Corrosion Science and Technology

The Corrosion Science Society of Korea (한국부식방식학회)
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Monitoring the Degradation Process of Inconel 600 and its Aluminide Coatings under Molten Sulfate Film with Thermal Cycles by Electrochemical Measurements

  • Take, S. (National Institute of Technology, Oyama College) ;
  • Yoshinaga, S. (National Institute of Technology, Oyama College) ;
  • Yanagita, M. (National Institute of Technology, Oyama College) ;
  • Itoi, Y. (National Institute of Technology, Oyama College)
  • Received : 2016.09.21
  • Accepted : 2016.11.27
  • Published : 2016.12.31
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Abstract

With a specially designed electrochemical cell, the changes in impedance behavior for Inconel 600 and aluminide diffusion coatings under molten sulfate film with thermal cycles (from $800^{\circ}C$ to $350^{\circ}C$) were monitored with electrochemical impedance measurements. It was found that corrosion resistance for both materials increased with lower temperatures. At the same time, the state of molten salt was also monitored successfully by measuring the changes in impedance at high frequency, which generally represents the resistance of molten salt itself. After two thermal cycles, both Inconel 600 and aluminide diffusion coatings showed excellent corrosion resistance. The results from SEM observation and EDS analysis correlated well with the results obtained by electrochemical impedance measurements. It is concluded that electrochemical impedance is very useful for monitoring the corrosion resistance of materials under molten salt film conditions even with thermal cycles.

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References

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