Granted Patent B2

US 10,094,013 · App. 14/972,972 · Granted Oct 9, 2018

Abstract

Claims (28)

1. A method for heat-treating a titanium alloy, the method comprising the steps of:

recrystallization annealing the titanium alloy, wherein recrystallization annealing comprises heating the titanium alloy to a temperature 30° F. to 200° F. below beta transus of the titanium alloy for a length of time in a range of 1 hour to 6 hours followed by slow cooling the titanium alloy after to 1200° F. to 1500° F. at a rate of 50° F. to 500° F. per hour; and

beta annealing the titanium alloy following completion of the recrystallization annealing steps including heating the titanium alloy to a temperature in a range of 10° to 100° F. above the beta transus of the titanium alloy.

2. The method of claim 1 , wherein the beta annealing comprises holding the temperature above beta transus for 30 minutes per inch of thickness of the titanium alloy.

3. The method of claim 1 , wherein the beta annealing further comprises holding the temperature in the range of 10° to 100° F. above beta transus for 15 minutes to 5 hours.

4. The method of claim 1 , wherein beta transus of the titanium alloy is a temperature between 1800° F. and 1850° F.

5. The method of claim 1 , further comprising forging of the titanium alloy prior to the recrystallization annealing step.

6. The method of claim 1 , wherein the titanium alloy is Ti-6Al-4V.

7. The method of claim 1 , wherein the step of slow cooling the titanium alloy comprises furnace cooling the titanium alloy.

8. The method of claim 1 , further comprising a step of gradually heating then holding the titanium alloy at a temperature 30° F. to 200° F. below beta transus of the titanium alloy following the slow cooling of the recrystallization annealing step and immediately preceding the step of beta annealing.

9. The method of claim 8 , further comprising the steps of cooling the titanium alloy to a stabilization temperature between 1200° F. to 1450° F. for one or more hours following the beta annealing step and then cooling the titanium alloy to room temperature.

10. A method for heat-treating a titanium alloy, wherein the titanium alloy is Ti-6Al-4V, the method comprising the steps of:

recrystallization annealing the titanium alloy by heating the titanium alloy to a temperature in a range between 30° F. to 200° F. below beta transus of the titanium alloy for 1 hour to 6 hours and then furnace cooling of the titanium alloy to 1200° F. to 1500° F. at a rate of 50° F. to 500° F. per hour; and

beta annealing the titanium alloy following the furnace cooling step, wherein the beta annealing comprises heating the titanium alloy to a temperature in the range of 10° to 100° F. above beta transus of the titanium alloy for 15 minutes to 5 hours.

11. The method of claim 10 , wherein the beta annealing further comprises holding the temperature above beta transus for 30 minutes per inch of thickness of the titanium alloy.

12. The method of claim 10 , wherein beta transus of the titanium alloy is a temperature between 1800° F. and 1850° F.

13. The method of claim 10 , further comprising steps of forging of the titanium alloy prior to the recrystallization annealing step.

14. The method of claim 10 , further comprising a step of heating then holding the titanium alloy at a stabilization temperature of between 1200° F. to 1450° F. following the step of furnace cooling and immediately preceding the step of beta annealing.

15. The method of claim 10 , further comprising the steps of cooling the titanium alloy to a stabilization temperature between 1200° F. to 1450° F. for one or more hours following the beta annealing step and then cooling the titanium alloy to room temperature.

16. The method of claim 10 , wherein the recrystallization annealing includes holding the titanium alloy at the temperature in the range of 30° F. to 200° F. below beta transus of the titanium alloy for a length of time in a range of 1 hour to 4 hours.

17. A method for heat-treating a titanium alloy, wherein the titanium alloy is Ti-6Al-4V, the method comprising the steps of:

forging of the titanium alloy such that localized, highly deformed grains are formed in the titanium alloy;

recrystallization annealing the titanium alloy by heating and holding the titanium alloy at a temperature in a range between 30° F. to 200° F. below beta transus of the titanium alloy for a length of time in a range of 1 to 4 hours following the forging step, then furnace cooling the titanium alloy to 1200° F. to 1500° F. at a rate of 50° F. to 500° F. per hour, wherein beta transus of the titanium alloy is a temperature between 1800° F. and 1850° F., wherein the recrystallization annealing results in the highly deformed grains forming fine and uniform transformed beta grains throughout the titanium alloy; and

beta annealing the titanium alloy following the furnace cooling, wherein the beta annealing comprises:

reheating then holding the titanium alloy at the temperature in the range between 30° F. to 200° F. below beta transus of the titanium alloy, and

heating then holding the titanium alloy at a temperature above beta transus of the titanium alloy for an amount of time between 15 minutes to 5 hours.

18. The method of claim 17 , further comprising the steps of cooling the titanium alloy to a stabilization temperature between 1200° F. to 1450° F. for one or more hours following the beta annealing step and then cooling the titanium alloy to room temperature.

19. The method of claim 17 , wherein the beta annealing further comprises holding the temperature in a range of 10° to 100° F. above the beta transus for 30 minutes per inch of thickness of the titanium alloy.

Assignments (15)