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High-cycle fatigue behavior of Incoloy alloy 800H in a simulated HTGR helium environment containing high moisture levels

Journal Article · · Nucl. Technol.; (United States)
OSTI ID:6478037

A study has been carried out to evaluate the highcycle fatigue strength of Incoloy alloy 800H in a high-temperature gas-cooled reactor helium environment containing significant quantities of moisture. As-heat-treated and thermally aged materials were tested to determine the effects of long-term oxidation in the helium test gas. Results from these tests were compared to those for a standard air environment. It was found that the mechanisms of fatigue failure were complex and involved recovery/recrystallization of the surface-ground layer on the specimens, sensitization, work hardening, oxide scale integrity, and oxidation at the tips of propagating cracks. For certain situations, a corrosion-fatigue process seems to be important. However, for the helium environment studied, the fatigue strength was nearly always higher than that for air.

Research Organization:
Brookhaven National Laboratory, Upton, New York 11973
OSTI ID:
6478037
Journal Information:
Nucl. Technol.; (United States), Journal Name: Nucl. Technol.; (United States) Vol. 66:2; ISSN NUTYB
Country of Publication:
United States
Language:
English