Claims
- 1. A method of producing titanium alloy parts having good heat resistance, comprising subjecting a titanium alloy composition consisting essentially of, by weight %, Al: 5.0-7.0%, Sn: 3.0-5.0%, Zr: 2.5-6.0%, Mo: 2.0-4.0%, Si: 0.05-0.80%, C: 0.001-0.200%, O: 0.05-0.20%, and the balance of Ti and inevitable impurities to the following sequential treatment steps:(1) a heat treatment step in β-region; (2) a rapid cooling step after the heat treatment in step (1) at a cooling rate higher than that of air-cooling to a temperature of 700° C. or lower; (3) a slow cooling step from a temperature of 700° C. or lower at a cooling rate of air cooling or lower; (4) a hot processing step in α+β region carried out at a temperature of β-transformation point or lower at a forging ratio of 3 or higher; (5) a solid solution treatment at a temperature of β-transformation point±30° C; and (6) an aging treatment at a temperature of 570-650° C.
- 2. A method of producing titanium alloy parts having good heat resistance according to claim 1, wherein the titanium alloy further consist essentially of at least one of Nb and Ta in a combined total of 0.3-2.0%.
- 3. A method of producing titanium alloy parts having good heat resistance, comprising subjecting a titanium alloy composition consisting essentially of, by weight %, Al: 5.0-7.0%, Sn: 3.0-5.0%, Zr: 2.5-6.0%, Mo: 2.0-4.0%, Si: 0.05-0.80%, C: 0.001-0.200%, O: 0.05-0.20%, and the balance of Ti and inevitable impurities to the following sequential treatment steps:(1) a heat treatment step in β-region; (2) a quenching step after the heat treatment in step (1) by water quenching; (3) an annealing step to remove distortion in the material; (4) a hot processing step in α+β region carried out at a temperature of β-transformation point or lower at a forging ratio of 3 or higher; (5) a solid solution treatment at a temperature of β-transformation point±30° C.; and (6) an aging treatment at a temperature of 570-650° C.
- 4. A method of producing titanium alloy parts having good heat resistance according to claim 3, wherein the titanium alloy further consist essentially of at least one of Nb and Ta in a combined total of 0.3-2.0%.
- 5. A method of producing titanium alloy parts having good heat resistance according to claim 1, wherein the heat treatment in step (1) is conducted in a range of β-transformation point+(10-80)° C.
- 6. A method of producing titanium alloy parts having good heat resistance according to claim 1, wherein the hot processing in step (4) is conducted in a range of β-transformation point−(30-150)° C.
- 7. A method of producing titanium alloy parts having good heat resistance according to claim 3, wherein the heat treatment in step (1) is conducted in a range of β-transformation point+(10-80)° C.
- 8. A method of producing titanium alloy parts having good heat resistance according to claim 3, wherein the hot processing in step (4) is conducted in a range of β-transformation point−(30-150)° C.
Priority Claims (1)
Number |
Date |
Country |
Kind |
8-349648 |
Dec 1996 |
JP |
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. Ser. No. 08/996,198, filed Dec. 22, 1997, now U.S. Pat. No. 5,922,274.
US Referenced Citations (8)