Effects of methane concentration on the controlled-impurity helium corrosion behavior of selected HTGR structural materials
The corrosion behavior of candidate structural alloys in a series of three simulated advanced gas-cooled reactor environments at 900/sup 0/C (1652/sup 0/F), with methane concentration varied, is discussed. The alloys investigated include three wrought alloys, Hastelloy X, Inconel 617, and Incoloy 800H; two cast superalloys, Rene 100 and IN 713; one centrifugally cast alloy, HK 40; and an oxide-dispersion-strengthened alloy, MA 754. Corrosion behavior was found to be strongly dependent upon both the alloy chemistry and the environment. Oxidation, carburization, and/or mixed behavior was observed depending upon the specific conditions. An equilibrium thermodynamics approach has been used to predict alloy behavior and explain observations relevant to the understanding of gas/metal interactions in reactor helium, which inherently contains small amounts of reactive impurity species. Carburization was identified as the primary corrosion phenomenon of concern, and detailed analyses were performed to determine the susceptibility and control of carburization reactions. The presence of alumina scales, containing small amounts of titanium, was found to be particularly effective in inhibiting carburization. Small variations in methane concentration have been shown to have a dramatic effect upon the oxidation potential and subsequent corrosion behavior of the alloy systems.
- Research Organization:
- General Atomics, San Diego, CA (United States)
- DOE Contract Number:
- AT03-76ET35300
- OSTI ID:
- 5744928
- Report Number(s):
- GA-A-15565; TRN: 80-004453
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
HASTELLOY X
CORROSION
HTGR TYPE REACTORS
REACTOR MATERIALS
INCOLOY 800
INCONEL 617
INCONEL ALLOYS
METHANE
CORROSIVE EFFECTS
NICKEL BASE ALLOYS
RENE-100
CARBURIZATION
OXIDATION
ALKANES
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COBALT ALLOYS
CRYOGENIC FLUIDS
FLUIDS
GAS COOLED REACTORS
GRAPHITE MODERATED REACTORS
HARDENING
HASTELLOYS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HYDROCARBONS
INCOLOY ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
ORGANIC COMPOUNDS
REACTORS
SURFACE HARDENING
SURFACE TREATMENTS
TITANIUM ALLOYS
TUNGSTEN ALLOYS
210300* - Power Reactors
Nonbreeding
Graphite Moderated
360105 - Metals & Alloys- Corrosion & Erosion