Aqueous Corrosion Characteristics and Corrosion-Related Cracking Susceptibilities of Fe₃Al-Type Iron Aluminides

Technical Report · Mon Apr 01 04:00:00 EST 1991

DOI:https://doi.org/10.2172/5593944· OSTI ID:5593944

Buchanan, R. A. ^[1]; Kim, J. G. ^[1]

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1. Univ. of Tennessee, Knoxville, TN (United States)

In certain fossil-energy applications, iron aluminides may be subjected to ambient-temperature aqueous corrosion conditions. In the present project, the aqueous corrosion characteristics and the cracking tendencies under aqueous-corrosion conditions were studied. In these studies, electrochemical, immersion and electrochemical-mechanical evaluation techniques were employed. For a range of iron-aluminide compositions, cyclic anodic polarization tests were conducted in a number of electrolytes to provide information on anodic dissolution characteristics including tendencies for either active uniform corrosion, localized corrosion, or passivation. Average corrosion penetration rates were determined by application of Tafel methods or the polarization-resistance method in combination with Faraday's law. Immersion test methods were employed to verify corrosion behavior as determined by electrochemical methods and to evaluate localized-corrosion initiation times. U-bend corrosion tests were conducted at open-circuit corrosion potentials and at potentiostatically-controlled anodic and cathodic potentials to investigate the cracking tendencies of selected iron aluminides and to provide information on the cracking mechanism. And finally, slow-strain-rate corrosion tests were conducted at open-circuit and potentiostatically-controlled cathodic potentials to study the ductility response as related to cracking tendencies and the mechanism responsible.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy and Carbon Management (FECM)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5593944
• Report Number(s): ORNL/Sub--88-07685/01; ON: DE91013028
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM ALLOYS
CORROSION
CORROSION RESISTANCE
CORROSIVE EFFECTS
ELECTROCHEMICAL CORROSION
HALIDES
HALOGEN COMPOUNDS
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
HYDROXIDES
INORGANIC ACIDS
IRON ALLOYS
IRON BASE ALLOYS
MOLYBDENUM ADDITIONS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
OXYGEN COMPOUNDS
PH VALUE
POLARIZATION
SODIUM CHLORIDES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SULFURIC ACID