scholarly journals The intergranular oxidation susceptibility of thermally–treated Alloy 600

2017 ◽  
Vol 114 ◽  
pp. 112-122 ◽  
Author(s):  
G. Bertali ◽  
F. Scenini ◽  
M.G. Burke
Keyword(s):  
Alloy 600 ◽  
Intergranular Oxidation ◽  
Oxidation Susceptibility ◽  
Thermally Treated

PWSCC of thermally treated alloy 600 pulled from a Korean plant

2002 ◽  
Vol 217 (3) ◽  
pp. 237-245 ◽  
Author(s):  
Seong Sik Hwang ◽  
Do Haeng Hur ◽  
Jung Ho Han ◽  
Joung Soo Kim
Keyword(s):  
Alloy 600 ◽  
Thermally Treated

Characterization of initial intergranular oxidation processes in alloy 600 at a sub-nanometer scale

2018 ◽  
Vol 133 ◽  
pp. 36-47 ◽  
Author(s):  
S.Y. Persaud ◽  
B. Langelier ◽  
A. Korinek ◽  
S. Ramamurthy ◽  
G.A. Botton ◽  
...  
Keyword(s):  
Nanometer Scale ◽  
Alloy 600 ◽  
Oxidation Processes ◽  
Intergranular Oxidation

U.S. Operating Experience With Thermally Treated Alloy 600 Steam Generator Tubes

2002 ◽  
Author(s):  
April Smith ◽  
Kenneth J. Karwoski
Keyword(s):  
Steam Generator ◽  
Operating Experience ◽  
Alloy 600 ◽  
Steam Generators ◽  
Pressurized Water ◽  
Steam Generator Tube ◽  
Water Reactors ◽  
1960S And 1970S ◽  
The 1960S ◽  
Thermally Treated

Steam generators placed in service in the 1960s and 1970s were primarily fabricated from mill-annealed Alloy 600. Over time, this material proved to be susceptible to stress corrosion cracking in the highly pure primary and secondary water chemistry environments of pressurized-water reactors. The corrosion ultimately led to the replacement of steam generators at numerous facilities, the first U.S. replacement occurring in 1980. Many of the steam generators placed into service in the 1980s used tubes fabricated from thermally treated Alloy 600. This tube material was thought to be less susceptible to corrosion. Because of the safety significance of steam generator tube integrity, this paper evaluates the operating experience of thermally treated Alloy 600 by looking at the extent to which it is used and recent results from steam generator tube examinations.

SIMS/AEM Characterization of Banded Microstructures in an Ni-Cr-Fe Alloy

1999 ◽  
Vol 5 (S2) ◽  
pp. 862-863 ◽  
Author(s):  
M.G. Burke ◽  
B.Z. Hyatt ◽  
G. McMahon
Keyword(s):  
Aging Temperature ◽  
Single Phase ◽  
Alloy 600 ◽  
Solution Annealing ◽  
Grain Sizes ◽  
Treated Condition ◽  
Alloy 690 ◽  
Fe Alloys ◽  
Thermally Treated

Ni-Cr-Fe alloys such as Alloy 600 and Alloy 690 are single phase fee alloys with excellent resistance to corrosion. Alloy 600 is generally used in a thermally-treated condition which is characterized by the intergranular precipitation of Cr-rich M7C3 and, depending upon the aging temperature, Cr-rich M23C6. These alloys are usually cast and processed by rolling or forging. These alloys can exhibit microstructures in which there are nonuniform distributions of intragranular carbides that appear as bands aligned parallel to the working direction (i.e. longitudinal) of the material. It is also possible for these materials to exhibit duplex grain sizes which can be associated with the banded carbide structure. Banded microstructures can become more prominent after further anneals. The resistance of the carbide bands to dissolution during solution annealing at temperatures up to 1150°C has prompted the further evaluation of banding in Alloy 600, specifically in terms of identifying those elements associated with the carbide bands.

Effects of Pb on SCC of Alloy 600 and Alloy 690 in Prototypical Steam Generator Chemistries

2005 ◽  
Vol 475-479 ◽  
pp. 1387-1392 ◽  
Author(s):  
Jesse Lumsden ◽  
Allan McIlree ◽  
Richard Eaker ◽  
Rocky Thompson ◽  
Steve Slosnerick
Keyword(s):  
Steam Generator ◽  
Open Circuit Potential ◽  
Film Formation ◽  
Open Circuit ◽  
Alloy 600 ◽  
Steam Generators ◽  
Film Rupture ◽  
Test Environment ◽  
Alloy 690 ◽  
Thermally Treated

Intergranular attack/stress corrosion cracking of Alloy 600 continues to be an issue in the tube/tube support plate crevices and top of tubesheet locations of recirculating steam generators and in the upper bundle of free span superheated regions of once through steam generators (OTSG). Recent examinations of degraded pulled tubes from several plants suggest possible lead involvement in the degradation. Laboratory investigations have been performed to determine the factors influencing lead cracking in Alloy 600 and Alloy 690 steam generator tubes. The test environment is believed to be prototypical, with the addition of lead oxide, of a concentrated liquid phase existing in the pores of thin deposits on upper bundle tubes of an OTSG. Highly strained reverse U-bend specimens were tested at controlled electrochemical potentials. Maximum susceptibility was at open circuit potential, unlike cracking of Alloy 600 in caustic and acid sulfate environments where maximum susceptibility occurs when specimens are polarized above the open circuit potential. Transgranular, intergranular and mixed mode cracking was observed and in all Alloy 600 conditions tested (mill annealed, sensitized, thermally treated) while thermally treated Alloy 690 has so far resisted cracking. A film rupture/anodic dissolution model with displacement plating of Pb preceding passive film formation is consistent with the experimental observations

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