Corrosion of EP823 Steel Cladding Under Heavy Liquid-Metal-Coolant Reactor Conditions: A Review

Abstract

The compatibility of structural materials with lead and lead-bismuth eutectic is a significant challenge in the development of fast neutron reactors with heavy liquid-metal coolants. Liquid-metal corrosion negatively affects ferritic-martensitic steel EP823-Sh. The mechanism of liquid-metal corrosion of steels corresponds to physicochemical dissolution when the oxygen content in lead is less than the equilibrium value. The selective dissolution of steel components from the surface of the claddings is observed. When the oxygen concentration exceeds the equilibrium value, the corrosion products are the outer oxide layer of magnetite and the chromium spinel of nonstoichiometric composition such as Fe(Fe_1-x,Cr_x)₂O₄, as well as the development of an internal oxidation zone along the grain boundaries, which also can be observed. The pure-lead heat transfer sublayer between the fuel and the cladding causes the dissolution and deposition of steel components on the inner surface of the cladding. To increase corrosion resistance, it is proposed to modify the surface using plasma and laser processing, as well as by applying protective coatings.

Keywords:

• Corrosion
• ferrite-martensitic steels
• EP823
• lead
• lead bismuth

Disclosure Statement

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

Data Availability Statement

All papers used for the state of the art are available in the open.

Author Contributions

Rafael Isayev: Methodology, conceptualization, visualization, formal analysis, writing original draft, and writing–review and editing. Natalia Pukhareva: Methodology, conceptualization, visualization, formal analysis, writing original draft, and writing–review and editing. Evgeniy Malinovskiy: Methodology, conceptualization, visualization, formal analysis, writing original draft, and writing–review and editing. Egor Korenevski: Formal analysis and writing–editing. Pavel Dzhumaev: Supervision, validation, and writing–review and editing.