(19)
(11) EP 1 533 391 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
published in accordance with Art. 158(3) EPC

(15) Correction information:
Corrected version no 1 (W1 A1)

(48) Corrigendum issued on:
26.04.2006 Bulletin 2006/17

(43) Date of publication:
25.05.2005 Bulletin 2005/21

(21) Application number: 03736120.1

(22) Date of filing: 09.06.2003
(51) International Patent Classification (IPC): 
C22C 14/00(1974.07)
C23G 1/12(1968.09)
(86) International application number:
PCT/JP2003/007297
(87) International publication number:
WO 2003/104506 (18.12.2003 Gazette 2003/51)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR

(30) Priority: 11.06.2002 JP 2002169441

(71) Applicant: SUMITOMO METAL INDUSTRIES, LTD.
Osaka-shi, Osaka 541-0041 (JP)

(72) Inventor:
  • TAKAHASHI, Wataru, Sumitomo Metal Industries, Ltd.
    Osaka-shi, Osaka 541-0041 (JP)

(74) Representative: Simons, Amanda Louise 
J.A. Kemp & Co., 14 South Square, Gray's Inn
London WC1R 5JJ
London WC1R 5JJ (GB)


(56) References cited: : 
   
       


    (54) BETA TYPE TITANIUM ALLOY AND PROCESS FOR PRODUCING THE SAME


    (57) The present invention provides a β type titanium alloy characterized by consisting of, by mass %, V: 15 to 25%, Al: 2.5 to 5%, Sn: 0.5 to 4%, O (Oxygen): not more than 0.20%, H: not more than 0.03%, Fe: not more than 0.40%, C: not more than 0.05% and N: not more than 0.02%, and the balance Ti and impurities.
    The present invention also provides a method of manufacturing a β type titanium alloy characterized by comprising the following steps (a) to (c):

    (a) Preparing a β type titanium alloy consisting of, by mass %, V: 15 to 25%, Al: 2.5 to 5%, Sn: 0.5 to 4%, O (Oxygen): not more than 0.20%, H: not more than 0.03%, Fe: not more than 0.40%, C: not more than 0.05% and N: not more than 0.02%, and the balance Ti and impurities.

    (b) Pickling the β type titanium alloy in an aqueous solution including 3 to 40 mass % of HF, and

    (c) Further pickling the β type titanium alloy in an aqueous solution including 3 to 6 mass % of HF and 5 to 20 mass % of HNO3.