(19)

(11)

EP 2 533 917 A1

(12)

(43) Date of publication: 19.12.2012 Bulletin 2012/51 (21) Application number: 11742530.6 (22) Date of filing: 09.02.2011

(51) International Patent Classification (IPC):  B21C 25/02(2006.01) B21C 25/00(2006.01) B21C 25/04(2006.01) C23C 4/18(2006.01) (86) International application number: PCT/NO2011/000050 (87) International publication number: WO 2011/099868 (18.08.2011 Gazette 2011/33)

(84) Designated Contracting States: 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 (30) Priority: 12.02.2010 NO 20100218 (71) Applicant: Norsk Hydro ASA 0240 Olso (NO)	(72) Inventors: PASQUALON, Marco N-0268 Oslo (NO) BRÅTEN, Morten N-0372 Oslo (NO) DICKSON, Richard Farral Michigan 49461 (NO) (74) Representative: Hofseth, Svein  Patent and Trademark Department Hydro Aluminium AS 0240 Oslo 0240 Oslo (NO)