Corrosion Resistance of Metal Electrodes in an Iron Phosphate Melt

Abstract

The corrosion resistance of Inconel 690 and 693 (both nickel-based alloy) has been investigated using samples submerged in an iron phosphate melt that contained 30 wt% of the simulated Hanford low activity nuclear waste (22.6% Na 2O, 20.0% Fe 2O 3, 52.2% P 2O 5, 2.9% SO 3, and 2.3% others, wt%) at 1050°C for 155 days. The weight loss for the submerged Inconel 690 and 693 samples was 14 and 8%, respectively. The overall corrosion rate, calculated from the initial and final dimensions of each sample, was 1.3 and 0.7 μm/day for the Inconel 690 and 693, respectively. The external surface of the corroded Inconel samples was depleted in nickel and the only corrosion product found by SEM-EDS and XRD on the external surface was (Fe, Cr) 2O 3. This layer appears to act as a chemically protective layer between the metal and iron phosphate melt. These preliminary results suggest that Inconel 690 and 693 have a good corrosion resistance in iron phosphate melts, with Inconel 693 having the better corrosion resistance.

Meeting Name

106th Annual Meeting of the American Ceramic Society (2004: Apr. 18-21, Indianapolis, IN)

Department(s)

Nuclear Engineering and Radiation Science

Second Department

Materials Science and Engineering

Keywords and Phrases

Corrosion products; Corrosion rates; Iron phosphate; Metal electrodes

International Standard Serial Number (ISSN)

1042-1122

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2005 John Wiley & Sons, All rights reserved.

Publication Date

01 Jan 2005

Link to Full Text

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