The long-term corrosion performance of Alloy 22 in heated brine solutions

Journal Article · Fri Feb 13 00:00:00 EST 2015 · Corrosion

DOI:https://doi.org/10.5006/1581· OSTI ID:1333838

Enos, D. G. ^[1]; Bryan, C. R. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Long-term corrosion experiments have been performed on Alloy 22 (UNS N06022), in a series of heated brines formulated to represent evaporatively concentrated ground water, to evaluate the long-term corrosion performance of the material. These solutions included 0.5 M NaCl, in addition to two simulated concentrated ground water solutions. Under conditions where Alloy 22 was anticipated to be passive, the corrosion rate was found to be vanishingly small (i.e., below the resolution of the weight-loss technique used to quantify corrosion in this study). However, under low pH conditions where Alloy 22 was anticipated to be active, or more specifically, where the chromium oxide passive film was not thermodynamically stable, the corrosion rate was appreciable. Furthermore, under such conditions the corrosion rate was observed to be a strong function of temperature, with an activation energy of 72.9±1.8 kJ/mol. Time of Flight-Secondary Ion Mass Spectroscopy analysis of the oxide layer revealed that, while sulfur was present within the oxide for all test conditions, no accumulation was observed at or near the metal/oxide interface. Furthermore, these observations confirm that inhibition of passive film formation via sulfur accumulation does not occur during the corrosion of Alloy 22.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE), Fuel Cycle Technologies (NE-5)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1333838
• Report Number(s): SAND--2014-20152J; 547476
• Journal Information: Corrosion, Journal Name: Corrosion Journal Issue: 6 Vol. 71; ISSN 0010-9312
• Publisher: NACE International
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
general corrosion
mass loss
nickel alloys
nuclear waste