Carburization of metals by a chemical mechanism of carbon transport through molten fluoride salts

JOURNAL OF NUCLEAR MATERIALS

卷:539

Article

Chan, Kevin J.¹  Singh, Preet M.¹ 

[1] Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA

关键词: Molten salt;    Carburization;    Corrosion;    Carbide;   

DOI  :  10.1016/j.jnucmat.2020.152307

来源: Elsevier

【 摘 要 】

Carburization of structural alloys used in Fluoride Cooled High Temperature Reactors (FHR) can result from the interaction between the metal and graphite components and cause changes in alloy properties. However, carburization requires transport of carbon from graphite to alloy surfaces through the molten fluoride coolant. This work introduces an alternative to previously proposed carbon transport mechanisms. The new mechanism is based on the generation of carbonate ions (CO32-) by oxide impurities in the salt reacting with graphite. CO32- is then reduced on metal surfaces to deposit carbon. This work demonstrates the reduction of dissolved CO32- on pure Fe, Ni, Cr, Mo, and W surfaces without an applied potential in molten FLiNaK at 700 degrees C. We also demonstrate that the interaction between oxide and graphite in molten FLiNaK media produces CO32-. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

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