Accession Number:

AD0748349

Title:

Investigation of the Hot Corrosion Mechanism in Nickel-8 Chromium-6 Aluminum.

Descriptive Note:

Master's thesis,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING

Personal Author(s):

Report Date:

1972-06-01

Pagination or Media Count:

61.0

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

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE