Corrosion of Austenitic Steels and Their Components in Uranium-Containing Chloride Melts

Abstract

The corrosion resistance of AISI 316L, 12Kh18N10T (analogue of AISI 321) austenitic stainless steels and their basic components (metallic iron, nickel, chromium, molybdenum) was investigated in the melts based on the NaCl-KCl equimolar mixture at 750 ºC. Austenitic stainless steels underwent high temperature sensitization, and it was shown that this phenomenon determined the intergranular type of the steel corrosion. It was demonstrated that the presence of uranium ions in the electrolyte intensified corrosion processes. Metallic molybdenum demonstrated the highest corrosion resistance among the construction materials studied.

Intergranular Attack of Low Carbon Steel in Molten Aluminum Chloride

“…69,70 Additionally, the presence of secondary phases and carbides at the grain boundaries is able to induce fast propagation of localized corrosion by forming microgalvanopores that exhibit a difference in electronegativity. 54,55,[63][64][65][66] These mechanistic explanations can find potential application in the present corrosion phenomenon. Materials analysis up to this point has established molybdenum carbide's presence at the grain boundaries.…”

“…Grain boundary corrosion mechanism of carbon steel in molten AlCl 3 .-In studies that focus on localized corrosion in molten chloride salts, it has been established that the corrosion phenomena are inherently electrochemical in nature. [63][64][65][66][67][68] Further research has identified through microstructure observations the role of oxygen and moisture in drastically increasing corrosion. 69,70 Additionally, the presence of secondary phases and carbides at the grain boundaries is able to induce fast propagation of localized corrosion by forming microgalvanopores that exhibit a difference in electronegativity.…”

Uranium Electrorefining in 3LiCl-2KCl Based Melts

“…Uranium trichloride was synthesized by reducing uranium tetrachloride with excess zinc followed by vacuum distillation of the reaction product. The synthesis and purification procedure was described in detail previously (17).…”

Corrosion of Metallic Materials in 3LiCl-2KCl and 3LiCl-2KCl-UCl3

“…Uranium containing melts based on 3LiCl-2KCl eutectic were prepared by dissolving the required amount of UCl 3 . Uranium trichloride was prepared according to the scheme described previously (9). To ensure that uranium remained in the melt as ions in the oxidation state +3, a piece of metallic uranium was also added into the melt during this stage.…”