Changes in the mechanical properties of Hastelloy X when exposed to a typical gas-cooled reactor environment

Conference · Thu Jan 01 04:00:00 EST 1981

OSTI ID:6079296

McCoy, Jr, H E

The helium used in a gas-cooled reactor will contain small amounts of H/sub 2/, CO, CH/sub 4/, H/sub 2/O, and N/sub 2/ which can lead to oxidation and carburization/decarburization of structural materials. Long-term creep tests were run on Hastelloy X to 30,000 h at 649 to 871/sup 0/C. It was found that extensive carburization occurred, the minimum creep rate and time to rupture were equal in air and impure helium environments, and the fracture strain was less in helium than in air. Thermal exposure in the temperature range of 538 to 871/sup 0/C resulted in the reduction of ductility in impact and tensile tests at ambient temperature, and this reduction was greater when the exposure was in impure helium rather than in air. A modified alloy with lower chromium and 2% titanium resisted carburization.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6079296
• Report Number(s): CONF-810913-8; ON: DE81030918
• Country of Publication: United States
• Language: English

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CHEMICAL REACTIONS
CHROMIUM ALLOYS
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CORROSION
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RARE GASES
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