EP1069962B1 - Pieces embouties en tole d'acier a ressort, s'utilisant notamment comme element de construction legere ou element de carrosserie - Google Patents

Pieces embouties en tole d'acier a ressort, s'utilisant notamment comme element de construction legere ou element de carrosserie Download PDF

Info

Publication number
EP1069962B1
EP1069962B1 EP99907622A EP99907622A EP1069962B1 EP 1069962 B1 EP1069962 B1 EP 1069962B1 EP 99907622 A EP99907622 A EP 99907622A EP 99907622 A EP99907622 A EP 99907622A EP 1069962 B1 EP1069962 B1 EP 1069962B1
Authority
EP
European Patent Office
Prior art keywords
steel
sheet
temperature
hardened
spring
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.)
Expired - Lifetime
Application number
EP99907622A
Other languages
German (de)
English (en)
Other versions
EP1069962A1 (fr
Inventor
Roland Golle
Hartmut Hoffmann
Volker Thoms
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.)
Daimler AG
Original Assignee
DaimlerChrysler 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 DaimlerChrysler AG filed Critical DaimlerChrysler AG
Publication of EP1069962A1 publication Critical patent/EP1069962A1/fr
Application granted granted Critical
Publication of EP1069962B1 publication Critical patent/EP1069962B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals

Definitions

  • the invention relates to drawn parts made of sheet steel, in particular for motor vehicle bodies, e.g. Body skin and load-bearing Structural parts, but also comparable lightweight components from others Application and a corresponding manufacturing process.
  • DE 195 29 881 C1 proposes body parts from one hardenable spring steel - preferably in the warm state - deep drawing and the workpiece only in the finished state to spring steel hardness bring to. This procedure requires complex, heated deep-die tools and one in the press Integrated quenching system, which is cumbersome and in series operation with such a heterogeneous production with hot forming and heat treatment can expect a high failure rate.
  • the final structure of the rolled steel sets composed of ferrite, bainite and residual austenite, which increases mechanical strength up to 700 MPa with increased elongation values up to 14% and an increased elongation at break up to 25%.
  • Sheet thicknesses between 2.5 and 5 mm that can be produced are mentioned. With a silicon content of less than 0.5%, a After pickling, the surface of the hot-rolled is faultless Sheet metal can be ensured. applications exist e.g. in automobiles or in general in mechanical constructions for deep-drawn parts, folded parts, profiles or lightweight components.
  • the breaking strength of the steel increases with an increasing MLB content.
  • a minimum of 10% MLB is considered to be required to achieve the desired minimum breaking strength of 550 N / mm 2 .
  • the formability decreases with increasing MLB content.
  • An upper limit of about 35% of the MLB is required to obtain the desired maximum of 16% uniform expansion.
  • the volume content of MLB is preferably limited to approximately 15 to 25%, because such a proportion or area favors the formability and leads to elongation at break of the order of magnitude of at least 586 N / mm 2 .
  • Smaller amounts of high-temperature conversion products such as high bainite and pearlite may also be present, but these microcomponents must not adversely affect the desired combination of mechanical properties.
  • This target structure is not only easy to form, but also has high strength. Due to this combination of mechanical properties, the steel according to the invention can be used in difficult parts such as wheel disks, bumpers or in other lightweight construction applications where a high tear length is important.
  • the combination of a breaking strength of at least 550 N / mm 2 and a uniform elongation of at least 16% is considered to be a significant technical advance.
  • the invention is based, pull parts of the beginning mentioned type with a high part strength in a simple manner to be able to manufacture.
  • Hardened sheets generally lose with the increase in Strength, i.e. with increasing yield strength.
  • the measurable mechanical parameters such as uniform expansion or Elongation at break increases with increasing strength of the board material back.
  • This also applies to the recommended according to the invention fully bainitized spring steel.
  • this material exhibits unusually high forming properties "vertical anisotropy" and "solidification exponent" on the are completely unusual for conventionally hardened spring steel. Due to the high forming characteristics of the recommended bainitized spring steel it is possible that very high Process forces can be transferred without cracks. The occurring or process forces to be used can be about ten to Twenty times the process forces in deep drawing conventional Reach deep drawing steel. Because of this surprisingly high Forming characteristics of the bainitized recommended according to the invention Spring steel could interact with the abnormal Process forces the good thermoforming results are achieved.
  • Deep drawing or stretch drawing of sheet metal components is much higher Demands on the formability of a material than other forming processes such as Bending or punching.
  • the material is deep drawing or stretch drawing only much more difficult to master than bending because an increase in surface area with the pulls the output board is connected. Not every material, which can be bent well cold is also readily used as a drawing material suitable.
  • bainitizing spring steels are cold worked can (see e.g. a contribution from the trade journal "Draht", 3 (1992), pages 307-310). According to the applicant's level of knowledge are, however, only bending or punching as such types of forming Known materials, but not deep drawing or stretch drawing, where a much higher degree of stretching and compression and above all a multi-dimensional stretch or compression is required.
  • the steel When bainitizing, the steel must come from the austenitizing temperature and from the austenitized state very quickly - for example within a second - to a temperature that is well above the martensite start temperature is, e.g. on about 300 to 350 ° C, are cooled, including salt baths or lead baths can be used. The steel must then have a certain amount of time depending on the alloy of the steel - about 2 to 10 For minutes - be kept at this temperature until the austenite has completely transformed into a bainitic structure. Only then can the steel cool down to room temperature, what by leaving it standing or by forced cooling.
  • the yield strength of the hardened, bainitized spring steels is approximately in the range from 800 to 1800 N / mm 2 , preferably 900 to 1200 N / mm 2 ; the tensile strength is about 100 to 200 N / mm 2 higher.
  • the spring steel known from the applicant from the PT group of the PT group known as the spring steel with the designation PT120 has a tensile strength of 1200 N / mm 2 and a yield strength of 1000 N / mm 2 particularly recommended because, according to the applicant's knowledge, it has very good strength combined with very good forming properties in this group.
  • the DIN designations CK60 or C63 - or made of stainless steel - e.g. 67SiCr5 - can be used.
  • the use of stainless steel sheet is particularly recommended in the present case because the life expectancy of the less dent-sensitive body parts is higher than before and because rusting through with non-stainless steels is more likely than before with a long service life and smaller wall thicknesses.
  • the example recommended spring steel with the designation Ck60 (according to DIN) or 2 C 60 (according to Euronorm 83) has the following composition in% by weight: carbon 0.57 - 0.65%, silicon up to 0.40%, manganese 0.60 - 0.90%, phosphorus Max. 0.035%, sulfur Max. 0.030% and the rest iron.
  • the invention relates to a drawn part made of sheet steel, in particular for motor vehicle bodies, and a method for producing such drawn parts.
  • a spring steel sheet which has already been hardened in the initial state, namely bainitized - for example CK60 or C63 or 67SiCr5 - is used when pulling the body parts.
  • bainitized - for example CK60 or C63 or 67SiCr5 -
  • the drawn part according to the invention is therefore a pronounced lightweight component.
  • the spring steel sheet can be mechanically hardened in addition to the bainitization, for example by cold rolling or by heat treatment.
  • the yield strength of the plate material is approximately in the range from 800 to 1800 N / mm 2 and the tensile strength is above it.

Landscapes

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

Claims (16)

  1. Pièce emboutie en tôle d'acier, notamment pour des carrosseries de véhicules automobiles, caractérisée par l'utilisation d'une tôle d'acier pour ressorts déjà durcie à l'état initial, à savoir complètement bainitisée.
  2. Pièce emboutie selon la revendication 1, caractérisée par une tôle formée d'un acier portant la désignation Ck60 selon DIN ou 2 C 60 selon la norme Euronorm 83 ou formée d'aciers ayant la désignation C63 ou 67SiCr5 selon DIN.
  3. Pièce emboutie selon la revendication 1, caractérisée par une tôle formée d'un acier possédant une limite apparente d'élasticité à l'état initial ou en des emplacements non déformés comprise entre 800 et 1800 N/mm2 et de préférence entre 900 et 1200 N/mm2.
  4. Pièce emboutie selon la revendication 1, caractérisée par une tôle formée d'un acier possédant la composition suivante en % en poids: carbone 0,57-0,65 %, silicium jusqu'à 0,40 % manganèse 0,60-0,90 % phosphore maximum 0,035 %, soufre maximum 0,030 %,
    le reste étant formé de fer.
  5. Pièce emboutie selon la revendication 1, caractérisée par une tôle avec une épaisseur de tôle comprise entre 0,3 et 0,6 mm.
  6. Pièce emboutie selon la revendication 1, caractérisée en ce qu'une structuration fine sous la forme d'une structure en nid d'abeilles ou une structure gaufrée est superposée au moins aux zones moins fortement cintrées de la pièce emboutie.
  7. Procédé pour fabriquer des pièces embouties, selon lequel on introduit une platine en tôle dans une presse d'emboutissage et on l'étire et/ou on l'emboutit au moyen d'un outil de formage qui se ferme, notamment pour la fabrication de pièces embouties selon la revendication 1, caractérisé en ce qu'on utilise comme matériau pour la platine, une tôle en acier pour ressorts durcie, à savoir complètement bainitisée.
  8. Procédé selon la revendication 7, caractérisé en ce que pour la bainitisation à partir de la température d'austénitisation et à partir de l'état austénitique, moyennant l'utilisation de bains de sel ou de bains de plomb, on refroidit très rapidement l'acier - par exemple en l'espace d'une seconde - jusqu'à une température de bainitisation, qui est nettement supérieure à la témpérature de démarrage de la martensite, et on le maintient à cette température jusqu'à ce que l'austénite ait été complètement convertie en une structure bainitique, et on refroidit l'acier seulement ensuite jusqu'à la température ambiante.
  9. Procédé selon la revendication 8, caractérisé en ce qu'on refroidit l'acier jusqu'à une température de bainitisation comprise entre 300 et 350°C.
  10. Procédé selon la revendication 8, caractérisé en ce qu'on maintient l'acier, en fonction de la composition de l'alliage de l'acier, pendant 2 à 10 minutes à la température de bainitisation et qu'on réalise ainsi une bainitisation complète de l'acier.
  11. Procédé selon la revendication 8, caractérisé en ce qu'on effectue le refroidissement de l'acier bainitisé jusqu'à la température ambiante en le laissant reposer ou bien à l'aide d'un refroidissement forcé.
  12. Procédé selon la revendication 7, caractérisé en ce qu'en dehors de la bainitisation, on durcit la tôle d'acier pour ressorts, par exemple avant la subdivision en platines, au moyen d'un traitement thermique supplémentaire ou mécaniquement, par exemple par laminage à froid.
  13. Procédé selon la revendication 7, caractérisé en ce que pour des pièces de carrosserie moins ou même pas du tout exposées à la corrosion, on utilise comme matériau de la platine, de l'acier pour ressorts trempé possédant la désignation de matériau CK60 ou C63.
  14. Procédé selon la revendication 7, caractérisé en ce que pour des pièces de carrosserie exposées à la corrosion on utilise, comme matériau de la platine, un acier pour ressorts inoxydable trempé, par exemple de l'acier possédant la désignation de matériau 67SiCr5.
  15. Procédé selon la revendication 7, caractérisé en ce qu'on utilise comme matériau de la platine, un acier pour ressorts présentant une limite apparente d'élasticité dans la gamme comprise entre 800 et 1800 N/mm2 et notamment entre 800 et 1200 N/mm2 et une résistance à la traction supérieure.
  16. Procédé selon la revendication 7, caractérisé en ce qu'on utilise des platines ayant une épaisseur de tôle comprise entre 0,3 mm et 0,6 mm.
EP99907622A 1998-04-03 1999-03-11 Pieces embouties en tole d'acier a ressort, s'utilisant notamment comme element de construction legere ou element de carrosserie Expired - Lifetime EP1069962B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19815022 1998-04-03
DE19815022A DE19815022A1 (de) 1998-04-03 1998-04-03 Ziehteile aus Federstahlblech, insbesondere als Leichtbau- oder Karosserieteil
PCT/EP1999/001578 WO1999051376A1 (fr) 1998-04-03 1999-03-11 Pieces embouties en tole d'acier a ressort, s'utilisant notamment comme element de construction legere ou element de carrosserie

Publications (2)

Publication Number Publication Date
EP1069962A1 EP1069962A1 (fr) 2001-01-24
EP1069962B1 true EP1069962B1 (fr) 2002-05-15

Family

ID=7863522

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99907622A Expired - Lifetime EP1069962B1 (fr) 1998-04-03 1999-03-11 Pieces embouties en tole d'acier a ressort, s'utilisant notamment comme element de construction legere ou element de carrosserie

Country Status (5)

Country Link
US (1) US6364973B1 (fr)
EP (1) EP1069962B1 (fr)
DE (2) DE19815022A1 (fr)
ES (1) ES2177249T3 (fr)
WO (1) WO1999051376A1 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7585017B2 (en) 2005-05-10 2009-09-08 Noble Advanced Technologies, Inc. One-piece, tubular member with an integrated welded flange and associated method for producing
DE102005041741B4 (de) * 2005-09-02 2010-03-18 Daimler Ag Verfahren zum Herstellen eines pressgehärteten Bauteils
DE102006019567B3 (de) * 2006-04-27 2007-11-08 Daimlerchrysler Ag Verfahren zum Herstellen umgeformter Stahlbauteile
NL2002248C2 (en) * 2008-11-24 2010-05-26 Weweler Nv Hardening of flexible trailing arms.
DE102016001229A1 (de) * 2016-02-04 2017-08-10 GM Global Technology Operations LLC (n. d. Ges. d. Staates Delaware) Blechwerkstück
DE102018209847B4 (de) 2018-06-19 2020-01-02 Audi Ag Blechbauteil

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4033789A (en) 1976-03-19 1977-07-05 Jones & Laughlin Steel Corporation Method of producing a high strength steel having uniform elongation
DE2658335A1 (de) * 1976-12-23 1978-07-06 Uniplanung Gmbh & Co Kg Verfahren und ziehwerkzeug zum tiefziehen von blechformteilen, insbesondere von becken in spueltischabdeckungen aus edelstahl
GB2023668B (en) * 1978-04-28 1982-10-13 Neturen Co Ltd Steel for cold plastic working
US4609410A (en) * 1980-12-04 1986-09-02 United States Steel Corporation Method for producing high-strength deep-drawable dual-phase steel sheets
US4619714A (en) * 1984-08-06 1986-10-28 The Regents Of The University Of California Controlled rolling process for dual phase steels and application to rod, wire, sheet and other shapes
US5213634A (en) * 1991-04-08 1993-05-25 Deardo Anthony J Multiphase microalloyed steel and method thereof
FR2748033B1 (fr) 1996-04-26 1998-05-22 Lorraine Laminage Procede de realisation d'une bande de tole d'acier laminee a chaud a tres haute resistance utilisable pour la mise en forme et notamment pour l'emboutissage

Also Published As

Publication number Publication date
DE19815022A1 (de) 1999-10-21
EP1069962A1 (fr) 2001-01-24
US6364973B1 (en) 2002-04-02
WO1999051376A1 (fr) 1999-10-14
ES2177249T3 (es) 2002-12-01
DE59901460D1 (de) 2002-06-20

Similar Documents

Publication Publication Date Title
EP0946311B1 (fr) Procede pour produire une piece faconnee en tole par formage
DE60121233T2 (de) Hochfestes Kaltgewalztes Stahlblech mit hoch r-Wert, exzellenter Reckalterungseigenschaften und Alterungsbeständigkeit sowie Verfahren zur dessen Herstellung
DE60116477T2 (de) Warm-, kaltgewalzte und schmelz-galvanisierte stahlplatte mit exzellentem reckalterungsverhalten
DE102007008117B3 (de) Verfahren und Vorrichtung zum temperierten Umformen von warmgewalztem Stahlmaterial
EP2297367B1 (fr) Procédé de production d'une pièce moulée en acier à structure à prédominance ferritique-bainitique
DE60300835T2 (de) Kaltgewalztes Stahlblech mit ultrafeinem Korngefüge und Verfahren zu dessen Herstellung
DE10259230A1 (de) Verfahren zum Herstellen eines Stahlprodukts
EP1918403B1 (fr) Procédé de fabrication de produits plats en acier à partir d'un acier formant une structure marténsitique
EP1939308A1 (fr) Procédé de fabrication d'un composant par trempe de compression thermique et composant haute résistance présentant une amélioration de l'allongement de rupture
WO2013124283A1 (fr) Procédé de production de pièces moulées à haute résistance, en acier moulé austénitique à haute teneur en carbone et en manganèse, à propriétés trip/twip
DE10161465C1 (de) Verfahren zum Herstellen von Warmband
DE102004054444B3 (de) Verfahren zur Herstellung von Stahlbauteilen mit höchster Festigkeit und Plastizität
EP1069962B1 (fr) Pieces embouties en tole d'acier a ressort, s'utilisant notamment comme element de construction legere ou element de carrosserie
DE102018121709A1 (de) Verfahren zur wärmebehandlung von stahl
DE102008022401B4 (de) Verfahren zum Herstellen eines Stahlformteils mit einem überwiegend bainitischen Gefüge
DE2657435C2 (de) Verfahren zum Verbessern der physikalischen Eigenschaften eines hochfesten, niedriglegierten Kohlenstoff-Mangan-Stahls
DE102011121679B4 (de) Verfahren zur Herstellung von Bauteilen aus Leichtbaustahl
EP3585531B1 (fr) Procédé pour la fabrication d'une pièce par mise en forme ultérieure d'un contour préformé
DE102017110851B3 (de) Verfahren zum Erzeugen von Stahlverbundwerkstoffen
DE3702634A1 (de) Stahlstift fuer ein befestigungsmittel und verfahren zu dessen herstellung
DE102019219235B3 (de) Verfahren zur Herstellung eines warmumgeformten und pressgehärteten Stahlblechbauteils
DE102021131713A1 (de) Verfahren zur verbesserung der zähigkeit von presshärtendem stahl
DE112014004087B4 (de) Verfahren zur Herstellung eines hochfesten bzw. höchstfesten Formteils aus härtbarem Stahl
WO2020244974A1 (fr) Procédé de fabrication d'une pièce en tôle d'acier façonnée à chaud et trempée à la presse
DE102018133034A1 (de) Verfahren zur Herstellung eines Rohres und Rohrprodukt

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: 20000915

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR GB IT

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

17Q First examination report despatched

Effective date: 20010706

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB IT

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20020516

REF Corresponds to:

Ref document number: 59901460

Country of ref document: DE

Date of ref document: 20020620

ET Fr: translation filed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2177249

Country of ref document: ES

Kind code of ref document: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20030218

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

Ref country code: GB

Payment date: 20040303

Year of fee payment: 6

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

Ref country code: DE

Payment date: 20040305

Year of fee payment: 6

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

Ref country code: ES

Payment date: 20040322

Year of fee payment: 6

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

Ref country code: IT

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

Effective date: 20050311

Ref country code: GB

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

Effective date: 20050311

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

Ref country code: FR

Payment date: 20050311

Year of fee payment: 7

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

Ref country code: ES

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

Effective date: 20050312

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

Ref country code: DE

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

Effective date: 20051001

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20050311

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20050312

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20061130

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

Ref country code: FR

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

Effective date: 20060331