Fig. 1. Solubility curves of metal elements in liquid lead bismuth eutectic (LBE)^[1] (color online)

Fig. 2. Gibbs free energy-temperature diagram of oxides for steel exposed to liquid LBE (color online)

Fig. 3. Cross-section morphologies of typical oxide films on T91 steel under different oxygen concentrations after 1 000 h exposure in liquid LBE at 550 ^oC^[13](a) Saturated oxygen, (b) 1.26×10^-6%, (c) 1.41×10^-8%, (d) 1.12×10^-9%

Fig. 4. Cross section morphologies of 9Cr ferritic/martensitic steel after exposed to 10^-6% oxygen-controlled LBE at 600 ℃^[31](a) 1.0Si (1 000 h), (b) 0Si (2 000 h), (c) 0.7Si (2 000 h), (d) 1.0Si (2 000 h)

Fig. 5. Temperature dependent total elongation of T91 and SIMP steel tested in argon or LBE^[37-38]

Fig. 6. Fatigue data of T91 steel in liquid LBE^[45-48](a) Strain amplitude vs. fatigue life at 350 ℃, (b) Temperature vs. fatigue life, Strain rate vs. fatigue life at 350 ℃ (c) and 550 ℃ (d)

Fig. 7. (a) SEM-BSE image and EDS elemental distributions of the oxide scale on the 2 000 h exposure 316L specimen, (b, c) the corresponding BC and IPF maps at a specimen tilt of 70°^[63]

Fig. 8. APT analysis of the dual-phase structure in inner oxide layer of Si-enhanced stainless steel after exposure to oxygen-saturated LBE for 1 000 h^[70] (color online)(a) BSE image showing the location of APT samples, (b, c) BSE and SEM image of APT needle-like sample, (d) O, Ni, and Si atoms mappings, and (e) the proximity histogram across the interface of Fe-Cr spinel/(Fe, Ni)-rich phase based on an iso-concentration surface of about 22% (atomic percentage) Ni in Fig.(d)

Fig. 9. HAADF-STEM image and corresponding EDS elemental distributions of cross section in 14Ni steel after exposed in LBE (1.8 m∙s^-1, 5×10^-7%~5×10^-6%) at 550 ℃ for 4 008 h^[77] (color online)

Fig. 10. Correlation of fatigue lives of 316LN SS with strain amplitude in liquid LBE and in air at 400 ℃^[86]

Fig. 11. The quasi-cleavage cracking fracture morphology of T91 steel in saturated oxygen liquid LBE at 350 ℃^[46,59](a) Low-cycle fatigue, (b) Fatigue crack propagation

Fig. 12. (a, b) HAADF images of the segregation-induced ordered Pb/Bi-Fe superstructures and Pb-Bi clusters discontinuously distributed at the GB1 and GB2 at 350 ℃, (c) High magnification HAADF image at GB1, (d) Atomic super EDS mappings in Fig.(c)^[59] (color online)

Fig. 13. STEM observation of the grain boundary and Pb-Bi precipitates ahead of the crack tip for 316LN AuSS fatigue crack propagation tested at 400 ℃ of liquid LBE^[90] (color online) (a) HAADF images of the Pb-Bi precipitate at the grain boundary, (b, c) Interfacial cracking along twin boudaries, (d) Phase identification of the Pb-Bi cluster, (e, f) The Pb-Bi particle was embedded at twin boudaries