Investigation of the Hot Corrosion Mechanism in Nickel-8 Chromium-6 Aluminum.
Abstract
The mechanism of hot corrosion in a nickel-chromium-aluminum alloy was investigated. The effects of three sodium salts (sulfate, carbonate, and nitrate) were studied at 100C in 150 torr oxygen; additionally, tests were conducted with sodium sulfate at 900C in oxygen and at 1000C in argon. Continuous gravimetric data were taken for each experiment; corroded specimens were analyzed using X-ray diffraction, metallographic, and electron microprobe techniques. The hot corrosion mechanism involves a sequence of events; formation of an oxide layer, formation of subsurface chromium sulfides, dissolution of the protective oxide scale, and oxidation of the sulfides and the chromium-depleted substrate. The role of sulfur in the hot corrosion process is the depletion of chromium in the alloy; the alloy is thus susceptible to increased oxidation. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1972
- Accession Number
- AD0748349
Entities
People
- Nathan J. Adams Jr
Organizations
- Air Force Institute of Technology