Thermo-mechanical processing of nickel-base alloys

• US 8,652,400 B2
• Filed: 06/01/2011
• Issued: 02/18/2014
• Est. Priority Date: 06/01/2011
• Status: Active Grant

• Current Assignee: ATI Properties LLC (CNH Industrial N.V.)
• Original Assignee: ATI Properties Incorporated (Allegheny Technologies Incorporated)
• Inventors: Forbes Jones, Robin M., Rock, Christopher D.
• Primary Examiner(s): Kastler, Scott
• Assistant Examiner(s): Aboagye, Michael
• Application Number:
  US13/150,494
• Publication Number:
  US 20120308428A1
• Time in Patent Office: 993 Days
• Field of Search: 420/441, 420/442, 420/443, 420/447, 420/452, 420/457, 420/459, 148/676, 148/677, 148/675, 148/649, 723/62
• US Class Current: 420/442
• CPC Class Codes: B05D 3/007 After-treatment
• CPC Class Codes: B05D 7/52 Two layers
• CPC Class Codes: B21D 22/022 by heating the blank or stamping associated with heat treatment C21D takes precedence
• CPC Class Codes: B21J 1/06 Heating or cooling methods or arrangements specially adapted for performing forging or pressing operations B21J5/063 takes precedence
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/222 metal compounds not provided for in groups C08G18/225 - C08G18/26
• CPC Class Codes: C08G 18/3206 aliphatic
• CPC Class Codes: C08G 18/4841 containing oxyethylene end groups
• CPC Class Codes: C08G 18/7657 containing two or more aromatic rings
• CPC Class Codes: C08G 18/7671 containing only one alkylene bisphenyl group
• CPC Class Codes: C08J 2375/04 Polyurethanes
• CPC Class Codes: C08J 2375/08 from polyethers
• CPC Class Codes: C08J 9/32 from compositions containing microballoons, e.g. syntactic foams
• CPC Class Codes: C08K 7/28 Glass
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: C09D 175/08 from polyethers
• CPC Class Codes: C22C 19/05 with chromium
• CPC Class Codes: C22C 19/058 without Mo and W
• CPC Class Codes: C22F 1/10 of nickel or cobalt or alloys based thereon
• CPC Class Codes: F16L 59/14 Arrangements for the insulation of pipes or pipe systems F16L59/02 - F16L59/12 take precedence

Abstract

A thermo-mechanical treatment process is disclosed. A nickel-base alloy workpiece is heated in a first heating step to a temperature greater than the M₂₃C₆ carbide solvus temperature of the nickel-base alloy. The nickel-base alloy workpiece is worked in a first working step to a reduction in area of 20% to 70%. The nickel-base alloy workpiece is at a temperature greater than the M₂₃C₆ carbide solvus temperature when the first working step begins. The nickel-base alloy workpiece is heated in a second working step to a temperature greater than 1700° F. (926° C.) and less than the M₂₃C₆ carbide solvus temperature of the nickel-base alloy. The nickel-base alloy workpiece is not permitted to cool to ambient temperature between completion of the first working step and the beginning of the second heating step. The nickel-base alloy workpiece is worked to a second reduction in area of 20% to 70%. The nickel-base alloy workpiece is at a temperature greater than 1700° F. (926° C.) and less than the M₂₃C₆ carbide solvus temperature of the nickel-base alloy when the second working step begins.

Claims

1. A process comprising:

a first heating step comprising heating a nickel-base alloy workpiece to a temperature in the range of 2000°

F. to 2125°

F.;

a first forging step comprising rotary forging the heated nickel-base alloy workpiece to a reduction in area of 30% to 70%, wherein the nickel-base alloy workpiece is at a temperature in the range of 2000°

F. to 2125°

F. when the first forging step begins;

a second heating step comprising heating the rotary-forged nickel-base alloy workpiece to a temperature in the range of 1750°

F. to 1925°

F., wherein the rotary-forged nickel-base alloy workpiece is maintained at elevated temperature and not permitted to cool to ambient temperature between completion of the first forging step and beginning of the second heating step; and

a second forging step comprising rotary forging the heated nickel-base alloy workpiece to a reduction in area of 20% to 70%, wherein the nickel-base alloy workpiece is at a temperature in the range of 1750°

F. to 1925°

F. when the second forging step begins;

wherein the nickel-base alloy workpiece comprises, by weight, up to 0.05% carbon, 27.0% to 31.0% chromium, up to 0.5% copper, 7.0% to 11.0% iron, up to 0.5% manganese, up to 0.015% sulfur, up to 0.5% silicon, at least 58% nickel, and incidental impurities.

2. The process of claim 1, wherein the first heating step comprises heating the nickel-base alloy workpiece in a furnace operating at 2000°

F. to 2125°

F. for at least 6.0 hours time-at-temperature.

3. The process of claim 1, wherein the second heating step comprises heating the rotary-forged nickel-base alloy workpiece in a furnace operating at 1750°

F. to 1925°

F. for greater than 2.0 hours furnace time.

4. The process of claim 1, wherein the second heating step comprises heating the rotary-forged nickel-base alloy workpiece in a furnace operating at 1750°

F. to 1925°

F. for 3.0 hours to 10.0 hours furnace time.

5. The process of claim 1, wherein the second heating step comprises heating the rotary-forged nickel-base alloy workpiece in a furnace operating at 1750°

F. to 1925°

F. for 4.0 hours to 8.0 hours furnace time.

6. The process of claim 1, further comprising:

vacuum induction melting feed materials to form a nickel-base alloy ingot;

remelting the nickel-base alloy ingot to form a refined nickel-base alloy ingot, wherein the remelting comprises at least one remelting operation selected from the group consisting of vacuum arc remelting and electroslag remelting; and

press forging the refined nickel-base alloy ingot to form the nickel-base alloy workpiece.

7. The process of claim 1, further comprising, after the two heating steps and the two forging steps:

heating the nickel-base alloy workpiece at a temperature of at least 1800°

F., but no greater than a M₂₃C₆ carbide solvus temperature of the nickel-base alloy, for at least 3.0 hours time-at-temperature; and

water quenching the workpiece.

8. The process of claim 1, further comprising, after the two heating steps and the two forging steps:

aging the nickel-base workpiece at a temperature of 1300°

F. to 1400°

F. for at least 3.0 hours time-at-temperature; and

air cooling the workpiece.

9. A process comprising:

a first heating step comprising heating a nickel-base alloy workpiece to a temperature greater than a M₂₃C₆ carbide solvus temperature of the nickel-base alloy;

a first working step comprising working the heated nickel-base alloy workpiece to a reduction in area of 20% to 70%, wherein the nickel-base alloy workpiece is at a temperature greater than a M₂₃C₆ carbide solvus temperature when the first working step begins;

a second heating step comprising heating the worked nickel-base alloy workpiece to a temperature greater than 1700°

F. and less than the M₂₃C₆ carbide solvus temperature of the nickel-base alloy, wherein the as-worked nickel-base alloy workpiece is maintained at elevated temperature and not permitted to cool to ambient temperature between completion of the first working step and beginning of the second heating step; and

a second working step comprising working the heated nickel-base alloy workpiece to a second reduction in area of 20% to 70%, wherein the nickel-base alloy workpiece is at a temperature greater than 1700°

F. and less than the M₂₃C₆ carbide solvus temperature of the nickel-base alloy when the second working step begins;

wherein the nickel-base alloy workpiece comprises, by weight, up to 0.05% carbon, 27.0% to 31.0% chromium, up to 0.5% copper, 7.0% to 11.0% iron, up to 0.5% manganese, up to 0.015% sulfur, up to 0.5% silicon, at least 58% nickel, and incidental impurities.

10. The process of claim 9, wherein the nickel-base alloy workpiece comprises, by weight, up to 0.05% carbon;

28.0% to 30.0% chromium;

up to 0.25% copper;

8.0% to 10.0% iron;

up to 0.25% manganese;

up to 0.010% sulfur;

up to 0.25% silicon;

at least 58% nickel; and

incidental impurities.

11. The process of claim 9, wherein the first working step and the second working step independently comprise at least one operation selected from the group consisting of flat rolling, ring rolling, roll forming, press forging, extruding, and rotary forging.

12. The process of claim 9, wherein the first working step and the second working step comprise rotary forging.

13. The process of claim 9, wherein the first heating step comprises heating the nickel-base alloy workpiece in a furnace operating at 2000°

F. to 2125°

F. for at least 3.0 hours time-at-temperature.

14. The process of claim 9, wherein second heating step comprises heating the nickel-base alloy workpiece in a furnace operating at 1750°

F. to 1925°

F. for greater than 2.0 hours furnace time.

15. The process of claim 9, wherein the second heating step comprises heating the nickel-base alloy workpiece in a furnace operating at 1750°

F. to 1925°

F. for 3.0 hours to 10.0 hours furnace time.

16. The process of claim 9, wherein the second heating step comprises heating the rotary-forged nickel-base alloy workpiece in a furnace operating at 1750°

F. to 1925°

F. for 4.0 hours to 8.0 hours furnace time.

17. The process of claim 9, further comprising:

vacuum induction melting feed materials to form a nickel-base alloy ingot;

remelting the nickel-base alloy ingot to form a refined nickel-base alloy ingot, wherein the remelting comprises at least one remelting operation selected from the group consisting of vacuum arc remelting and electroslag remelting; and

press forging the refined nickel-base alloy ingot to form the nickel-base alloy workpiece.

18. The process of claim 9, further comprising, after the two heating steps and the two working steps:

heating the nickel-base alloy workpiece at a temperature of at least 1800°

F., but no greater than a M₂₃C₆ carbide solvus temperature of the nickel-base alloy, for at least 3.0 hours time-at-temperature; and

water quenching the workpiece.

19. The process of claim 9, further comprising, after the two heating steps and the two forging steps:

aging the nickel-base alloy workpiece at a temperature of 1300°

F. to 1400°

F. for at least 3.0 hours time-at-temperature; and

air cooling the workpiece to ambient temperature.