Aqueous corrosion characteristics and corrosion-related cracking susceptibilities of Fe sub 3 Al-type iron aluminides

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

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

Buchanan, R A; Kim, J G ^[1]

---

1. Tennessee Univ., Knoxville, TN (USA). Dept. of Materials Science and Engineering

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. 32 refs., 19 figs., 11 tabs.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Tennessee Univ., Knoxville, TN (USA). Dept. of Materials Science and Engineering
• Sponsoring Organization: USDOE; USDOE, Washington, DC (USA)
• 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
ALUMINIUM ALLOYS
CORROSION
CHROMIUM ALLOYS
HYDROCHLORIC ACID
CORROSIVE EFFECTS
IRON BASE ALLOYS
NICKEL ALLOYS
SODIUM CHLORIDES
SODIUM HYDROXIDES
SULFURIC ACID
CORROSION RESISTANCE
ELECTROCHEMICAL CORROSION
MOLYBDENUM ADDITIONS
PH VALUE
POLARIZATION
ALKALI METAL COMPOUNDS
ALLOYS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXIDES
INORGANIC ACIDS
IRON ALLOYS
MOLYBDENUM ALLOYS
OXYGEN COMPOUNDS
SODIUM COMPOUNDS
360105* - Metals & Alloys- Corrosion & Erosion