Effects of oxidation on the impact energy of Hastelloy S and Hastelloy C-4 Charpy V-notch specimens heated in air at 600 to 800
The /sup 90/SrF/sub 2/ heat source being developed at PNL utilizes a Hastelloy S or Hastelloy C-4 outer capsule having a 0.5-in.-thick wall to contain the Hastelloy C-276 inner capsule. The primary objective of the study was to demonstrate that the air oxidation of the outer capsule that could occur during heat-source service would not degrade the ductility and Charpy impact strength of the capsule below the licensing requirements given in Section 1.1. The /sup 90/SrF/sub 2/ heat source under development is intended for general-purpose use. Compatibility considerations limit the interface temperature between the /sup 90/SrF/sub 2/ and Hastelloy C-276 inner capsule to a maximum of 800/sup 0/C. The outer capsule surface temperature will be somewhat less than 800/sup 0/C, and depending on the service, may be substantially lower. The oxidation tests were therefore carried out at 600/sup 0/ to 800/sup 0/C for exposures up to 10,000h to cover the range of temperature the outer capsule might expect to encounter in service. The results showed that the oxidation of Hastelloy S and Hastelloy C-4 in air at 600/sup 0/ to 800/sup 0/C is very slow, and both alloys form adherent oxide layers that serve to protect the underlying metal. Subsurface attack of Hastelloy S and Hastelloy C-4 due to oxidation was greater than expected, considering the slow oxidation rates of the two alloys at 600/sup 0/ to 800/sup 0/C. Estimates of subsurface attack, determined from micrographs of the oxidized specimens, showed erratic results and it was impossible to assign any type of rate equation to the subsurface attack. A conservative estimate of long-term effects can be made using a linear extrapolation of the test results. There were no significant differences between the room-temperature Charpy impact energy of Hastelloy S and Hastelloy C-4 specimens oxidized in air at 600/sup 0/ to 800/sup 0/C and control specimens heated in vacuum.
- Research Organization:
- Battelle Pacific Northwest Labs., Richland, WA (United States)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 6730746
- Report Number(s):
- PNL-3641; TRN: 81-003815
- Country of Publication:
- United States
- Language:
- English
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Quarterly report on the strontium heat source development program, advanced systems and materials production division for July-September 1978.
Air oxidation and seawater corrosion of Hastelloy S and Hastelloy C-4
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36 MATERIALS SCIENCE
CAPSULES
MATERIALS
HASTELLOY S
IMPACT STRENGTH
MICROSTRUCTURE
OXIDATION
HASTELLOYS
RADIOISOTOPE HEAT SOURCES
EXPERIMENTAL DATA
IMPACT TESTS
STRONTIUM 90
ALKALINE EARTH ISOTOPES
ALLOYS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL REACTIONS
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CONTAINERS
CRYSTAL STRUCTURE
DATA
EVEN-EVEN NUCLEI
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HEAT SOURCES
INFORMATION
INTERMEDIATE MASS NUCLEI
IRON ALLOYS
ISOTOPES
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NUCLEI
NUMERICAL DATA
RADIOISOTOPES
STRONTIUM ISOTOPES
TESTING
YEARS LIVING RADIOISOTOPES
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070300* - Isotopic Power Supplies
360103 - Metals & Alloys- Mechanical Properties