Mitigation of stress corrosion cracking of structural materials exposed to a high temperature water

• US 7,264,770 B2
• Filed: 05/02/2005
• Issued: 09/04/2007
• Est. Priority Date: 05/02/2005
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Morra, Martin Mathew, Kim, Young-Jin, Andresen, Peter Louis, Diaz, Thomas Pompilio, Angeliu, Thomas Martin, Hettiarachchi, Sam
• Primary Examiner(s): Bell; Bruce F.
• Application Number:
  US11/120,478
• Publication Number:
  US 20060243602A1
• Time in Patent Office: 855 Days
• Field of Search: 422/7, 422/11, 422/12, 422/14, 422/19, 376/277, 376/305, 376/306
• US Class Current: 422/7
• CPC Class Codes: B01J 23/06 of zinc, cadmium or mercury
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/40 characterised by dimensions, e.g. grain size in a colloidal state B01J35/23; crystallite size B01J35/77
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C02F 1/70 by reduction C02F1/4676 takes precedence
• CPC Class Codes: C02F 2103/023 Water in cooling circuits
• CPC Class Codes: C02F 2303/08 Corrosion inhibition
• CPC Class Codes: C02F 2305/08 Nanoparticles or nanotubes
• CPC Class Codes: C23F 11/187 Mixtures of inorganic inhibitors
• CPC Class Codes: C23F 15/00 Other methods of preventing corrosion or incrustation
• CPC Class Codes: F05B 2260/95 Preventing corrosion coating or surface treatment F05B2230/90
• CPC Class Codes: G21C 19/307 specially adapted for liquids decontamination of liquids G21F9/04
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

A method for mitigating stress corrosion cracking of a component exposed to a high temperature water in a high temperature water system is provided. The method comprises the steps of lowering corrosion potential conditions to a desired low corrosion potential in the high temperature water environment; and introducing a first material comprising zinc into the high temperature water environment, such that the desired low corrosion potential facilitates transport of the first material into cracks in a structure communicative with the high temperature water environment.

Claims

1. A method for mitigating stress corrosion cracking of a component exposed to a high temperature water in a high temperature water system, the method comprising:

reducing corrosion potential conditions to a desired low corrosion potential in the high temperature water environment; and

introducing a first material comprising zinc into the high temperature water environment, such that the desired low corrosion potential facilitates transport of the first material into cracks in a structure communicative with the high temperature water environment.

2. The method of claim 1, wherein reducing corrosion potential conditions comprises introducing a plurality of catalytic nanoparticles including a second material into the high temperature water environment.

3. The method of claim 2, wherein the second material comprises a noble metal including palladium, or platinum, or osmium, or rhodium, or ruthenium, or iridium, or rhenium, or oxides thereof, or nitrides thereof, or borides thereof, or combinations thereof, or alloys thereof.

4. The method of claim 2, wherein the plurality of catalytic nanoparticles has an average particle size of less than 500 nm.

5. The method of claim 2, wherein introducing the plurality of catalytic nanoparticles comprises providing a concentration of the plurality of catalytic nanoparticles in the high temperature water environment in a range from about 5 parts per billion to about 200 parts per billion.

6. The method of claim 1, wherein reducing corrosion potential conditions comprises introducing a plurality of dielectric nanoparticles comprising a second material.

7. The method of claim 6, wherein said plurality of dielectric nanoparticles comprises a non-noble metal including zirconium, or hafnium, or niobium, or tantalum, or yttrium, or tungsten, or vanadium, or titanium, or molybdenum, or chromium, or cerium, or germanium, or scandium, or lanthanum, or oxides thereof, or combinations thereof.

8. The method of claim 1, wherein reducing corrosion potential conditions to the desired low corrosion potential comprises providing an effective amount of a second material to lower the corrosion potential to a value in the range from about −

500 milli volts to about 100 milli volts with respect to a standard hydrogen electrode.

9. The method of claim 8, wherein reducing corrosion potential conditions to the desired low corrosion potential comprises providing an effective amount of a second material to lower the corrosion potential to a value less than 0 millivolts with respect to a standard hydrogen electrode.

10. The method of claim 1, wherein reducing corrosion potential conditions comprises introducing a reducing species.

11. The method of claim 10, wherein said reducing species comprises one including hydrogen, or alcohol, or hydrazine, or ammonia, or combinations thereof.

12. The method of claim 1, wherein introducing the first material comprises introducing a plurality of nanoparticles comprising the first material.

13. The method of claim 1, wherein the first material comprises metallic zinc, or zinc oxide, or zinc nitrate, or zinc acetate, or combinations thereof.

14. A method for mitigating stress corrosion cracking, comprising:

reducing corrosion potential via introducing a plurality of catalytic nanoparticles in a high temperature water system; and

inducing, via an effective reduction of corrosion potential, entry of a material comprising zinc into a stress crack in a component in the high temperature water system.

15. The method of claim 14, wherein introducing the plurality of catalytic nanoparticles comprises introducing a source of catalytic nanoparticles and zinc into the high temperature water in the form of a powder, or a slurry, or a pellet, or a coated substrate, or a coating, or a chemical alloy or a mechanical alloy or in a non dispersed metallic form, or combinations thereof.

16. The method of claim 15, wherein introducing the source of catalytic nanoparticles and zinc into the high temperature water comprises achieving a predetermined concentration of catalytic particles and zinc in the high temperature water.

17. The method of claim 15, wherein introducing the source of catalytic nanoparticles and zinc into the high temperature water comprises continuously or intermittently delivering a predetermined amount of the source.

18. The method of claim 15, wherein the source of catalytic nanoparticle and the material comprising zinc are introduced together.

19. A method for mitigating stress corrosion cracking, comprising:

catalytically recombining oxidants and reductants to reduce corrosion potential in a high temperature water system; and

inducing, via an effective reduction of corrosion potential, entry of a first material comprising zinc into a stress crack in a component in the high temperature water system.

20. The method of claim 19, wherein the plurality of the nanoparticles have a mean particle size less than about 500 nanometers.

21. The method of claim 19, wherein the high temperature water system is a nuclear reactor, or a steam turbine, or a water deareator, or a jet pump.

22. The method of claim 21, wherein the nuclear reactor is a boiling water nuclear reactor.

23. The method of claim 19, wherein introducing the first material comprises introducing a plurality of nanoparticles comprising the first material.

24. A method for mitigating stress corrosion cracking, comprising:

reducing corrosion potential conditions in a high temperature water environment;

inducing, via an effective reduction of the corrosion potential conditions, entry of a material comprising zinc into a stress crack in a component in the high temperature water system; and

preventing or substantially reducing further growth of the stress crack via the entry of the material comprising zinc into the stress crack.