Effect of alloying elements on passivity and breakdown of passivity of Fe- and Ni-based alloys mechanistics aspects. Annual report, August 1, 1991--July 31, 1992
On the basis of the literature data and the current results, the mechanism of pitting corrosion of Al-alloys is proposed. An assumption is made that the transport of Cl- ions through defects in the passive film of aluminum an aluminum alloys is not a rate determining step in pitting. The pit development is controlled by the solubility of the oxidized alloying elements in acid solutions. A very good correlation was found between the pitting potential and the oxidized alloying elements for metastable Al-Cr, Al-Zr, Al-W, and Al-Zn alloys. We expect that the effect of oxidized alloying elements in other passive alloys will be the same as in Al-alloys. To verify this hypothesis, susceptibility to pitting in the function of alloying elements in the binary alloys and the composition of the oxide film has to be measured. We propose studying Fe- and Ni-alloys produced by a sputtering deposition method. Using this method one-phaseous alloy can be obtained, even when the two metals are immiscible using conventional methods. Another advantage to studying sputtered alloys is to find new materials with superior resistance to localized corrosion.
- Research Organization:
- Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG02-87ER45293
- OSTI ID:
- 10160885
- Report Number(s):
- DOE/ER/45293-5; ON: DE92017316
- Resource Relation:
- Other Information: PBD: Jun 1992
- Country of Publication:
- United States
- Language:
- English
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