Accession Number : AD0770858

Title :   Fundamental Studies of Dissolution and Passivity of Alloys and Compounds.

Descriptive Note : Annual rept. 1 Mar 72-28 Feb 73,


Personal Author(s) : Staehle,R. W. ; Lumsden,J. B.

Report Date : NOV 1973

Pagination or Media Count : 51

Abstract : Investigations of the properties of protective films on iron and the dissolution of bulk oxides are described. Using the techniques of ellipsometry and electrochemistry, studies have been conducted on the initial growth and dissolution of the films formed on iron surfaces exposed to a pH 8.7 borate buffer solution and to 0.1 N sodium tungstate solutions adjusted to pH's 7.4, 10, and 12. The steady state growth kinetics as well as the effects of temperature on the films also have been investigated. These results have been compared with the predictions of existing models describing film growth. The films formed in the tungstate solutions were found to be heterogeneous iron tungstates with an underlying iron oxide layer. The dissolution of the bulk oxides in a pH 0.0 chloride solution was studied. The solubility and also the rate of dissolution of Cr2O3 were found to be significantly lower than that of NiO. (Author)

Descriptors :   *Iron alloys, *Iron, *Solubility, *Passivity, Corrosion, Borates, Tungstates, Temperature, Films, Oxides, Chromium compounds, Nickel compounds, Reaction kinetics, Chlorides, Sulfuric acid

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE