Corrosion in Heavy Liquid Metals for Energy Systems: Materials Compatibility with Liquid Metal Coolants I
Sponsored by: TMS Structural Materials Division, TMS: Corrosion and Environmental Effects Committee, TMS: Nuclear Materials Committee
Program Organizers: Osman Anderoglu, University of New Mexico; Alessandro Marino, Belgian Nuclear Research Centre; Michael Short, Massachusetts Institute of Technology; Peter Hosemann, University of California, Berkeley; Mike Ickes, Westinghouse Electric Company
Monday 8:30 AM
March 15, 2021
Room: RM 20
Location: TMS2021 Virtual
Session Chair: Alessandro Marino, SCK-CEN; Michael Short, MIT
8:30 AM
Material Needs and Developments for the Westinghouse Lead Fast Reactor: Mike Ickes1; Arash Parsi1; Luke Czerniak1; Paolo Ferroni1; 1Westinghouse Electric Company
Westinghouse is actively developing a Lead Fast Reactor (LFR), chosen due to the inherent safety and economic potential achievable with this Generation IV reactor type. Critical activities supporting the reactor design and development are materials testing efforts within Westinghouse and at national laboratories and universities worldwide. An overview of the Westinghouse LFR design will be given with an emphasis on aspects critical to materials performance. The Westinghouse-led materials testing efforts being performed in liquid lead will be reviewed and the available results will be summarized. These efforts include exploring the development of new materials while also investigating the use of commercially mature materials. Future activities in materials testing will also be briefly discussed.
8:50 AM Invited
Compatibility of Alumina-forming Austenitic Steels in Static and Flowing Pb: Bruce Pint1; Jiheon Jun1; Michael Brady1; Yuki Yamamoto1; Michael Ickes2; 1Oak Ridge National Laboratory; 2Westinghouse Electric Company
With renewed interest in Pb-cooled reactors, new compositions of alumina-forming austenitic (AFA) steels were selected for evaluation in static Pb at 500°-800°C and flowing Pb with a peak temperature of 650°C without pre-oxidation. Two general AFA classes were investigated, ~14Cr-(8-12)Ni-5Mn-2.3Al and 16Cr-25Ni-2Mn-3.8Al and compared to type 316H stainless steel. As expected, specimen mass loss increased with temperature after 1000 h exposures to Pb in sealed Mo capsules. The low Ni AFA samples showed lower mass loss at lower temperatures and the high Ni AFA showed less mass loss at 700°C, presumably due to easier alumina formation. Additional capsule experiments were conducted with Zr foil to getter oxygen, which generally reduced mass loss. Based on the capsule experiments, two AFA alloy compositions with 12Ni and 25Ni were selected for exposure in a thermal convection loop (TCL) constructed from pre-oxidized FeCrAlMo tubing. The TCL is assembled and results will be presented.
9:15 AM
Fundamental Interactions of Steels and Nickel-based Alloys with Lead-based Liquid Alloys or Liquid Tin: Carsten Schroer1; 1Karlsruhe Institute of Technology (KIT)
Application of lead-based liquid alloys or liquid tin to thermal energy conversion or storage opens the avenue to compact in design, highly efficient components in the high-temperature section of respective plants, however, at the cost of increased corrosion of metallic materials of construction, namely nickel-containing steels or nickel-based alloys. Experimental studies identify selective leaching of constituent parts, especially nickel, as an intermediate stage of complete dissolution, with the near-surface depletion zone originating in the solid alloys being dependent on the alloy composition, the liquid metal and temperature. If the oxygen content in the liquid allows, formation of solid oxides at least alters but may even suppress the leaching process, i.e. change the corrosion mode, just as intermetallic compounds forming in the presence of liquid tin. The observations evaluated with respect to fundamental mechanisms stem from experiments in lead-based alloys and liquid tin at 450–750 and 500–1000 °C, respectively.
9:35 AM Invited
Exposure Tests of Different Materials in Liquid Lead for LFRs: Effect of the Dissolved Oxygen on Corrosion: Serena Bassini1; Camillo Sartorio1; Andrea Antonelli1; Sebastiano Cataldo1; Angela Fiore1; Massimo Angiolini1; Daniele Martelli1; Micheal Ickes2; Paolo Ferroni2; Ivan Di Piazza1; Mariano Tarantino1; 1ENEA; 2Westinghouse Electric Company
Corrosion studies in high-temperature liquid Pb of conventional materials such as Fe-Cr and Fe-Cr-Ni steels for LFRs have demonstrated that they are prone to corrode affecting their structural integrity. Corrosion is minimized by using oxygen in Pb to form protective Fe-Cr oxide layer on steels, but its protectiveness well works only up to 450-480 °C limiting their applicability in LFRs. The present work shows preliminary corrosion results of new materials (Ni alloys, FeCrAl ODS, Zr and Mo alloys, and SiC) for potential use in Pb, obtained by ENEA and Westinghouse Electric Company. Tests were performed in static Pb at 550 and 750 °C and different oxygen concentrations. The results demonstrated the potential availability in Pb of some of these materials, and confirmed the key influence of oxygen on corrosion, imposing oxygen control in Pb coolant to prevent critical damage of materials. About oxygen control, some ENEA activities will be illustrated.
10:00 AM Invited
Corrosion of Refractory Metals and Advanced Steels in Lead-bismuth Eutectic: Stuart Maloy1; Keith Woloshun1; Eric Olivas1; Robert Wahlen2; Terry Grimm2; 1Los Alamos National Laboratory; 2Niowave Inc.
Lead and lead bismuth eutectic (LBE) are extremely corrosive at elevated temperatures (500-700°C) to conventional steels used in reactors. Flowing LBE introduces more challenges in terms of mechanical, thermal-hydraulics, and corrosion. To address these challenges, a high temperature corrosion test station was built at Niowave to test a variety of sample coupons in 500 °C flowing LBE for 1000 hours at high flow rates (>2 m/s). Several refractory materials and advanced alloys were tested and this presentation will address the evaluation of corrosion behavior of those samples. Initial results show promising corrosion resistance from refractory metals such as tantalum with significant degradation in the Fe-based alloys.
10:25 AM
Corrosion Investigations of Materials in Antimony-tin and Antimony-bismuth Alloys For Liquid Metal Batteries: Tianru Zhang1; Annette Heinzel1; Adrian Jianu1; Alfons Weisenburger1; Georg Müller1; 1Karlsruhe Institute of Technology
Liquid metal batteries are discussed as stationary electrical energy storage for renewable energies, in order to compensate their fluctuating supply of energy. A liquid metal battery consists of three different liquid, which stay segregated due to density differences and mutual immiscibility. The negative electrode is the low density liquid metal, in our case sodium, a medium density molten salt is the electrolyte and positive electrode is a high density liquid metal. For the latter Sb-Sn and Sn-Bi alloys are selected. However, one issue is the compatibility of the structural materials with the used liquids. In a first step the behaviour of potential structural materials in Sb3Sn7 and SbBi9 at temperatures between 370-450°C up to 750h were tested. The result showed that the corrosion in SbBi9 was significantly less than in Sb3Sn7 and the most promising materials were molybdenum and Max-phase coatings.
10:45 AM
Lead Bismuth Eutectic Corrosion on Austenitic Stainless Steel: Peter Hosemann1; Konstanza Lambrinou1; David Frazer1; Erich Stergar1; 1University of California Berkeley
Austenitic stainless steels are among the candidate alloys for Lead Bismuth Eutectic Cooled reactors. As with all steels it is essential that a specific oxygen level must be kept in order to form a passivation film. This work shows examples of low oxygen level and high oxygen level materials corrosion performance. TEM and STEM are deployed to reveal the effects LBE corrosion has on austenitic stainless steels. We find that leaching of Nickel into the LBE is observed under all circumstances and change the underlying material as much as the oxide layers formed. Furthermore, we find that grain boundaries, twin interfaces are presenting fast diffusion paths accelerating the materials degradations.
11:05 AM
Corrosion Behaviour and Microstructural Stability of Alumina-forming Austenitic Steels Exposed to Oxygen-containing Molten Lead: Annette Heinzel1; Adrian Jianu1; Alfons Weisenburger1; Hao Shi1; Renate Fetzer1; Georg Müller1; 1Karlsruher Institut of Technology
Lead and lead-based alloys are under consideration as working fluids for energy-related applications, such as advanced nuclear reactors, concentrated solar power and hydrogen production. However, their compatibility with Al-free structural steels (ferritic-martensitic and austenitic) causes considerable concerns. Alumina-forming austenitic steels, exhibiting high-temperature creep strength and oxidation resistance combined with a relatively low price, have a great potential to be used as structural materials for advanced energy systems.Therefore, model steels of FeCrAlNiX system (X: C, N, Nb, Y), were designed to form a protective alumina scale during exposure to oxygen-containing molten lead and to preserve the austenitic structure. The corrosion experiments were performed for up to 5000h, at 550-750°C temperature range in stagnant molten lead. The experimental results are presented and discussed in this communication.
11:25 AM
Liquid Metal Embrittlement of Al-containing High-entropy Alloys Exposed to Lead-bismuth Eutectic: Xing Gong1; 1Shenzhen University
The liquid metal embrittlement (LME) susceptibility of two Al-containing high entropy alloys (HEAs), i.e. fcc Al0.4CoCrFeNi and fcc+bcc Al0.7CoCrFeNi (at%), exposed to oxygen-enriched LBE at 350 and 500℃ was tested using slow strain rate tensile tests. The reference tests were done in Ar. The results show that the Al0.4CoCrFeNi alloy is not susceptible to embrittlement, while the Al0.7CoCrFeNi alloy is severely embrittled by LBE at both temperatures. The post-test microstructural examinations reveal that the LME cracks propagate either in the bcc phase or along the bcc/fcc phase boundaries. The phase boundary cracking becomes more prevailing at 500°C than at 350°C, likely resulting from enhanced grain boundary wetting or diffusion. It can be concluded, therefore, that the fcc phase is not susceptible to LME, while the bcc phase can be embrittled, and especially the bcc/fcc phase boundaries are weak points to be attacked by LBE at elevated temperature.