Accession Number : AD0634183

Title :   THE BEHAVIOR OF SUPERALLOY OXIDE FILMS IN MOLTEN SALTS.

Descriptive Note : Research and development phase rept.,

Corporate Author : NAVY MARINE ENGINEERING LAB ANNAPOLIS MD

Personal Author(s) : Wheatfall ,W. L. ; Doering ,H. ; Danek,G. J. , Jr

Report Date : JUL 1966

Pagination or Media Count : 32

Abstract : The effect of molten salts on the behavior at 1650 F of oxide films on two nickel-base superalloys and pure nickel was investigated. In the initial experiments, Na2SO4 and NaC1 were reacted with Cr2O3 and NiO in both oxidizing and reducing atmospheres. Reactions occurred only under reducing conditions. Half-cell potential as a function or time was measured to study the effects of oxide thickness, electrolyte composition and atmosphere. A sustained rise in half-cell potential always accompanied sulfidation. In Alloy A (AMS 5391A) scale formation occurred at the metal-scale interface and Na2SO4 - 5 w/o NaC1 was more corrosive than Na2SO4 alone. Sulfidation in Alloy B (AMS 5384) occurred only when NaC1 was present. On both Alloys A and B the thicker the oxide film, the longer the elapsed time to a sustained rise in half-cell potential. (Author)

Descriptors :   (*NICKEL ALLOYS, CORROSION), (*FILMS, OXIDES), CORROSION RESISTANT ALLOYS, SALTS, CORROSIVE LIQUIDS, HIGH TEMPERATURE, NICKEL COMPOUNDS, SODIUM COMPOUNDS, SULFATES, CHLORIDES, CHROMIUM COMPOUNDS, CHROMIUM ALLOYS, MOLYBDENUM ALLOYS, COBALT ALLOYS, ALUMINUM ALLOYS, TITANIUM ALLOYS, IRON ALLOYS, NICKEL, OXIDATION

Subject Categories : Coatings, Colorants and Finishes
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE