Behaviour of pre-stressed T91 and ODS steels exposed to liquid lead-bismuth eutectic

• Published in: Corrosion science Vol. 131; pp. 264 - 277
• Main Authors: Hojna, Anna, Hadraba, Hynek, Di Gabriele, Fosca, Husak, Roman
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01-02-2018; Elsevier BV
• Subjects: Bismuth; Crack initiation; Cracks; Dispersion hardening steels; Ferritic stainless steels; Heat resistant steels; Liquid lead; Liquid metal embrittlement; Microhardness; Oxidation; Oxygen content; Plastic deformation; Scanning electron microscopy; SEM; Steel; SEM; Oxidation; Steel; Liquid metal embrittlement
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2017.12.005

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•Bend specimens were exposed to liquid lead-bismuth at 350°C up to 2000h.•Thin protective oxide layers; continuous on T91 and discontinuous on the ODS steels.•T91: the inner oxidation zone was wavy under tension and straight without stress.•No tendency to oxide failure, no LME crack.
Structural materials compatibility in conditions relevant to plant operation is of primary importance to safety. The work describes the behaviour of T91 and ferritic ODS steels, 14%Cr and 19%Cr under such conditions. Three-point-bend specimens were pre-stressed up to yield strength, then exposed to flowing lead-bismuth eutectic in a loop at 350°C for 500 and 1000h, in non-flowing one for 2000h. The oxygen content was measured to be in the order of 10−5wt.%. Post-test examination by means of microhardness and SEM with EDS demonstrated the formation of thin oxides without crack initiation, which is discussed. Because it was not observed either direct contact between the steels and LBE or local high plastic deformation, no LME occurred.