Corrosion behavior of an HVOF-sprayed Fe3Al coating in a high-temperature oxidizing/sulfidizing environment

Conference · Sat Jan 01 04:00:00 EST 2005

OSTI ID:899259

Covino, Jr, Bernard S; Bullard, Sophie J; Cramer, Stephen D; Holcomb, Gordon R; Ziomek-Moroz, Margaret; Shrestha, S ^[1]; Harvey, D ^[1]

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1. TWI Ltd.

An iron aluminide (Fe3Al) intermetallic coating was deposited onto a F22 (2.25Cr-1Mo) steel substrate using a JP-5000 high velocity oxy-fuel (HVOF) thermal spray system. The as-sprayed coating was examined by electron microscopy and X-ray diffraction and was characterized in terms of oxidation and adhesion. Fe3Al-coated steel specimens were exposed to a mixed oxidizing/sulfidizing environment at 500, 600, 700, and 800DGC for approximately seven days. The gaseous environment consisted of N2-10%CO-5%CO2-2%H2O-0.12%H2S (by volume). All specimens gained mass after exposure to the environment and the mass gains were found to be inversely proportional to temperature increases. Representative specimens exposed at each temperature were cross-sectioned and subjected to examination under a scanning electron microscope (SEM) and X-ray mapping. Results are presented in terms of corrosion weight gain and corrosion product formation. The purpose of the research presented here was to evaluate the effectiveness of an HVOF-sprayed Fe3Al coating in protecting a steel substrate exposed to a fossil energy environment.

• Research Organization: Albany Research Center (ARC), Albany, OR
• Sponsoring Organization: USDOE
• OSTI ID: 899259
• Report Number(s): DOE/ARC-2005-094
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADHESION
COATINGS
CORROSION
CORROSION PRODUCTS
ELECTRON MICROSCOPES
ELECTRON MICROSCOPY
IRON
OXIDATION
POWER PLANTS
STEELS
SUBSTRATES
VELOCITY
X-RAY DIFFRACTION
corrosion
intermetallic coating
iron aluminide
oxidizing environment
sprayed coating
sulfidizing environment