(19)
(11) EP 2 003 219 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
published in accordance with Art. 153(4) EPC

(15) Correction information:
Corrected version no 2 (W2 A1)

(48) Corrigendum issued on:
19.08.2009 Bulletin 2009/34

(43) Date of publication:
17.12.2008 Bulletin 2008/51

(21) Application number: 07739465.8

(22) Date of filing: 23.03.2007
(51) International Patent Classification (IPC): 
C22C 21/02(2006.01)
C22C 21/06(2006.01)
C22F 1/00(2006.01)
 B21K 7/12(2006.01)
C22F 1/05(2006.01)
(86) International application number:
PCT/JP2007/056024
(87) International publication number:
WO 2007/114078 (11.10.2007 Gazette 2007/41)
(84) Designated Contracting States:
DE FR GB

(30) Priority: 31.03.2006 JP 2006098642
08.12.2006 JP 2006332194

(71) Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO
Kobe-shi, Hyogo 651-8585 (JP)

(72) Inventors:
  • NAKAI, Manabu c/o Kobe Corporate Research Laboratories in Kobe Steel, Ltd.
    Kobe-shi, Hyogo 651-2271 (JP)
  • INAGAKI, Yoshiya c/o Daian Plant in Kobe Steel, Ltd
    Inabe-shi, Mie 511-0200 (JP)
  • FUKUDA, Atsumi c/o Daian Plant in Kobe Steel, Ltd.
    Inabe-shi, Mie 511-0200 (JP)

(74) Representative: Müller-Boré & Partner Patentanwälte 
Grafinger Strasse 2
81671 München
81671 München (DE)

   


(54) ALUMINUM ALLOY FORGING MEMBER AND PROCESS FOR PRODUCING THE SAME


(57) The present invention provides an aluminum alloy forging material having enhanced strength, toughness, and corrosion resistance, and a method of producing the material. An aluminum alloy forging material 1 produced with specified components under specified conditions has an arm portion 2 including a relatively narrow and thick peripheral rib 3 and a thin and relatively wide central web 4 having a thickness of 10 mm or less and having a substantially H-shaped sectional form. In a width-direction section of a maximum stress producing site of the rib 3a, the density of crystals observed in the structure of a sectional portion 7 where the maximum stress is produced, the spacing of grain boundary precipitates and the size and density of dispersed particles observed in the structure of a sectional portion 8 including a parting line, the recrystallization ratio observed in each of the sectional portions 7 and 8 of the rib, and the recrystallization ratio observed in a sectional portion 9 of the web 4a adjacent to the sectional structure of the rib 3a in the width direction are defined for enhancing the strength, toughness, and corrosion resistance of the aluminum alloy forging material.