Method for limiting surface recrystallization

Patent metadata

Field	Value
Publication number	US-9551053-B2
Application number	US-201113167233-A
Country	US
Kind code	B2
Filing date	Jun 23, 2011
Priority date	Jun 23, 2011
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

A method to limit surface zone recrystallization in a superalloy article includes limiting recrystallization in a surface zone of a superalloy article by treating the superalloy article in an oxygen-containing environment to introduce oxygen into the surface zone in an amount sufficient to pin any new grain boundaries in the surface zone.

First claim

What is claimed is:

1. A superalloy article comprising:
a nickel-based superalloy body that has a surface zone, the surface zone including oxygen dopant in an amount sufficient to pin any new grain boundaries in the surface zone that occur under a recrystallization condition of 1080° C./1976° F. for 4 hours, the amount of oxygen dopant being insufficient to produce a continuous oxide scale on the surface of the nickel-based superalloy body.

2. The superalloy article as recited in claim 1 , wherein the superalloy body includes a subsurface zone under the surface zone, and the subsurface zone includes less oxygen than the surface zone.

3. The superalloy article as recited in claim 1 , wherein the nickel-based superalloy body is a single-crystal nickel-based superalloy.

4. The superalloy article as recited in claim 1 , wherein the nickel-based superalloy has a nominal composition of 6.5 wt % chromium, 9 wt % cobalt, 0.6 wt % molybdenum, 3 wt % rhenium, 6 wt % tungsten, 5.6 wt % aluminum, 1 wt % titanium, 6.5 wt % tantalum, 0.1 wt % hafnium, and a balance of nickel and any impurities.

5. The superalloy article as recited in claim 1 , wherein the oxygen dopant is in solution within the microstructure of the surface zone.

6. The superalloy article as recited in claim 1 , wherein the amount of oxygen dopant is insufficient to deplete the superalloy article of gamma prime phase.

7. The superalloy article as recited in claim 1 , wherein a recrystallization temperature of the surface zone is lower than a recrystallization temperature of a subsurface zone under the surface zone.

8. The superalloy article as recited in claim 1 , wherein an area of the surface zone includes the oxygen dopant and another area of the surface zone excludes oxygen dopant.

9. The superalloy article as recited in claim 8 , wherein the area that excludes oxygen dopant has low residual stress relative to the area having oxygen dopant.

10. The superalloy article as recited in claim 8 , wherein the area that excludes oxygen dopant has low defect density relative to the area having oxygen dopant.

11. The superalloy article as recited in claim 8 , wherein the superalloy body is an airfoil having a root portion and a blade portion connected to the root portion, and the area having oxygen dopant is the root portion and the area that excludes oxygen dopant is the blade portion.

Assignees

• Kononenko Yuriy G
• Belousov Igor V
• Bondarchuk Vadim Ivanovich
• Marynskyi Andrii
• Soderberg Carl R
• United Technologies Corp

Inventors

• Kononenko Yuriy G
• Belousov Igor V
• Bondarchuk Vadim Ivanovich
• Marynskyi Andrii
• Soderberg Carl R

Classifications

• C22C19/057

  with the maximum Cr content being less 10% · CPC title

• C22C19/05

  with chromium · CPC title

• Y10T428/12944

  Ni-base component · CPC title

• C22F1/00 Primary

  Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working (apparatus for mechanical working of metal B21, B23, B24) · CPC title

• C21D2201/04

  Single or very large crystals · CPC title