal 0,01 Gew.-% vor. C trägt zur Steigerung der Festigkeit in den Decklagen bei. Je weniger C, umso duktiler werden die Decklagen und umso höher kann der Biegewinkel des Warmumformverbundmaterials respektive des Bauteils im pressgehärteten Zustand ausfallen. Der Mindestgehalt liegt bei 0,001 Gew.-%. C is at most 0, 1 wt .-%, in particular at most 0.01 wt .-% before. C contributes to increase the strength in the cover layers. The less C, the more ductile the cover layers become, and the higher the bending angle of the hot-forming composite material or of the component in the press-hardened state can be. The minimum content is 0.001 wt .-%.
AI liegt mit mindestens 2 Gew.-% und mit maximal 9 Gew.-%, insbesondere maximal 7 Gew.- %, bevorzugt maximal 6 Gew.-%, besonders bevorzugt maximal 5,5 Gew.-% vor, um insbesondere die Schweißbarkeit und den Korrosionsschutz zu begünstigen. Der Mindestgehalt von 2 Gew.-%, insbesondere von mindestens 3 Gew.-%, bevorzugt von mindestens 4 Gew.-% führt in Kombination mit Cr zu einer stabilen, ferritischen Gitterstruktur in den Decklagen. Unterhalb von 2 Gew.-% ist die Umwandlungsfreiheit, insbesondere bei der Erwärmung im Zuge des Warmwalzens des Warmumformverbundmaterials und auch im Zuge des Presshärtens nicht mehr gewährleistet. Des Weiteren wirkt sich AI bei der Verarbeitung des Warmumformverbundmaterials insbesondere durch Presshärten vorteilhaft aus, da sich an der Oberfläche eine dünne, stabile und vor Korrosion schützende Aluminiumoxidschicht ausbildet. Diese Aluminiumoxidschicht, die im Wesentlichen aus Al203 besteht und Begleitelemente, wie zum Beispiel Si02, Ti02 und/oder Cr203 aufweisen kann, kann auch den weiteren positiven Effekt haben, dass ein Strahlen der Bauteile nach dem Presshärten und vor einem Lackieren entfallen kann, da sie sehr fest anhaftend auf der Oberfläche des Warmumformverbundmaterials ausgebildet ist. Al is at least 2 wt .-% and at most 9 wt .-%, in particular at most 7% by weight, preferably at most 6 wt .-%, more preferably at most 5.5 wt .-%, in particular the weldability and to promote corrosion protection. The minimum content of 2% by weight, in particular of at least 3% by weight, preferably of at least 4% by weight, leads in combination with Cr to a stable, ferritic lattice structure in the cover layers. Below 2 wt .-%, the freedom of conversion, especially when heating in the course of hot rolling of hot forging composite material and also in the course of press hardening is no longer guaranteed. Furthermore, AI has an advantageous effect on processing the hot-formed composite material, in particular by press-hardening, since a thin, stable aluminum oxide layer which protects against corrosion forms on the surface. This aluminum oxide layer, which consists essentially of Al 2 0 3 and companion elements, such as Si0 2 , Ti0 2 and / or Cr may have 2 0 3 , may also have the further positive effect that blasting of the components after the press-hardening and can be omitted before painting, since it is formed very firmly adhering to the surface of the hot forming composite material.
Mn ist ein Austenitbildner und ist daher auf maximal 1 Gew.-% beschränkt. Mn kann mit einem Gehalt von mindestens 0,01 Gew.-%, insbesondere von mindestens 0,02 Gew.-% positiv Einfluss nehmen auf die Einstellung der Festigkeit nehmen. Mn kann auch nur als Verunreinigung und/oder normaler Begleiter enthalten sein. Mn is an austenite former and is therefore limited to a maximum of 1% by weight. With a content of at least 0.01% by weight, in particular of at least 0.02% by weight, Mn can positively influence the adjustment of the strength. Mn may also be included only as an impurity and / or normal companion.
Cr ist ein Ferritbildner und dient zur Abbindung von eindiffundierendem C aus der Kernlage und liegt mit mindestens 0, 1 Gew.-%, insbesondere mindestens 2 Gew.-%, vorzugsweise mindestens 3 Gew.-% vor und ist auf maximal 12 Gew.-%, insbesondere maximal 9 Gew.-%, vorzugsweise maximal 7 Gew.-% beschränkt. Cr wirkt in Kombination mit AI Ferrit stabilisierend und begünstigt die Umwandlungsfreiheit. Ein im Vergleich zu chemisch beständigen Stählen geringerer Chromgehalt führt auch dazu, dass der elektrochemische Unterschied zu den konventionellen Kohlenstoffstählen unter Einsatzbedingungen und zur Kernlage geringer ist. Die Triebkraft für das Ablaufen von Korrosionsprozessen wird dadurch im Wesentlichen verringert. Cr is a ferrite former and serves to set diffusing C from the core layer and is present as at least 0.1% by weight, in particular at least 2% by weight, preferably at least 3% by weight, and is not more than 12% by weight. %, in particular not more than 9 wt .-%, preferably at most 7 wt .-% limited. Cr in combination with AI ferrite stabilizes and promotes the freedom of transformation. One compared to chemically resistant Steels of lower chromium content also cause the electrochemical difference to the conventional carbon steels under conditions of use and to the core layer to be lower. The driving force for the course of corrosion processes is thereby substantially reduced.
Neben der Korrosionsbeständigkeit beeinflusst Cr auch die Schweißbarkeit eines Werkstoffes. Dies betrifft neben einer Verarbeitung eines pressgehärteten Bauteils aus dem erfindungsgemäßen Warmumformverbundmaterial und beispielsweise auch dessen vorzugsweise Herstellung beim Aufbau der benötigten Pakete zum Warmwalzplattieren. Gehalte oberhalb der Grenzen führen zu einer unerwünschten Passivierung, wie sie bei chemisch beständigen Stählen (Chromstählen) bekannt ist. In addition to corrosion resistance, Cr also affects the weldability of a material. This applies in addition to a processing of a press-hardened component of the hot-forming composite material according to the invention and, for example, also preferably its production in the construction of the required packages for hot-roll cladding. Levels above the limits lead to an undesirable passivation, as is known in chemically resistant steels (chromium steels).
Mo ist auf maximal 2 Gew.-% und kann auch weiter insbesondere auf maximal 1 Gew.-%, vorzugsweise maximal 0,5 Gew.-% beschränkt werden, da Mo ein teures Legierungselement ist. Mo kann auch nur als Verunreinigung und/oder normaler Begleiter enthalten sein. Mo is limited to a maximum of 2% by weight and may be further restricted in particular to not more than 1% by weight, preferably not more than 0.5% by weight, since Mo is an expensive alloying element. Mo may also be included only as an impurity and / or normal companion.
Co ist auf maximal 2 Gew.-% und kann auch weiter insbesondere auf maximal 1 Gew.-%, vorzugsweise maximal 0,5 Gew.-% beschränkt werden, da Co ein teures Legierungselement ist. Co kann auch nur als Verunreinigung und/oder normaler Begleiter enthalten sein. Co is limited to a maximum of 2% by weight and may be further restricted to at most 1% by weight, preferably at most 0.5% by weight, since Co is an expensive alloying element. Co may also be included only as an impurity and / or normal companion.
P oder S sind Legierungselemente, die einzeln oder in Kombination, wenn sie nicht gezielt zur Einstellung spezieller Eigenschaften zulegiert werden, zu den Verunreinigungen gezählt werden können. Die Gehalte sind beschränkt auf maximal 0, 1 Gew.-% P und auf maximal 0,03 Gew.-% S. P or S are alloying elements which, individually or in combination, can be counted as contaminants if they are not purposefully alloyed for the purpose of setting specific properties. The contents are limited to a maximum of 0, 1 wt .-% P and a maximum of 0.03 wt .-% S.
Darüber hinaus kann es von Vorteil sein, wenn ein Anteil an Ti, Nb, Zr, V und/oder W vorhanden ist, der in Summe größer ist als die herstellungsbedingt unvermeidbaren Verunreinigungen, wobei die Legierungselemente jeweils auf maximal 1 Gew.-% beschränkt sind, und insbesondere im Bereich von 0, 1 bis 2 Gew.-%, bevorzugt 0,25 bis 1,5 Gew.-% und besonders bevorzugt 0,3 bis 1,2 Gew.-%, bezogen auf die Gesamtmenge an Ti, Nb, Zr, V und W, liegen können. In diesem Fall ist es nicht erforderlich, dass der FeAlCr-Stahl alle fünf der genannten Legierungselemente enthält, sondern es ist auch möglich, dass sich der Gehalt nur durch eines, zwei, drei oder vier der genannten Legierungselemente ergibt. Die Elemente Ti, Nb, Zr, V und W sorgen durch ihre gegenüber Cr bevorzugte Bindung an N dafür, dass der ferritbildende freie Cr-Gehalt nicht durch Nitridbildung reduziert wird. Zudem können diese Legierungselemente C binden, so dass die Bildung spröder kappa-Karbide (Fe-Al-Karbide) vermieden werden können. Ti, Nb, Zr, V und/oder W können auch nur als Verunreinigung und/oder normale Begleiter enthalten sein. Vorzugsweise ist der FeAlCr-Stahl Nb-frei. In addition, it may be advantageous if a proportion of Ti, Nb, Zr, V and / or W is present, which in total is greater than the inevitable impurities due to production, wherein the alloying elements are each limited to a maximum of 1 wt .-% , and in particular in the range of 0, 1 to 2 wt .-%, preferably 0.25 to 1.5 wt .-% and particularly preferably 0.3 to 1.2 wt .-%, based on the total amount of Ti, Nb, Zr, V and W can lie. In this case, it is not necessary for the FeAlCr steel to contain all five of said alloying elements, but it is also possible that the content results only from one, two, three or four of said alloying elements. The elements Ti, Nb, Zr, V and W, by virtue of their preferred binding to N over Cr, ensure that the ferrite-forming free Cr content is not reduced by nitride formation. In addition, these can Alloy elements C bind, so that the formation of brittle kappa carbides (Fe-Al-carbides) can be avoided. Ti, Nb, Zr, V and / or W may also be included only as an impurity and / or normal companion. Preferably, the FeAlCr steel is Nb-free.
Beispielhafte Vertreter für FeAlCr Stähle mit einem ferritischen, umwandlungsfreien Gefüge sind beispielsweise aus der Offenlegungsschrift WO 2013/178629 AI der Anmelderin bekannt. Exemplary representatives of FeAlCr steels with a ferritic, conversion-free structure are known, for example, from the published patent application WO 2013/178629 A1 of the Applicant.
Gemäß einer weiteren Ausgestaltung des Warmumformverbundmaterials besteht der härtbare Stahl der Kernlage neben Fe und herstellungsbedingt unvermeidbaren Verunreinigungen in Gew.-% aus According to a further embodiment of the hot-forming composite material, the hardenable steel of the core layer consists of Fe and production-related unavoidable impurities in% by weight
C: 0,06 - 0,8 %, C: 0.06 - 0.8%,
Si: bis 0,5 %,  Si: up to 0.5%,
Mn: 0,5 - 3 %,  Mn: 0.5-3%,
P: bis 0,06 %,  P: up to 0.06%,
S: bis 0,03 %,  S: up to 0.03%,
AI: bis 0,2 %,  AI: up to 0.2%,
Cr+Mo: bis 1 %,  Cr + Mo: up to 1%,
Cu: bis 0,2%,  Cu: up to 0.2%,
N: bis 0,01 %,  N: up to 0.01%,
Nb+Ti: bis 0,2 %,  Nb + Ti: up to 0.2%,
Ni: bis 0,4 %,  Ni: up to 0.4%,
V: bis 0,2 %,  V: up to 0.2%,
B: bis 0,01 %,  B: up to 0.01%,
As: bis 0,02 %,  As: to 0.02%,
Ca: bis 0,01 %,  Ca: up to 0.01%,
Co: bis 0,02 %,  Co: up to 0.02%,
Sn: bis 0,05 %.  Sn: up to 0.05%.
Die Angaben der Legierungselemente beziehen sich insbesondere auf den Zustand (Anlieferungszustand) vor der Erzeugung des Werkstoffverbundes. The details of the alloying elements relate in particular to the state (state of delivery) before the production of the composite material.
C ist ein festigkeitssteigerndes Legierungselement und trägt mit zunehmendem Gehalt zur Festigkeitssteigerung bei, so dass ein Gehalt von mindestens 0,06 Gew.-%, insbesondere von mindestens 0, 12 Gew.-%, vorzugsweise von mindestens 0,2 Gew.-%, weiter bevorzugt von mindestens 0,28 Gew.-%, weiter bevorzugt von mindestens 0,33 Gew.-% weiter bevorzugt von mindestens 0,37 Gew.-%, besonders bevorzugt von mindestens 0,42 Gew.-% vorhanden ist, um die gewünschte Festigkeit zu erreichen bzw. einzustellen. Mit höherer Festigkeit nimmt auch die Sprödigkeit zu, so dass der Gehalt auf maximal 0,8 Gew.-%, insbesondere maximal 0,75 Gew.-%, vorzugsweise maximal 0,68 Gew.-%, weiter bevorzugt maximal 0,65 Gew.-%, besonders bevorzugt maximal 0,62 Gew.-% beschränkt ist, um die Werkstoffeigenschaften nicht negativ zu beeinflussen und eine ausreichende Schweißbarkeit sicherzustellen. C is a strength-increasing alloying element and contributes with increasing content to increase the strength, so that a content of at least 0.06 wt .-%, in particular of at least 0.12 wt%, preferably at least 0.2 wt%, more preferably at least 0.28 wt%, more preferably at least 0.33 wt%, even more preferably at least 0.37 Wt .-%, particularly preferably of at least 0.42 wt .-% is present in order to achieve or set the desired strength. With a higher strength, the brittleness increases, so that the content to a maximum of 0.8 wt .-%, in particular at most 0.75 wt .-%, preferably at most 0.68 wt .-%, more preferably at most 0.65 wt .-%, more preferably not more than 0.62 wt .-% is limited in order not to adversely affect the material properties and to ensure sufficient weldability.
Si ist ein Legierungselement, das zur Mischkristallhärtung beiträgt und wirkt sich je nach Gehalt positiv in einer Festigkeitssteigerung aus, so dass ein Gehalt von mindestens 0,05 Gew.-% vorhanden ist. Das Legierungselement ist auf maximal 0,5 Gew.-%, insbesondere maximal 0,45 Gew.-%, vorzugsweise maximal 0,4 Gew.-% beschränkt, um eine ausreichende Walzbarkeit sicherzustellen. Si is an alloying element that contributes to solid solution hardening and, depending on the content, has a positive effect on an increase in strength, so that a content of at least 0.05% by weight is present. The alloying element is limited to a maximum of 0.5% by weight, in particular a maximum of 0.45% by weight, preferably a maximum of 0.4% by weight, in order to ensure sufficient rolling capability.
Mn ist ein Legierungselement, das zur Härtbarkeit und zur Erhöhung der Verarbeitungszeit im Warmumformprozess durch Umwandlungsverzögerung beiträgt und sich positiv auf die Zugfestigkeit auswirkt, insbesondere zum Abbinden von S zu MnS, so dass ein Gehalt von mindestens 0,5 Gew.-% vorhanden ist. Das Legierungselement ist auf maximal 3 Gew.-%, insbesondere maximal 2,5 Gew.-%, vorzugsweise maximal 2,2 Gew.-% beschränkt, um eine ausreichende Schweißbarkeit sicherzustellen. In Verbindung mit einem C-Gehalt von kleiner 0,2 Gew.-%, insbesondere von kleiner 0, 12 Gew.-% ist Mn mit mindestens 1,5 Gew.-%, insbesondere mit mindestens 1,7 Gew.-% zulegiert, um eine Härtbarkeit zu gewährleisten. Liegt C mit mindestens 0,2 Gew.-% vor, kann Mn auf maximal 2 Gew.-%, insbesondere maximal 1,5 Gew.-% reduziert werden. Mn is an alloying element that contributes to hardenability and increase working time in the hot forming process by conversion delay and has a positive effect on tensile strength, especially for setting S to MnS, so that a content of at least 0.5 wt% is present. The alloying element is limited to a maximum of 3% by weight, in particular a maximum of 2.5% by weight, preferably a maximum of 2.2% by weight, in order to ensure sufficient weldability. In conjunction with a C content of less than 0.2 wt .-%, in particular of less than 0, 12 wt .-% Mn is at least 1.5 wt .-%, in particular at least 1.7 wt .-% alloyed to ensure hardenability. If C is at least 0.2% by weight, Mn can be reduced to a maximum of 2% by weight, in particular a maximum of 1.5% by weight.
AI kann als Legierungselement zur Desoxidation beitragen, wobei ein Gehalt mit mindestens 0,01 Gew.-%, insbesondere mit 0,015 Gew.-% vorhanden sein kann. Das Legierungselement ist auf maximal 0,2 Gew.-%, insbesondere maximal 0, 15 Gew.-%, vorzugsweise maximal 0, 1 Gew.-% beschränkt, um Ausscheidungen im Werkstoff insbesondere in Form von nichtmetallischen oxidischen Einschlüssen im Wesentlichen zu reduzieren und/oder zu vermeiden, welche negativ die Werkstoffeigenschaften beeinflussen können. Beispielsweise kann der Gehalt zwischen 0,02 und 0,06 Gew.-% eingestellt sein. Cr kann als Legierungselement je nach Gehalt auch zur Einstellung der Festigkeit, insbesondere positiv zur Härtbarkeit beitragen, beispielsweise mit einem Gehalt von mindestens 0,05 Gew.-%. Das Legierungselement ist auf maximal 1 Gew.-%, insbesondere maximal 0,8 Gew.-%, vorzugsweise maximal 0,7 Gew.-% beschränkt, um eine ausreichende Schweißbarkeit sicherzustellen. Al may contribute as an alloying element for deoxidation, wherein a content of at least 0.01 wt .-%, in particular 0.015 wt .-% may be present. The alloying element is limited to a maximum of 0.2 wt .-%, in particular at most 0, 15 wt .-%, preferably at most 0, 1 wt .-% to substantially reduce precipitates in the material, in particular in the form of non-metallic oxide inclusions and / or to avoid which can adversely affect the material properties. For example, the content can be adjusted between 0.02 and 0.06 wt .-%. Depending on the content, Cr may also contribute to the setting of the strength, in particular to the hardenability, as an alloying element, for example with a content of at least 0.05% by weight. The alloying element is limited to a maximum of 1% by weight, in particular a maximum of 0.8% by weight, preferably a maximum of 0.7% by weight, in order to ensure sufficient weldability.
B kann als Legierungselement zur Härtbarkeit und Festigkeitssteigerung beitragen, insbesondere wenn N abgebunden wird und kann mit einem Gehalt von mindestens 0,0008 Gew.-%, insbesondere von mindestens 0,001 Gew.-% vorhanden sein. Das Legierungselement kann auf maximal 0,01 Gew.-%, insbesondere auf maximal 0,008 Gew.-% beschränkt, da höhere Gehalte sich nachteilig auf die Werkstoffeigenschaften auswirken und eine Reduzierung der Härte und/oder Festigkeit im Werkstoff zur Folge hätte. B can contribute to hardenability and increase in strength as an alloying element, in particular when N is set and can be present at a level of at least 0.0008% by weight, in particular of at least 0.001% by weight. The alloying element can be limited to a maximum of 0.01% by weight, in particular to a maximum of 0.008% by weight, since higher contents have an adverse effect on the material properties and would result in a reduction of hardness and / or strength in the material.
Ti und Nb können als Legierungselemente einzeln oder in Kombination zur Kornfeinung und/oder N-Abbindung zulegiert werden, insbesondere wenn Ti mit einem Gehalt von mindestens 0,005 Gew.-% vorhanden ist. Zur vollständigen Abbindung von N wäre der Gehalt an Ti mit mindestens 3,42*N vorzusehen. Die Legierungselemente sind in Kombination auf maximal 0,2 Gew.-%, insbesondere maximal 0, 15 Gew.-%, vorzugsweise maximal 0, 1 Gew.- % beschränkt, da höhere Gehalte sich nachteilig auf die Werkstoffeigenschaften, insbesondere sich negativ auf die Zähigkeit des Werkstoffs auswirken. Ti and Nb may be alloyed as alloying elements singly or in combination for grain refining and / or N-setting, especially when Ti is present at a level of at least 0.005 wt%. For complete setting of N, the content of Ti should be at least 3.42 * N. The alloying elements in combination are limited to a maximum of 0.2% by weight, in particular not more than 0.15% by weight, preferably not more than 0.1% by weight, since higher contents have a disadvantageous effect on the material properties, in particular adversely on the Toughness of the material.
Mo, V, Cu, Ni, Sn, Ca, Co, As, N, P oder S sind Legierungselemente, die einzeln oder in Kombination, wenn sie nicht gezielt zur Einstellung spezieller Eigenschaften zulegiert werden, zu den Verunreinigungen gezählt werden können. Die Gehalte sind beschränkt auf maximal 0,2 Gew.-% Mo, auf maximal 0,2 Gew.-% V, auf maximal 0,2 Gew.-% Cu, auf maximal 0,4 Gew.-% Ni, auf maximal 0,05 Gew.-% Sn, auf maximal 0,01 Gew.-% Ca, auf maximal 0,02 Gew.-% Co, auf maximal 0,02 Gew.-% As, auf maximal 0,01 Gew.-% N, auf maximal 0,06 Gew.-% P, auf maximal 0,03 Gew.-% S. Mo, V, Cu, Ni, Sn, Ca, Co, As, N, P, or S are alloying elements that can be counted as impurities individually or in combination, unless they are specifically added to set specific properties. The contents are limited to a maximum of 0.2% by weight Mo, to a maximum of 0.2% by weight V, to a maximum of 0.2% by weight Cu, to a maximum of 0.4% by weight Ni, to a maximum 0.05% by weight of Sn, to a maximum of 0.01% by weight of Ca, to a maximum of 0.02% by weight of Co, to a maximum of 0.02% by weight of As, to a maximum of 0.01% by weight. % N, to a maximum of 0.06 wt% P, to a maximum of 0.03 wt% S.
Der härtbare Stahl der Kernlage des Warmumformverbundmaterials weist im pressgehärteten Zustand eine Zugfestigkeit > 500 MPa und/oder eine Härte > 170 HV10, insbesondere eine Zugfestigkeit > 1300 MPa und/oder eine Härte > 450 HV10, vorzugsweise eine Zugfestigkeit > 1700 MPa und/oder eine Härte > 500 HV10, weiter bevorzugt eine Zugfestigkeit > 1900 MPa und/oder eine Härte > 575 HV10, besonders bevorzugt eine Zugfestigkeit > 2100 MPa und/oder eine Härte > 630 HV10 auf. HV entspricht der Vickershärte und wird nach DIN EN ISO 6507-1 :2005 bis -4: 2005 ermittelt. Liegt die Zugfestigkeit beispielsweise oberhalb von 1000 MPa, insbesondere oberhalb von 1300 MPa, kann das Gefüge im pressgehärteten Zustand beispielsweise mindestens zu 90%, vorzugsweise mindestens zu 95%, weiter bevorzugt mindestens zu 98% aus Martensit und/oder einem Mischgefüge aus Martensit- Bainit bestehen und kann im Übergangsbereich zur Kernlage auch Ferrit enthalten. Bei einer Zugfestigkeit unterhalb von 1000 MPa reduziert sich der Anteil an Martensit und/oder das Mischgefüge aus Martensit-Bainit entsprechend. The hardenable steel of the core layer of the hot forging composite material has a tensile strength> 500 MPa and / or a hardness> 170 HV10 in the press-hardened state, in particular a tensile strength> 1300 MPa and / or a hardness> 450 HV10, preferably a tensile strength> 1700 MPa and / or a Hardness> 500 HV10, more preferably a tensile strength> 1900 MPa and / or a hardness> 575 HV10, more preferably a tensile strength> 2100 MPa and / or a hardness> 630 HV10. HV corresponds to the Vickers hardness and is according to DIN EN ISO 6507-1: 2005 to -4: 2005 determined. If the tensile strength is, for example, above 1000 MPa, in particular above 1300 MPa, the microstructure in the press-hardened state can be for example at least 90%, preferably at least 95%, more preferably at least 98% martensite and / or a martensite bainite mixed structure exist and may also contain ferrite in the transition region to the core layer. With a tensile strength below 1000 MPa, the proportion of martensite and / or the martensite-bainite mixed structure is correspondingly reduced.
Beispielhafte Vertreter für härtbare Stähle sind handelsübliche Stähle der Gruppe aus der DIN- Norm DIN EN 10883-2, beispielsweise der Güte C22, C35, C45, C55, C60, manganhaltige Stähle (DIN EN 10883-3), insbesondere der Güte 20MnB5, 30MnB5, bzw. 37MnB5, 42CrMo4 nach DIN EN 10263-4 und weiteren Güten wie, z. B. 20MnB8, 22MnB5, 40MnB4, sowie Einsatzstähle oder lufthärtende Stähle. Exemplary representatives of hardenable steels are commercially available steels of the group from the DIN standard DIN EN 10883-2, for example the quality C22, C35, C45, C55, C60, manganese-containing steels (DIN EN 10883-3), in particular the grade 20MnB5, 30MnB5 , or 37MnB5, 42CrMo4 according to DIN EN 10263-4 and other grades such as, for. 20MnB8, 22MnB5, 40MnB4, as well as case-hardened steels or air-hardening steels.
Gemäß einer weiteren Ausgestaltung des Warmumformverbundmaterials weisen die Decklagen jeweils eine Materialdicke < 22 %, insbesondere < 17 %, vorzugsweise < 12 %, besonders bevorzugt < 9 % bezogen auf die Gesamtmaterialdicke des Warmumformverbundmaterials auf. Die Decklagen weisen eine Materialdicke von jeweils mindestens 1 %, insbesondere mindestens 2 %, vorzugsweise mindestens 4 %, besonders bevorzugt mindestens 5 % pro Seite bezogen auf die Gesamtmaterialdicke des Warmumformverbundmaterials auf. Das Warmumformverbundmaterial respektive der dreilagige Werkstoffverbund weist eine Gesamtmaterialdicke zwischen 0,5 und 8,0 mm, insbesondere zwischen 0,8 und 5,0 mm und vorzugsweise zwischen 1,2 und 4,0 mm auf. According to a further embodiment of the hot-forming composite material, the cover layers each have a material thickness of <22%, in particular <17%, preferably <12%, particularly preferably <9%, based on the total material thickness of the hot-forming composite material. The cover layers have a material thickness of in each case at least 1%, in particular at least 2%, preferably at least 4%, particularly preferably at least 5%, per side, based on the total material thickness of the hot-forming composite material. The hot-forming composite material or the three-layer material composite has a total material thickness between 0.5 and 8.0 mm, in particular between 0.8 and 5.0 mm, and preferably between 1.2 and 4.0 mm.
Gemäß einem zweiten Aspekt betrifft die Erfindung ein Verfahren zum Herstellen eines warmwalzplattierten Warmumformverbundmaterials aus einem zumindest dreilagigen Werkstoffverbund umfassend eine Kernlage aus einem härtbaren Stahl und zwei stoffschlüssig mit der Kernlage verbundenen Decklagen (1.2) aus einem ferritisch, umwandlungsfreien FeAlCr- Stahl, das Verfahren umfassend folgende Schritte: According to a second aspect, the invention relates to a method for producing a hot-rolled hot-forming composite material from an at least three-layer composite material comprising a core layer of a hardenable steel and two cohesively connected to the core layer cover layers (1.2) of a ferritic, conversion-free FeAlCr steel, the method comprising the following Steps:
- Bereitstellen einer Lage aus einem härtbaren Stahl und mindestens zwei Lagen aus einem ferritisch, umwandlungsfreien FeAlCr-Stahl, - Aufeinanderstapeln der bereitgestellten Lagen derart, dass die Lage aus dem härtbaren Stahl eine Kernlage bildet und die beiden Lagen aus dem ferritisch, umwandlungsfreien Stahl als Decklagen die Kernlage zwischen sich aufnehmen, Providing a layer of a hardenable steel and at least two layers of a ferritic, non-transforming FeAlCr steel, Stacking up the layers provided in such a way that the layer of hardenable steel forms a core layer and the two layers of ferritic, non-transforming steel absorb the core layer between them as cover layers,
- Zumindest bereichsweises stoffschlüssiges Verbinden der Kanten zwischen den einzelnen Lagen zur Erzeugung eines Vorverbundes, insbesondere mittels Schweißen, - At least partially cohesive bonding of the edges between the individual layers to produce a pre-bond, in particular by welding,
- Erwärmen des Vorverbundes in einem Ofen auf mindestens 1200°C, Heating the pre-bond in an oven to at least 1200 ° C,
- Warmwalzen des erwärmten Vorverbundes in einem oder mehreren Schritten zu einem coilfähigen Warmband, Hot rolling of the heated preliminary composite in one or more steps to form a coil-capable hot strip,
- Optionales Kaltwalzen des Warmbandes in einem oder mehreren Schritten zu einem Kaltband. - Optional cold rolling of the hot strip in one or more steps to a cold strip.
Die Vorgehensweise zur Herstellung eines Warmumformverbundmaterials kann in Analogie zu der Lehre gemäß der DE 10 2005 006 606 B3 erfolgen. Vor dem Aufeinanderstapeln der einzelnen Lagen können die Oberflächen der Lagen jeweils einer Säuberung zur Entfernung von Fremdstoffen auf der Oberfläche und/oder einer spanenden Bearbeitung insbesondere zur Einstellung einer vordefinierten Planheit unterzogen werden. Die Lagen werden beispielsweise in Form von Blechen, Platten, Vorbrammen oder Brammen zusammengebaut. Die Lage aus härtbarem Stahl und die Lagen aus FeAlCr-Stahl weisen bevorzugt die chemischen Legierungselemente auf, wie sie zuvor weiter oben definiert sind. Alle vorgenannten Vorteile gelten auch in Zusammenhang mit dem erfindungsgemäßen Verfahren zur Herstellung eines Warmumformverbundmaterials. The procedure for producing a thermoforming composite material can be carried out in analogy to the teaching according to DE 10 2005 006 606 B3. Before stacking the individual layers, the surfaces of the layers can each be subjected to a cleaning operation for removing foreign substances on the surface and / or a machining, in particular for setting a predefined flatness. The layers are assembled, for example in the form of sheets, plates, slabs or slabs. The layer of hardenable steel and the layers of FeAlCr steel preferably have the chemical alloying elements as previously defined above. All of the aforementioned advantages also apply in connection with the process according to the invention for producing a hot-formed composite material.
Gemäß einem dritten Aspekt betrifft die Erfindung ein Bauteil hergestellt aus einem erfindungsgemäßen Warmumformverbundmaterial mittels Presshärten oder mehrstufigen Warmumformverfahrens, insbesondere zur Herstellung einer Komponente für den Automobilbau, Eisenbahn-, Schiffbau oder Luft- und Raumfahrt. Das Presshärten kann mittels direkter oder indirekter Warmumformung erfolgen. Unter einem mehrstufigen Warmumformverfahren ist ein Warmumformen in mindestens zwei Werkzeugen und/oder in mindestens zwei Operationsstufen mit optionalem Beschnitt und anschließender Presshärtung zu verstehen. Beispielhaft sei auf die EP 3 067 128 AI verwiesen. Insbesondere weist das Bauteil nach dem Presshärten oder mehrstufigen Warmumformverfahren eine Aluminium- oxidschicht auf, insbesondere mit einer Dicke bis zu 1000 nm, insbesondere bis zu 300 nm, vorzugsweise bis zu 200 nm, besonders bevorzugt bis zu 150 nm auf. According to a third aspect, the invention relates to a component produced from a hot-formed composite material according to the invention by means of press-hardening or multi-stage hot-forming method, in particular for producing a component for the automotive, railway, shipbuilding or aerospace industry. Press hardening can be done by direct or indirect hot working. A multi-stage hot forming process is to be understood to mean hot forming in at least two tools and / or in at least two operating stages with optional trimming and subsequent press hardening. By way of example, reference is made to EP 3 067 128 A1. In particular, after the press-hardening or multi-stage hot-forming process, the component has an aluminum oxide layer, in particular with a thickness of up to 1000 nm, in particular up to 300 nm, preferably up to 200 nm, more preferably up to 150 nm.
Gemäß einem vierten Aspekt betrifft die Erfindung eine Verwendung eines Bauteils hergestellt aus dem erfindungsgemäßen Warmumformverbundmaterial in einer Karosserie oder im Fahrwerk eines landgebundenen Fahrzeugs. Hierbei handelt es sich vorzugsweise um Personenkraftwagen, Nutzfahrzeuge oder Busse, sei es mit Verbrennungsmotor, rein elektrisch betriebene oder hybridbetriebene Fahrzeuge. Die Bauteile können als Längs-, Querträger oder Säulen im landgebundenen Fahrzeug verwendet werden, beispielsweise sind sie als Profile ausgebildet, insbesondere als Crashprofil im Stoßfänger, Schweller, Seitenaufprallträger oder in Bereichen, in denen keine bis geringe Deformationen/Intrusionen im Crashfall gefordert werden oder können im Fahrwerksbereich als Querlenker, Stabilisatoren oder Verbundlenkerhinterachse ausgebildet sein. According to a fourth aspect, the invention relates to a use of a component produced from the hot-formed composite material according to the invention in a body or in the chassis of a land-bound vehicle. These are preferably passenger cars, commercial vehicles or buses, be it with an internal combustion engine, purely electrically powered or hybrid-powered vehicles. The components can be used as longitudinal, transverse beams or columns in land-bound vehicle, for example, they are designed as profiles, in particular as a crash profile in the bumper, sill, side impact or in areas where no to small deformations / intrusions in the event of a crash are required or can be designed in the chassis as a wishbone, stabilizers or torsion beam rear axle.
Kurze Beschreibung der Zeichnungen (Brief Description of Drawings) Short description of the drawings (Brief Description of Drawings)
Im Folgenden wird die Erfindung anhand einer Zeichnung näher erläutert. Die Zeichnung zeigt:  In the following the invention will be explained in more detail with reference to a drawing. The drawing shows:
Fig. 1) einen schematischen Schnitt durch ein erfindungsgemäßes Warmumformverbundmaterial. Fig. 1) shows a schematic section through an inventive thermoforming composite material.
Beschreibung der bevorzugten Ausführungsformen (Best Mode for Carrying out the Invention) Description of the Preferred Embodiments (Best Mode for Carrying Out the Invention)
In der einzigen Figur ist eine schematische Schnittdarstellung durch ein erfindungsgemäßes Warmumformverbundmaterial (1) gezeigt. Das erfindungsgemäße Warmumformverbundmaterial (1) umfasst eine Kenlage (1.1) aus einer härtbaren Stahl mit einem Kohlenstoffanteil C von mindestens 0,06 Gew.-%, welche im pressgehärteten Zustand eine Zugfestigkeit > 500 MPa und/oder eine Härte > 170 HV10, insbesondere eine Zugfestigkeit > 1300 MPa und/oder eine Härte > 450 HV10, vorzugsweise eine Zugfestigkeit > 1700 MPa und/oder eine Härte > 520 HV10, weiter bevorzugt eine Zugfestigkeit > 1900 MPa und/oder eine Härte > 575 HV10 aufweist, zwei stoffschlüssig mit der Kernlage (1.1) verbundenen Decklagen (1.2) aus einem ferritschen, umwandlungsfreien FeAlCr-Stahl mit einem Aluminiumgehalte AI zwischen 3 und 7 Gew.-% und einem Chromgehalt Cr zwischen 0, 1 und 12 Gew.-%. Die Materialdicke der Decklagen (1.3) beträgt pro Seite mindestens 1 % und maximal 22 %, vorzugsweise mindestens 4 % und maximal 12 % bezogen auf die Gesamtmaterialdicke des Warmumform- verbundmaterials (1), wobei das Warmumformverbundmaterial (1) beispielsweise eine Gesamtmaterialdicke zwischen 0,5 und 8 mm aufweisen kann. The single FIGURE shows a schematic sectional view through a hot-formed composite material (1) according to the invention. The hot-formed composite material (1) according to the invention comprises a core layer (1.1) made of a hardenable steel having a carbon content C of at least 0.06 wt .-%, which in the press-hardened state, a tensile strength> 500 MPa and / or a hardness> 170 HV10, in particular a Tensile strength> 1300 MPa and / or a hardness> 450 HV10, preferably a tensile strength> 1700 MPa and / or a hardness> 520 HV10, more preferably a tensile strength> 1900 MPa and / or a hardness> 575 HV10, two cohesively with the core layer (1.1) joined cover layers (1.2) of a ferrite, conversion-free FeAlCr steel having an aluminum content AI between 3 and 7 wt .-% and a chromium content Cr between 0, 1 and 12 wt .-%. The material thickness of the cover layers (1.3) is at least 1% per side and a maximum of 22%, preferably at least 4% and a maximum of 12% based on the total material thickness of the hot forging composite material (1), wherein the thermoforming composite material (1), for example, may have a total material thickness between 0.5 and 8 mm.
Aus handelsüblichen Stahlflachprodukten wurde mittels Warmwalzplattieren ein Warmumformverbundmaterial erzeugt, das einen dreilagigen Werkstoffverbund aufwies. Als Decklagen wurde ein Stahl der Bezeichnung Fe-5,4AI-6Cr-0,04Ti und als Kernlage wurde ein härtbarer Stahl der Bezeichnung 37MnB5 verwendet. From commercial flat steel products, a hot forming composite material was produced by means of hot rolling, which had a three-layer composite material. The cover layers used were steel Fe-5,4AI-6Cr-0,04Ti and the core layer used was a hardenable steel of the designation 37MnB5.
Dabei wurden jeweils Blechzuschnitte (Brammen) zu einer Kernlage mit zwei Decklagen aufeinander gestapelt, welche zumindest bereichsweise entlang ihrer Kanten stoffschlüssig, vorzugsweise mittels Schweißen zu einem Vorverbund miteinander verbunden wurden. Durch den im Vergleich zu chemisch beständigen Stählen (Chromstähle) geringeren Cr-Gehalt konnte der Paketbau weniger aufwendig hergestellt werden. Der Vorverbund wurde in einem Ofen auf Temperatur > 1200°C gebracht und in mehreren Schritten zu einem Werkstoffverbund mit einer Gesamtmaterialdicke von 3 mm warmgewalzt und anschließend zu einem Kaltband mit 1,5 mm weiterverarbeitet. In this case, each sheet metal blanks (slabs) were stacked to form a core layer with two cover layers, which were at least partially joined together along their edges cohesively, preferably by welding to a pre-bond. Due to the lower Cr content compared to chemically resistant steels (chromium steels), package construction was less complicated. The precoat was brought to a temperature of> 1200 ° C in an oven and hot rolled in several steps to a composite material with a total material thickness of 3 mm and then further processed to form a cold strip of 1.5 mm.
Aus dem hergestellten Warmumformverbundmaterial wurden Platinen abgeteilt. Die Platinen wurden auf Austenitisierungstemperatur, insbesondere oberhalb von Ac3 (bezogen auf die Kernlage) mittels Induktion erwärmt bzw. durchwärmt und anschließend in einem gekühlten Werkzeug zu Bauteilen warm umgeformt und abgekühlt. Die Abkühlraten lagen bei > 30 K/s. Blanks were separated from the hot-formed composite material produced. The blanks were heated to Austenitisierungstemperatur, in particular above A c3 (based on the core layer) by induction or heated and then hot formed into a cooled tool to components and cooled. The cooling rates were> 30 K / s.
Mittels EDX-Analyse im Rasterelektronenmikroskop wurden die erzeugten Bauteile näher untersucht und es konnte im Wesentlichen keine Aufhärtung, sprich keine Erhöhung der Konzentration des Kohlenstoffs in den Decklagen festgestellt werden. Über den Querschnitt der Kernlage hatte sich ein Kohlenstoffprofil mit einer im Wesentlichen höheren Konzentration des Kohlenstoffs im Randbereich (grenzflächennah) als in der Mitte der Kernlage ausgebildet. Am Übergang der beiden Lagen reicherte sich eine C-reiche Phase an. Durch die aus einer ferritischen, umwandlungsfreien Gitterstruktur mit entsprechender Kohlenstofflöslichkeit bestehenden Decklagen konnte ein Eindiffundieren des Kohlenstoffs aus der Kernlage durch das freie Chrom der Decklagen in Form von Chromkarbiden im Wesentlichen grenzflächennah abgebunden wurden. Im grenzflächenfernen Bereich in Richtung Zentrum bzw. Mitte der Kernlage kam es im Wesentlichen zu keiner Veränderung der chemischen Legierungselemente im Vergleich zum Ausgangzustand bzw. Anlieferungszustand. Die Kernlage war über die Dicke im Wesentlichen vollständig aus Martensit und am Übergang zu der Decklage enthielt das Gefüge zusätzlich Anteile an Bainit und/oder Ferrit. Die Decklage behielt ihr Ausgangsgefüge, welches sie zum Zeitpunkt der Bereitstellung vor der Fertigung des Werkstoffverbundes und der Weiterverarbeitung zu einem Bauteil hatte, im Wesentlichen bei, so dass keine Umwandlung erfolgte. Die eingesetzten Decklagen aus FeAlCr-Stahl nehmen positiv Einfluss auf die Biegeeigenschaften des Werkstoffverbundes respektive Warmumformverbundmaterials, da sie zusätzlich zur eigenen geringen Festigkeit und damit hohen Duktilität die Möglichkeit bietet, ablaufende Diffusionsprozesse so zu beeinflussen, dass in der Kernlage des Werkstoffverbundes, der bisher eine durchgängig hohe Festigkeit besitzt, lokal Bereiche mit geringerer Festigkeit entstehen. Die Materialdicke der Decklagen betrug pro Seite 6% bezogen auf die Gesamtmaterialdicke des Warmumformverbundmaterials, so dass die Kernlage eine Materialdicke von 88 % bezogen auf die Gesamtmaterialdicke aufwies. Die Dicke der sich auf der Oberfläche des im Zuge des Presshärtens gebildeten Aluminiumoxidschicht belief sich auf weniger als 150 nm. By means of EDX analysis in the scanning electron microscope, the components produced were examined more closely and essentially no hardening, that is to say no increase in the concentration of the carbon in the cover layers, could be ascertained. Over the cross-section of the core layer, a carbon profile with a substantially higher concentration of carbon had formed in the edge region (near the interface) than in the middle of the core layer. At the transition of the two layers enriched a C-rich phase. Due to the existing of a ferritic, conversion-free lattice structure with appropriate carbon solubility cover layers indiffusion of the carbon from the core layer by the free chromium of the top layers in the form of chromium carbides were essentially tied off near the surface. In the area remote from the center towards the center or center of the core layer, there was essentially no change in the chemical alloying elements in comparison to the initial state or delivery state. The core layer was essentially entirely of martensite over the thickness and at the transition to the top layer, the microstructure contained additional amounts of bainite and / or ferrite. The cover layer essentially retained its initial structure, which it had at the time of preparation prior to production of the material composite and further processing into a component, so that no conversion took place. The cover layers made of FeAlCr steel have a positive influence on the bending properties of the composite material or hotforming composite material, because in addition to its own low strength and thus high ductility, it offers the possibility of influencing the diffusion processes that occur in the core situation of the composite material high strength, local areas of lesser strength arise. The material thickness of the cover layers per side was 6% based on the total material thickness of the hot forging composite material, so that the core layer had a material thickness of 88% based on the total material thickness. The thickness of the aluminum oxide layer formed on the surface of the aluminum oxide layer formed during the press-hardening was less than 150 nm.
Die Erfindung ist nicht auf das in der Zeichnung dargestellte Ausführungsbeispiel beschränkt. Vielmehr kann das erfindungsgemäße Warmumformverbundmaterial auch Teil eines Tailored Product, beispielsweise Teil eines Tailored Welded Blank und/oder Tailored Rolled Blank sein und auch mehr als drei Lagen aufweisen. Außerdem kann ein Bauteil auch mittels eines mehrstufigen Warmumformverfahrens hergestellt werden. The invention is not limited to the embodiment shown in the drawing. On the contrary, the hot-formed composite material according to the invention can also be part of a tailored product, for example part of a tailored welded blank and / or tailored rolled blank, and also have more than three layers. In addition, a component can also be produced by means of a multi-stage hot forming process.

Claims

Ansprüche claims
1. Warmumformverbundmaterial (1) aus einem zumindest dreilagigen Werkstoffverbund umfassend eine Kernlage (1.1) aus einem härtbaren Stahl und zwei stoffschlüssig mit der Kernlage (1.1) verbundenen Decklagen (1.2) aus einem ferritisch, umwandlungsfreien FeAlCr-Stahl. 1. hot forming composite material (1) of an at least three-layer composite material comprising a core layer (1.1) of a hardenable steel and two cohesively connected to the core layer (1.1) cover layers (1.2) of a ferritic, conversion-free FeAlCr steel.
2. Warmumformverbundmaterial nach Anspruch 1, dadurch gekennzeichnet, dass der ferritisch, umwandlungsfreie FeAlCr-Stahl der Decklagen (1.2) neben Fe und herstellungsbedingt unvermeidbaren Verunreinigungen in Gew.-% aus 2. hot forming composite material according to claim 1, characterized in that the ferritic, conversion-free FeAlCr steel of the cover layers (1.2) in addition to Fe and production-related unavoidable impurities in wt .-% of
C: bis 0, 15 %, C: to 0, 15%,
AI: 2 bis 9 %,  AI: 2 to 9%,
Cr: 0, 1 bis 12 %,  Cr: 0, 1 to 12%,
Si: bis 2 %,  Si: up to 2%,
Mn: bis 1 %,  Mn: up to 1%,
Mo: bis 2 %,  Mo: up to 2%,
Co: bis 2 %  Co: up to 2%
P: bis 0, 1 %,  P: to 0, 1%,
S: bis 0,03 %,  S: up to 0.03%,
Ti: bis 1 %,  Ti: up to 1%,
Nb: bis 1 %,  Nb: up to 1%,
Zr: bis 1 %,  Zr: up to 1%,
V: bis 1 %,  V: up to 1%,
W: bis 1 % besteht.  W: up to 1% exists.
3. Warmumformverbundmaterial nach einem der vorgenannten Ansprüche, dadurch gekennzeichnet, dass der härtbare Stahl der Kernlage (1.1) neben Fe und herstellungsbedingt unvermeidbaren Verunreinigungen in Gew.-% aus 3. hot forming composite material according to one of the preceding claims, characterized in that the curable steel of the core layer (1.1) in addition to Fe and production-related unavoidable impurities in wt .-% of
C: 0,06 - 0,8 %, C: 0.06 - 0.8%,
Si: bis 0,5 %,  Si: up to 0.5%,
Mn: 0,4 - 3 %,  Mn: 0.4-3%,
P: bis 0,06 %, S: bis 0,03 %, P: up to 0.06%, S: up to 0.03%,
AI: bis 0,2 %,  AI: up to 0.2%,
Cr+Mo: bis 1 %,  Cr + Mo: up to 1%,
Cu: bis 0,2 %,  Cu: up to 0.2%,
N: bis 0,01 %,  N: up to 0.01%,
Nb+Ti: bis 0,2 %,  Nb + Ti: up to 0.2%,
Ni: bis 0,4 %,  Ni: up to 0.4%,
V: bis 0,2 %,  V: up to 0.2%,
B: bis 0,01 %,  B: up to 0.01%,
As: bis 0,02 %,  As: to 0.02%,
Ca: bis 0,01 %,  Ca: up to 0.01%,
Co: bis 0,02 %,  Co: up to 0.02%,
Sn: bis 0,05 % besteht.  Sn: up to 0.05%.
4. Warmumformverbundmaterial nach einem der vorgenannten Ansprüche, dadurch gekennzeichnet, dass der Stahl der Kernlage (1.1) einen C-Gehalt zwischen 0,28 - 0,75 Gew.-%, insbesondere zwischen 0,33 - 0,68 Gew.-% aufweist. 4. hot forming composite material according to any one of the preceding claims, characterized in that the steel of the core layer (1.1) has a C content between 0.28 - 0.75 wt .-%, in particular between 0.33 - 0.68 wt .-% having.
5. Warmumformverbundmaterial nach einem der vorgenannten Ansprüche, dadurch gekennzeichnet, dass die Decklagen (1.2) jeweils eine Materialdicke zwischen 1 und 22 %, insbesondere zwischen 2 und 17 %, vorzugsweise zwischen 4 und 12 % bezogen auf die Gesamtmaterialdicke des Warmumformverbundmaterials (1) aufweisen. 5. hot forming composite material according to one of the preceding claims, characterized in that the cover layers (1.2) each having a material thickness between 1 and 22%, in particular between 2 and 17%, preferably between 4 and 12% based on the total material thickness of the hot forming composite material (1) ,
6. Warmumformverbundmaterial nach einem der vorgenannten Ansprüche, dadurch gekennzeichnet, dass der Werkstoffverbund mittels Plattieren oder mittels Gießen hergestellt ist. 6. hot forming composite material according to one of the preceding claims, characterized in that the composite material is produced by means of plating or by casting.
7. Warmumformverbundmaterial nach einem der vorgenannten Ansprüchen, dadurch gekennzeichnet, dass das Warmumformverbundmaterial (1) Teil eines Tailored Products, insbesondere Teil eines Tailored Welded Blank und/oder Tailored Rolled Blank, ist. 7. hot forming composite material according to one of the preceding claims, characterized in that the hot forming composite material (1) is part of a tailored products, in particular part of a Tailored Welded Blank and / or Tailored Rolled Blank is.
8. Verfahren zum Herstellen eines warmwalzplattierten Warmumformverbundmatenals (1) aus einem zumindest dreilagigen Werkstoffverbund umfassend eine Kernlage (1.1) aus einem härtbaren Stahl und zwei stoffschlüssig mit der Kernlage verbundenen Decklagen (1.2) aus einem ferritisch, umwandlungsfreien FeAlCr-Stahl, das Verfahren umfassend folgende Schritte: 8. A method for producing a hot-rolled hot-forming composite material (1) from an at least three-layer composite material comprising a core layer (1.1) of a hardenable steel and two cohesively bonded to the core layer cover layers (1.2) made of a ferritic, conversion-free FeAlCr steel, the method comprising the following Steps:
- Bereitstellen einer Lage aus einem härbaren Stahl und mindestens zwei Lagen aus einem ferritisch, umwandlungsfreien FeAlCr-Stahl, Providing a layer of a hardenable steel and at least two layers of a ferritic, non-transforming FeAlCr steel,
- Aufeinanderstapeln der bereitgestellten Lagen derart, dass die Lage aus dem härtbaren Stahl eine Kernlage bildet und die beiden Lagen aus dem ferritisch, umwandlungsfreien Stahl als Decklagen die Kernlage zwischen sich aufnehmen, Stacking up the layers provided in such a way that the layer of hardenable steel forms a core layer and the two layers of ferritic, non-transforming steel absorb the core layer between them as cover layers,
- Zumindest bereichsweises stoffschlüssiges Verbinden der Kanten zwischen den einzelnen Lagen zur Erzeugung eines Vorverbundes, insbesondere mittels Schweißen, - At least partially cohesive bonding of the edges between the individual layers to produce a pre-bond, in particular by welding,
- Erwärmen des Vorverbundes in einem Ofen auf mindestens 1200°C, Heating the pre-bond in an oven to at least 1200 ° C,
- Warmwalzen des erwärmten Vorverbundes in einem oder mehreren Schritten zu einem coilfähigen Warmband, Hot rolling of the heated preliminary composite in one or more steps to form a coil-capable hot strip,
- Optionales Kaltwalzen des Warmbandes in einem oder mehreren Schritten zu einem Kaltband. - Optional cold rolling of the hot strip in one or more steps to a cold strip.
9. Bauteil, hergestellt aus einem Warmumformverbundmaterial nach einem der vorgenannten Ansprüche mittels Presshärten oder mehrstufigen Warmumformverfahrens. 9. Component, made of a hot forging composite material according to one of the preceding claims by means of press hardening or multi-stage hot forming process.
10. Bauteil nach Anspruch 9, dadurch gekennzeichnet, dass das Bauteil nach dem Presshärten oder mehrstufigen Warmumformverfahren eine Aluminiumoxidschicht aufweist. 10. Component according to claim 9, characterized in that the component after the press-hardening or multi-stage hot forming process comprises an aluminum oxide layer.
11. Verwendung des Bauteils nach Anspruch 9 oder 10 in einer Karosserie oder im Fahrwerk eines landgebundenen Fahrzeugs. 11. Use of the component according to claim 9 or 10 in a body or in the chassis of a land-bound vehicle.
EP17788137.2A 2017-10-06 2017-10-06 Hot-forming composite material, production thereof, component, and use thereof Withdrawn EP3691889A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2017/075463 WO2019068341A1 (en) 2017-10-06 2017-10-06 Hot-forming composite material, production thereof, component, and use thereof

Publications (1)

Publication Number Publication Date
EP3691889A1 true EP3691889A1 (en) 2020-08-12

Family

ID=60164653

Family Applications (1)

Application Number Title Priority Date Filing Date
EP17788137.2A Withdrawn EP3691889A1 (en) 2017-10-06 2017-10-06 Hot-forming composite material, production thereof, component, and use thereof

Country Status (5)

Country Link
US (1) US20200230917A1 (en)
EP (1) EP3691889A1 (en)
KR (1) KR20200064109A (en)
CN (1) CN111183026A (en)
WO (1) WO2019068341A1 (en)

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03133630A (en) 1989-10-20 1991-06-06 Nippon Steel Corp Clad steel sheet having good formability excellent in dent resistance and surface strain resistance
DE102005006606B3 (en) 2005-02-11 2006-03-16 Thyssenkrupp Steel Ag Production of roll-plated hot roll strip, involves having rectangular plates produced from steel and placed on top of each other with surfaces of plates treated before being placed on top of each other
DE102008022709A1 (en) * 2008-05-07 2009-11-19 Thyssenkrupp Steel Ag Use of a metallic composite material in a vehicle structure
WO2012146384A1 (en) 2011-04-27 2012-11-01 Tata Steel Nederland Technology B.V. A steel strip composite and a method of making the same
WO2013178629A1 (en) * 2012-05-29 2013-12-05 Thyssenkrupp Steel Europe Ag Heat-resistant fe-al-cr steel
EP2886332B1 (en) 2013-12-20 2018-11-21 ThyssenKrupp Steel Europe AG Flat steel product, and method of producing a component of a motor vehicle body and of a motor vehicle body.
DE102014116695A1 (en) 2014-11-14 2016-05-19 Benteler Automobiltechnik Gmbh Bodywork or chassis component of a motor vehicle with corrosion protection and method for its production
EP3266531B1 (en) 2015-03-09 2019-02-27 Autotech Engineering, A.I.E. Press systems and methods
DE102015112327A1 (en) * 2015-07-28 2017-02-02 Benteler Automobiltechnik Gmbh Body or chassis component of a motor vehicle with improved crash performance and method for its production

Also Published As

Publication number Publication date
US20200230917A1 (en) 2020-07-23
KR20200064109A (en) 2020-06-05
WO2019068341A1 (en) 2019-04-11
CN111183026A (en) 2020-05-19

Similar Documents

Publication Publication Date Title
EP2271541B1 (en) Use of a metal composite material in a vehicle structure
EP2123447B1 (en) Composite material with ballistic protective effect
EP2553133B1 (en) Steel, flat steel product, steel component and method for producing a steel component
EP2228459B1 (en) Component with different stability characteristics
DE102015112327A9 (en) Body or chassis component of a motor vehicle with improved crash performance and method for its production
EP3083239A1 (en) Sheet steel product, a steel component produced from such a sheet steel product, and body for a motor vehicle
EP3589487A1 (en) Flat steel semi-finished product, method for producing a component, and use thereof
WO2018137781A1 (en) Steel material composite with inhomogeneous property distribution
EP3625045B1 (en) Hot-working material, component and use
EP3496954A1 (en) Chassis component having high durability
EP3625044B1 (en) Hot-working material, component and use
EP1865086B1 (en) Use of a steel flat product produced from a manganese boron steel and method of its production
EP3625048A1 (en) Hot-working material, component and use
EP3691889A1 (en) Hot-forming composite material, production thereof, component, and use thereof
DE102015116186A1 (en) Semi-finished product and method for producing a vehicle component, use of a semi-finished product and vehicle component
EP4283003A1 (en) Method for producing a sheet metal part
DE102019115165A1 (en) Method for producing a steel composite material
DE102017201697A1 (en) Semi-finished product, use and method for producing a cohesive connection

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: 20200302

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

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20210112