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Advances in Materials Science and Engineering
Volume 2018, Article ID 3016304, 11 pages
https://doi.org/10.1155/2018/3016304
Research Article

Effect of Molybdenum on the Corrosion Behavior of High-Entropy Alloys CoCrFeNi2 and CoCrFeNi2Mo0.25 under Sodium Chloride Aqueous Conditions

1National Energy Technology Laboratory, 1450 Queen Ave. SW, Albany, OR 97321, USA
2ORISE, Oak Ridge, TN, USA
3U.S. Department of Energy, Washington, DC, USA
4AECOM, Los Angeles, CA, USA

Correspondence should be addressed to Joseph H. Tylczak; vog.eod.lten@kazclyt.hpesoj

Received 30 September 2017; Revised 14 December 2017; Accepted 21 January 2018; Published 20 March 2018

Academic Editor: Alicia E. Ares

Copyright © 2018 Alvaro A. Rodriguez et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The corrosion behavior of high-entropy alloys (HEAs) CoCrFeNi2 and CoCrFeNi2Mo0.25 was investigated in 3.5 wt. percent sodium chloride (NaCl) at 25°C by electrochemical methods. Their corrosion parameters were compared to those of HASTELLOY® C-276 (UNS N10276) and stainless steel 316L (UNS 31600) to assess the suitability of HEAs for potential industrial applications in NaCl simulating seawater type environments. The corrosion rates were calculated using corrosion current determined from electrochemical experiments for each of the alloys. In addition, potentiodynamic polarization measurements can indicate active, passive, and transpassive behavior of the metal as well as potential susceptibility to pitting corrosion. Cyclic voltammetry (CV) can confirm the alloy susceptibility to pitting corrosion. Electrochemical impedance spectroscopy (EIS) elucidates the corrosion mechanism under studied conditions. The results of the electrochemical experiments and scanning electron microscopy (SEM) analyses of the corroded surfaces revealed general corrosion on alloy CoCrFeNi2Mo0.25 and HASTELLOY C-276 and pitting corrosion on alloy CoCrFeNi2 and stainless steel 316L.