Corrosion behavior of Hastelloy alloys and stainless steel in the molten chloride salt NaCl-CaCl₂-CeCl₃

ABSTRACT

Compatibility tests are carried out on Ni-based Hastelloy alloys and stainless steel under the influence of the molten chloride salt NaCl-CaCl₂-CeCl₃ to investigate the corrosion behavior of molten salts with structural materials. Weight change measurements before and after the reaction tests show that the Hastelloy alloys have better corrosion resistance than stainless steel. The effects of molten salt purification on the corrosion behavior in the Hastelloy alloys are explored. The composition of the reacting phases is identified from transmission electron microscopy analysis and the corrosion mode is homogeneous corrosion with Cr and Fe diffusion, followed by Mo and Ni elution.

KEYWORDS:

• Molten chloride salt
• corrosion
• Hastelloy alloy
• stainless steel
• molten salt reactors
• microstructural analysis

Acknowledgments

This study was commissioned by the Japan Atomic Energy Agency as a part of the program of ‘Supporting the Development of Innovative Nuclear Technology to Meet Society’s Needs’ of Ministry of Economy, Trade and Industry in FY 2021–2022.

Disclosure statement

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

Additional information

Funding

The work was supported by the Ministry of Economy, Trade and Industry.