Methods of brazing wide gaps in nickel base superalloys without substantial degradation of properties

Patent metadata

Field	Value
Publication number	US-9839980-B2
Application number	US-201615098389-A
Country	US
Kind code	B2
Filing date	Apr 14, 2016
Priority date	Apr 14, 2016
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

Nickel base superalloys, including in some embodiments 5% to 7% Fe, which were previously developed and used for their corrosion resistance, also possess favorable characteristics for use as a braze filler in repair or joining of superalloy substrates, such as those used to form turbine engine blades and vanes, heat exchangers, vessels, and piping. In particular, such corrosion-resistant nickel base superalloys have favorable characteristics for wide-gap brazing of gaps greater than one millimeter in superalloy substrates that preserves favorable material properties throughout the braze region in the substrate.

First claim

What is claimed is:

1. A method of brazing a gap in a Ni base superalloy substrate consisting essentially of:
providing a braze alloy having substantially the following composition in weight percent:
Cr: 20%-22%; and,
Fe: 5%-7%; and,
Si: 5%-10%; and,
Mo: 1.5%-10%; and,
Cu: 0.2%-2%; and,
C: 0%-0.03%; and, optionally, one or more of;
Al: greater than 0% and less than approximately 3%; and,
Ti: greater than 0% and less than approximately 7%; and,
Hf: greater than 0% and less than approximately 1.5%; and,
Nb: greater than 0% and less than approximately 1%; and,
Zr: greater than 0% and less than approximately 6%; and,
B: greater than 0% and less than approximately 1%; and,
the balance of the braze alloy is Ni; and,

delivering the braze alloy to a gap in the substrate, wherein the gap is too wide for diffusion brazing; and
brazing the gap having the braze alloy therein at a temperature that is the lower of 1180 degrees Celsius or a temperature that is above liquidus temperature of the braze alloy but below solidus temperature of the substrate; and,
allowing the braze alloy to solidify creating thereby a braze zone.

2. A method of brazing a gap in a Ni base superalloy substrate as in claim 1 wherein the braze alloy has substantially the following composition in weight percent:
Cr: 20%; and,
Fe: 6%; and,
Si: 5%; and,
Mo: 2.5%; and,
Cu: 2%; and,
C: 0%-0.03%; and,
the balance of the braze alloy is Ni.

3. A method of brazing a gap in a Ni base superalloy substrate as in claim 1 wherein the gap having brazing alloy therein is at least 1 millimeter wide in some portion of the brazing zone.

4. A method of brazing a gap in a Ni base superalloy substrate as in claim 2 wherein the gap having brazing alloy therein is at least 1 millimeter wide in some portion of the brazing zone.

5. A method of brazing a gap in a Ni base superalloy substrate as in claim 3 wherein at least one of the following properties of the braze zone is at least 70% of the corresponding property of the Ni base superalloy: ultimate tensile strength, yield strength, elongation or corrosion resistance.

6. A method of brazing a gap in a Ni base superalloy substrate as in claim 4 wherein at least one of the following properties of the braze zone is at least 70% of the corresponding property of the Ni base superalloy: ultimate tensile strength, yield strength, elongation or corrosion resistance.

Assignees

• Siemens Energy Inc

Inventors

• Bruck Gerald J

Classifications

• B23K1/00 Primary

  Soldering, e.g. brazing, or unsoldering (B23K3/00 takes precedence) · CPC title

• B23K1/0018 Primary

  Brazing of turbine parts · CPC title

• C22C19/05

  with chromium · CPC title

• B23K35/0222

  for use in soldering or brazing (B23K35/0205 takes precedence) · CPC title

• B23P6/007

  using only additive methods, e.g. build-up welding · CPC title