Interim temper process

Patent metadata

Field	Value
Publication number	US-11603586-B2
Application number	US-201916585079-A
Country	US
Kind code	B2
Filing date	Sep 27, 2019
Priority date	Sep 27, 2019
Publication date	Mar 14, 2023
Grant date	Mar 14, 2023

Abstract

A method for forming a structure using an interim temper process is provided. A metal material is partially-aged to a stable temper that does not require cold storage. The partially-aging step is completed at a supplier facility prior to the metal material being received by the manufacturer. Once received by the manufacturer, the partially-aged metal material is heated to a first temperature to perform retrogression. A structure is formed from the partially-aged metal material after performing the retrogression. The structure is shaped and inspected. The structure is then heated to a second temperature in an age oven to reach its final aged state. The final aged state may be close to, meet, or exceed a T6 temper.

First claim

What is claimed is:

1. A method for forming a structure, the method comprising:
solution heat-treating a metal material to a stable temper that does not require cold storage before retrogression to obtain a partially-aged metal material;
heating the partially-aged metal material to a first temperature to perform retrogression;
roll forming the structure from the partially-aged metal material after performing the retrogression, wherein the partially-aged metal material is not placed in cold storage before roll forming; and
heating the structure to a second temperature to reach a final aged state after roll forming, wherein the final aged state is a T6 temper.

2. The method of claim 1 , wherein solution heat-treating comprises:
forming the partially-aged metal material by heating the metal material to a temperature of between 170- and 190-degrees Fahrenheit for less than four hours.

3. The method of claim 1 , wherein solution heat-treating comprises:
forming the partially-aged metal material by naturally aging the metal material at room temperature for up to 40 hours to reach a desired Rockwell hardness.

4. The method of claim 1 wherein
the partially-aged metal material is received from a supplier facility.

5. The method of claim 1 , wherein the partially-aged metal material comprises a yield stress between 32 and 50 ksi prior to the retrogression, and wherein the partially-aged metal material comprises a yield stress between 32 and 45 ksi after the retrogression.

6. The method of claim 5 , wherein heating the partially-aged metal material to the first temperature to perform the retrogression comprises:
heating the partially-aged metal material to approximately 400-degrees Fahrenheit for two to five minutes.

7. The method of claim 5 , wherein the partially-aged metal material comprises a difference in ultimate tensile strength and tensile yield strength of between 25 and 30 ksi after the retrogression.

8. The method of claim 7 further comprising:
monitoring a state of aging during the retrogression; and
determining a cycle time for the retrogression based on the state of aging.

9. The method of claim 1 further comprising:
taper machining the partially-aged metal material, wherein the partially-aged metal material is not quenched after the taper machining or before the roll forming.

10. A method for forming a stringer for an aircraft, the method comprising:
receiving a partially-aged metal material from a supplier facility, wherein the partially-aged metal material has been solution heat-treated to a stable temper that does not require cold storage before retrogression to obtain the partially-aged metal material;
taper machining the partially-aged metal material;
performing retrogression on the partially-aged metal material by heating the partially-aged metal material to a first temperature;
roll forming the stringer from the partially-aged metal material after performing the retrogression; and
heating the stringer to a second temperature reach a final aged state after roll forming, wherein the final aged state is a T6 temper.

11. The method of claim 10 , wherein the partially-aged metal material is not placed in cold storage before the roll forming.

12. The method of claim 10 , wherein the partially-aged metal material comprises a yield stress between 32 and 50 ksi prior to the retrogression.

13. The method of claim 10 , wherein performing the retrogression comprises:
heating the partially-aged metal material to the first temperature of 400-degrees Fahrenheit for less than five minutes.

14. The method of claim 10 , wherein the partially-aged metal material is formed by heating a metal material to a temperature of 170- and 190-degrees Fahrenheit for less than four hours.

15. A manufacturing system comprising:
solution heat-treating a metal material to a stable temper that does not require cold storage before retrogression to obtain a partially-aged metal material;
a heating system configured to heat the partially-aged metal material to a first temperature to perform retrogression;
a roll forming system configured to roll form a structure from the partially-aged metal material after performing the retrogression, wherein the partially-aged metal material is not placed in cold storage before the roll forming; and
an aging oven configured to heat the structure to a second temperature to reach a final aged state for the structure after roll forming, wherein the final aged state is a T6 temper.

16. The manufacturing system of claim 15 further comprising:
a partial-aging system for the metal material, wherein the partial-aging system is configured to solution heat treat the metal material and heat the metal material to form the partially-aged metal material.

17. The manufacturing system of claim 16 , wherein the partially-aged metal material comprises a yield stress between 32 and 50 ksi prior to the retrogression.

18. The manufacturing system of claim 17 , wherein the first temperature is approximately 400-degrees Fahrenheit and the heating system is configured to heat the partially-aged metal material at the first temperature for two to five minutes to perform the retrogression.

19. The manufacturing system of claim 18 further comprising:
a monitoring system configured to monitor a state of aging during the retrogression; and
a controller configured to determine a cycle time for the retrogression based on the state of aging.

20. The method of claim 1 , wherein heating the structure to the second temperature to reach the final aged state after roll forming, comprises:
heating the structure to the second temperature between 200- and 300-degrees Fahrenheit for less than eighteen hours.

Assignees

• Boeing Co

Inventors

• Weber Gary Robert
• Campbell Clinton J

Classifications

• C22F1/04 Primary

  of aluminium or alloys based thereon · CPC title

• C22F1/053

  of alloys with zinc as the next major constituent · CPC title

• C21D9/00

  Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor · CPC title

• C22F1/002 Primary

  by rapid cooling or quenching; cooling agents used therefor · CPC title

• C22C21/10

  with zinc as the next major constituent · CPC title