Effect of Applied Electric Fields on the Mechanisms of Oxidation of Metals and Alloys.
Abstract
An exploratory study was made of the effects of applied electrical potentials on the oxidation/hot corrosion behavior of Nichrome, nickel, and Kanthal in seeded propane/air flames. Temperatures were maintained at about 1200C. Typical seed materials, vaporized into the flame from a nickel crucible, included K2CO3, K2SO4, and Na2CO3. The alkali metal ions were used to increase the conductivity of the flame; K2SO4 served as a source of sulfur as well. In several experiments SO2(g) was introduced separately from the alkali metal seed. In one series of experiments, Nichrome samples were coated with sodium sulfate salt and tested in unseeded flames. Sheet samples were polarized at voltages of -300 to +300 V with respect to various counter electrodes. In all the experiments on nickel based samples, it was found that negative polarization (sample cathodic) drastically accelerated scaling reactions and often altered scale morphology, leading to deep grain boundary penetration of corrosion products. When the samples were polarized anodically, the reaction rate was visibly lower than observed cirucit potential. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 15, 1971
- Accession Number
- AD0728825
Entities
People
- Joan B. Berkowitz-mattuck
- John M. Ketteringham
- Wilson P. Menashi
Organizations
- Arthur D. Little