Global Patent Index - EP 2045360 A1

EP 2045360 A1 20090408 - Method for manufacturing a steel part by hot forming and steel part manufactured by hot forming

Title (en)

Method for manufacturing a steel part by hot forming and steel part manufactured by hot forming

Title (de)

Verfahren zum Herstellen eines Stahlbauteils durch Warmformen und durch Warmformen hergestelltes Stahlbauteil

Title (fr)

Procédé de fabrication d'un composant en acier par façonnage à chaud et composant en acier fabriqué par façonnage à chaud

Publication

EP 2045360 A1 20090408 (DE)

Application

EP 07117719 A 20071002

Priority

EP 07117719 A 20071002

Abstract (en)

A low-alloy, sheet steel which can be hardened, is coated with metal containing at least 85 wt% aluminum and up to 15 wt% Si. A zinc coating is then added, containing at least 90 wt% Zn. The material is heated to at least 750[deg] C prior to thermal deformation. The flat product is then thermo-formed to make the steel component. To produce the hardened structure, it is cooled at a sufficiently rapid rate. The hot deformation temperature is preferably 850-900[deg] C. The aluminum coating is added by hot dip aluminization. It contains 5-12 wt% silicon. The zinc is coated onto the aluminum layer electrolytically. It contains at least 99 wt% Zn. It is alternatively coated by physical vapor deposition. In the zinc coating, one or more of Al, Mg and Si are contained. Before zinc coating, the aluminum-coated steel is given a rolled finish. It is pickled before zinc coating. Both coatings take pace continuously, in successive processes. Alternatively, successive batch processes are used. Hot deformation takes place in one or more stages. This is optionally preceded by cold deformation. Before heating, the aluminum coating has a thickness of 5-25 mu m. Before heating, a 2-5 mu m thick alloying boundary layer containing Al, Si and Fe is provided between the steel and the aluminum. The total thickness of the coating on the steel before heating, is 7-35 mu m. The base layer coating on the steel is predominantly aluminum, containing Fe, Zn and Si. This is coated with a layer of metal predominantly comprising zinc, which contains Al, Si and Fe. The base layer contains at least: 30 wt% Al, 20 wt% Fe and 3 wt% Si. The outer covering layer contains at least: 60 wt% Zn, 5 wt% Al. It also includes up to: 10 wt% Fe and 10 wt% Si. The base layer thickness is 15-25 mu m. The covering layer thickness is 3-10 mu m. The sheet steel product is produced from manganese-boron steel. An independent claim IS INCLUDED FOR the corresponding steel component.

Abstract (de)

Die vorliegende Erfindung betrifft ein Verfahren zum Herstellen eines mit einem metallischen, vor Korrosion schützenden Überzug versehenen Stahlbauteils, umfassend folgende Arbeitsschritte: - Beschichten eines aus einem niedrig legierten Vergütungsstahl erzeugten Stahlflachprodukts mit einem Al-Überzug, der mindestens 85 Gew.-% Al und optional bis zu 15 Gew.-% Si enthält; - Beschichten des mit dem Al-Überzug versehenen Stahlflachproduktes mit einem Zn-Überzug, der mindestens 90 Gew.-% Zn enthält, - Erwärmen des Stahlflachproduktes auf eine mindestens 750 °C betragende Warmformtemperatur, - Warmformen des erwärmten Stahlbauteils aus dem Stahlflachprodukt, und - zur Ausbildung von Vergütungs- oder Härtegefüge ausreichend schnell erfolgendes Abkühlen des warmgeformten Stahlbauteils.

IPC 8 full level

C23C 28/02 (2006.01); C21D 7/13 (2006.01)

CPC (source: EP US)

C21D 7/02 (2013.01 - EP US); C21D 8/0205 (2013.01 - EP US); C21D 8/0278 (2013.01 - EP US); C21D 9/48 (2013.01 - EP US); C23C 2/02 (2013.01 - EP US); C23C 2/0224 (2022.08 - EP US); C23C 2/024 (2022.08 - EP US); C23C 2/06 (2013.01 - EP US); C23C 2/12 (2013.01 - EP US)

Citation (search report)

  • [XA] WO 2005009642 A1 20050203 - DAIMLER CHRYSLER AG [DE], et al
  • [A] EP 1143029 A1 20011010 - USINOR [FR]
  • [A] DE 10246614 A1 20040415 - BENTELER AUTOMOBILTECHNIK GMBH [DE]
  • [A] WO 2006045570 A1 20060504 - THYSSENKRUPP STEEL AG [DE], et al
  • [A] EP 1767670 A1 20070328 - THYSSENKRUPP STEEL AG [DE]
  • [A] JP S57200548 A 19821208 - MITSUBISHI HEAVY IND LTD
  • [A] LENZE F-J ET AL: "Herstellung von Karosseriebauteilen aus warmumgeformten hŸchfesten Stahlwerkstoffe", EFB TAGUNGSBAND, EUROPAEISCHE FORSCHUNGSGESELLSCHAFT FUER BLECHVERARBEITUNG, DE, vol. 25, 1 January 2005 (2005-01-01), pages 53 - 61, XP009098694
  • [A] BABBIT M: "SOME HIGHLIGHTS ON NEW STEEL PRODUCTS FOR AUTOMOTIVE USE", STEEL RESEARCH INTERNATIONAL, VERLAG STAHLEISEN GMBH., DUSSELDORF, DE, vol. 77, no. 9/10, 1 January 2006 (2006-01-01), pages 620 - 626, XP001503675, ISSN: 1611-3683

Designated contracting state (EPC)

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

Designated extension state (EPC)

AL BA HR MK RS

DOCDB simple family (publication)

EP 2045360 A1 20090408; EP 2045360 B1 20111130; AT E535631 T1 20111215; US 2010294400 A1 20101125; WO 2009047183 A1 20090416

DOCDB simple family (application)

EP 07117719 A 20071002; AT 07117719 T 20071002; EP 2008063139 W 20081001; US 68128608 A 20081001