Characterisation of Corrosion Damage in T91/F91 steel exposed to Liquid Lead-Bismuth Eutectic

• DOI: 10.48550/arxiv.2302.03470
• Publication Date: 2023-01-01
• Authors: Mark Lapington; Minyi Zhang; Michael P. Moody; Wen Zhou; Michael P. Short; F. Hofmann
• Keywords: Lath; Penetration (warfare); Bismuth

T91 samples were exposed to static liquid lead-bismuth eutectic (LBE) at 700{\deg}C for 250-500 hours in either an oxidising or reducing environment. Corrosion damage was characterised using electron microscopy techniques, which identified networks of LBE intrusion beneath LBE-wetted surfaces. Under conditions these are uniformly distributed, while they appear patchier and deeper under conditions. The individual intrusions preferentially follow microstructural features, initially along prior-austenite grain boundaries, followed by penetration down martensite lath boundaries. Local depletion Cr observed within 4 {\mu}m the intersecting suggesting local dissolution as main corrosion mechanism.