| (19) |
 |
|
(11) |
EP 1 176 222 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
06.03.2002 Bulletin 2002/10 |
| (43) |
Date of publication A2: |
|
30.01.2002 Bulletin 2002/05 |
| (22) |
Date of filing: 27.06.2001 |
|
| (51) |
International Patent Classification (IPC)7: C22F 1/10 |
|
| (84) |
Designated Contracting States: |
|
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
Designated Extension States: |
|
AL LT LV MK RO SI |
| (30) |
Priority: |
30.06.2000 US 215601
03.04.2001 US 825128
|
| (71) |
Applicant: GENERAL ELECTRIC COMPANY |
|
Schenectady, NY 12345 (US) |
|
| (72) |
Inventors: |
|
- Rowe, Raymond Grant
Schenectady, New York 12309 (US)
- Mika, David Peter
Clifton Park, New York 12065 (US)
- Majorell, Arne Ronald
Danby, Vermont 05739 (US)
|
| (74) |
Representative: Pedder, James Cuthbert et al |
|
GE London Patent Operation, Essex House, 12/13 Essex Street
London WC2R 3AA
London WC2R 3AA (GB) |
|
| |
|
| (54) |
Heat treatment of nickel-base superalloy die inserts |
(57) A rigid die insert for forming and shaping a working material comprises a nickel-base
superalloy, preferably Rene 95. A plurality of gamma prime particles are uniformly
distributed throughout the rigid die insert, which has a Rockwell hardness Rc of between
about 48 and about 52. The invention also includes a method of treating a rigid die
insert comprising a nickel-base superalloy to reduce crack propagation and raise yield
stress. The method comprises the steps of: providing the rigid die insert; dissolving
larger gamma-prime particles in the rigid die insert; and growing additional gamma-prime
particles of smaller particle size in the rigid die insert, whereby the particle size
of each of the plurality of gamma-prime particles is refined, thereby reducing crack
propagation and raising the yield stress of the rigid die insert. A method of refining
the particle size of gamma-prime particles in a Rene 95 superalloy is also disclosed.