Corrosion behaviours of Ni-Mo-Cr alloy and 316 stainless steel in molten NaCl-KCl-AlCl₃ salts at high temperature

ABSTRACT

The corrosion behaviours of Ni-Mo-Cr alloy and 316 stainless steel samples after immersing in NaCl-KCl-AlCl₃ salt at 400.0°C for 168 h were investigated. The surface of Ni-Mo-Cr alloy basically kept its pre-corrosion morphology, with only a few corrosion pits. While NaCl-KCl-AlCl₃ salt had stronger corrosivity to 316SS. After corrosion, the grain boundary of the surface of 316SS alloy was clearly visible, and the Fe and Cr atoms on the surface of 316SS were selectively corroded, leaving a Ni- rich layer of about 6.5 µm on the outmost surface of 316SS. At the temperature of 400.0°C, the corrosion resistance of Ni-Mo-Cr alloy to molten NaCl-KCl-AlCl₃ salt was better than that of 316SS.

KEYWORDS:

• Molten salt
• corrosion
• Ni-Mo-Cr alloy
• 316 stainless steel
• morphology

Acknowledgement

Supported by the DNL Cooperation Fund, CAS (DNL202012).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All date included in this study are available upon request by contact with the corresponding author.

Additional information

Funding

This work was supported by the Dalian National Laboratory for Clean Energy (DNL) Cooperation Fund, Chinese Academy of Sciences, CAS [DNL202012].