EP 2045360 B1 20111130 - 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
Application
Priority
EP 07117719 A 20071002
Abstract (en)
[origin: EP2045360A1] 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.
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)
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
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