Fe{sub 3}Al-type iron aluminides: Aqueous corrosion properties in a range of electrolytes and slow-strain-rate ductilities during aqueous corrosion

Technical Report · Sat Aug 01 04:00:00 EDT 1992

DOI:https://doi.org/10.2172/10178708· OSTI ID:10178708

Buchanan, R A; Kim, J G ^[1]

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

The Fe{sub 3}Al-type iron aluminides have undergone continued development at the Oak Ridge National Laboratory for enhancement of mechanical and corrosion properties. Improved alloys and thermomechanical processing methods have evolved. The overall purpose of the project herein described was to evaluate the aqueous corrosion properties of the most recent alloy compositions in a wide range of possibly-aggressive solutions and under several different types of corrosion-test conditions. The work supplements previous aqueous-corrosion studies on iron aluminides by the present authors. Four stages of this one-year aqueous-corrosion investigation are described. First the corrosion properties of selected iron aluminides were evaluated by means of electrochemical tests and longer-time immersion tests in a range of acidic, basic and chloride solutions. Theses tests were performed under non-crevice conditions, i.e. the specimens were not designed to contain crevice geometries. Second, the iron-aluminide alloy that proved most resistance to chloride-induced localized corrosion under non-crevice conditions was further evaluated under more-severe crevice conditions by electrochemical and immersion testing. Third, in order to study the relative roles of Fe, Al, Cr and Mo in the formation of passive films, the chemical compositions of passive films were determined by X-ray photoelectron spectroscopy (XPS). And fourth, in order to study aqueous-corrosion effects on the ductilities of iron aluminides as related to hydrogen embrittlement and/or stress-corrosion cracking, slow-strain-rate corrosion (SSRC) tests were conducted over a range of electrochemical potentials.

• Research Organization: Oak Ridge National Lab., TN (United States); Tennessee Univ., Knoxville, TN (United States). Dept. of Materials Science and Engineering
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 10178708
• Report Number(s): ORNL/SUB--88-07685CT92/02; ON: DE92040520
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105
ALUMINIUM COMPOUNDS
AQUEOUS SOLUTIONS
CHLORIDES
CORROSION AND EROSION
CORROSION RESISTANCE
CORROSIVE EFFECTS
CREVICE CORROSION
DUCTILITY
ELECTROCHEMICAL CORROSION
EXPERIMENTAL DATA
HYDROCHLORIC ACID
HYDROGEN
INTERMETALLIC COMPOUNDS
IRON COMPOUNDS
METALLURGICAL EFFECTS
PITTING CORROSION
SODIUM HYDROXIDES
SULFURIC ACID