Quantification of the Long-Term Performance of Steels T91 and 316L in Oxygen-Containing Flowing Lead-Bismuth Eutectic at 550°C

Abstract

The long-term performance of ferritic/martensitic steel T91 and austenitic 316L in oxygen-containing flowing lead-bismuth eutectic at 550°C was investigated by exposing the materials for up to 15000 h in the CORRIDA loop. The velocity of the liquid-metal flow was 2 m/s and the concentration of dissolved oxygen averaged 1.6×10−6 mass%. The resulting corrosion processes and products were analyzed and quantified using metallographic methods.

Environmental degradation of structural materials in liquid lead- and lead-bismuth eutectic-cooled reactors

“…The oxidation behaviour of AuSS was somewhat different from that of F/M steels [115,133,134]. The oxidation behaviour of this type of steels depended strongly on the exposure temperature.…”

“…Below the porous band, an IOZ layer formed (letter E). Generally, the growth of the IOZ layer was found to be independent of the total thickness of the three oxide scale sub-layers, and stopped after 2000 h of exposure [115], presumably due to the steel Cr depletion beneath the oxide scale. Layer F, located between the IOZ layer and steel substrate G, was depleted in Cr and O, as compared to the steel G and the IOZ layer E, respectively.…”

“…In some cases, the compact spinel oxide was penetrated by liquid LBE. Schroer et al [115] observed the LBE ingress through cracks and open porosity in the FeCr-spinel scale, which resulted in LBE infiltration of that scale. As the steel exposure continued, the IOZ disappeared (Fig.…”

Figure 9 from: Avdeenkov AV, Achakovsky OI, Ketlerov VV, Kumaev VYa, Orlov AI (2020) Basic models and approximation for the engineering description of the kinetics of the oxide layer of steel in a flow of heavy liquid metal coolant under various oxygen conditions. Nuclear Energy and Technology 6(3): 215-234. https://doi.org/10.3897/nucet.6.59068

“…It should be noted that the steel studied in sufficient detail for the structure of the oxide film does not give an unambiguous answer to the question of the presence or absence of an external layer of magnetite. But, in general, it can be argued that under nominal and similar modes, and in the case of dynamic experiments (coolant velocity 1-3 m/s)) (Zhang and Li 2007;Weisenburger et al 2008;Schroer et al 2009;Tsisar et al 2017), the magnetite layer is most likely absent due to erosion or dissolution of iron oxide films in the coolant. Although in some cases the same steels (for example, T91) show the presence of a layer of magnetite in dynamic experiments (Alekseev et al 2010a;Schroer et al 2012).…”

“…Kinetics of corrosion processes of steel components in HLMC is determined by the associated processes of hydrodynamics and the interaction of dissolved components, primarily such as oxygen and iron. The justification and appropriate modeling of these processes is an important component for substantiating heavy liquid metal coolant technology (Robertson et al 1988;Fazio et al 2001;Aiello et al 2004;Ivanov et al 2005Ivanov et al , 2017Zhang et al , 2007Lim et al 2010;Martinelli et al 2008a;Weisenburger 2008;Schroer and Konys 2009;Steiner 2009;Hwang and Lim 2010;Askhadullin et al 2011;Schroer et al 2012;Zhang 2013;Nuclear Energy Agency 2015;Tsisar et al 2017;Salaev et al 2018).…”