Welding superalloy articles

• US 6,333,484 B1
• Filed: 03/17/2000
• Issued: 12/25/2001
• Est. Priority Date: 03/17/2000
• Status: Expired due to Term

• Current Assignee: Chromalloy Gas Turbine LLC (Blue Jay Acquisition Corp.)
• Original Assignee: Chromalloy Gas Turbine Corporation (Blue Jay Acquisition Corp.)
• Inventors: Foster, Michael, Updegrove, Kevin
• Primary Examiner(s): Heinrich, Samuel M.
• Application Number:
  US09/527,362
• Time in Patent Office: 648 Days
• Field of Search: 219/121.63, 219/121.64, 219/121.85, 219/76.1, 228/222, 228/231, 228/232, 228/233.2, 228/262.3
• US Class Current: 219/121.64
• CPC Class Codes: B23K 20/002 specially adapted for particular articles or work B23K20/129 takes precedence
• CPC Class Codes: B23K 2101/00 Articles made by soldering, welding or cutting
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23K 2103/26 Alloys of Nickel and Cobalt and Chromium
• CPC Class Codes: B23K 26/32 taking account of the properties of the material involved
• CPC Class Codes: B23K 26/34 Laser welding for purposes other than joining
• CPC Class Codes: B23K 26/342 Build-up welding
• CPC Class Codes: B23K 35/0244 Powders, particles or spheres; Preforms made therefrom
• CPC Class Codes: B23K 35/3033 Ni as the principal constituent
• CPC Class Codes: B23K 35/304 with Cr as the next major constituent
• CPC Class Codes: B23K 35/3046 Co as the principal constituent
• CPC Class Codes: B23K 9/04 Welding for other purposes than joining, e.g. built-up welding

Abstract

A process is provided for welding a nickel or cobalt based superalloy article to minimize cracking by preheating the entire weld area to a maximum ductility temperature range, maintaining such temperature during welding and solidification of the weld, raising the temperature for stress relief of the superalloy, then cooling at a rate effective to minimize gamma prime precipitation.

Claims

1. A process for welding a nickel and/or cobalt based superalloy article comprising:

preheating an entire weld area and region adjacent to the weld area of the article to a maximum ductility temperature range which is above an aging temperature and below an incipient melting temperature for said superalloy and maintaining such temperature during welding and solidification of a weld;

raising the temperature of the welded article to a stress relieving temperature; and

cooling the article to below the gamma prime precipitation hardening range at a rate effective to minimize additional gamma prime precipitation.

2. Process of claim 1 wherein the superalloy article is chosen from the group consisting of a gamma-prime precipitation strengthened superalloy containing titanium and aluminum in a combined amount of at least 5%.

3. Process of claim 2 wherein the article is cooled at a rate of at least 100°

F. per minute.

4. Process of claim 3 wherein the maximum ductility temperature range is within the range of 1400°

F. to 2100°

F.

5. Process of claim 4 wherein welding is carried out with a powder alloy which is a gamma-prime precipitation-strengthened nickel base superalloy containing titanium and aluminum in a combined amount of at least 5%.

6. Process of claim 5 wherein the superalloy article and the powder alloy comprise substantially the same alloy.

7. Process of claim 6 wherein the superalloy article is a component for a gas turbine engine.

8. Process of claim 7 wherein the article is a turbine blade, turbine vane or turbine rotor.

9. Process of claim 8 further comprising machining the welded article.

10. Process of claim 5 wherein the article is cooled at a rate of at least 116°

F. per minute.

11. Process of claim 10 wherein the superalloy is In 738LC and the maximum ductility temperature range is from 1800°

to 1900°

F.

12. Process of claim 10 wherein the superalloy is R′

80 and the maximum ductility temperature range is from 1925 to 2100°

F.