Role of oxidation on LME of T91 steel studied by small punch test

On the kinetics of LME for the ferritic–martensitic steel T91 immersed in liquid PbBi eutectic

“…This phenomenon may occur for specific load/environmental conditions and can give rise to fast, uncontrollable crack growth. In general, it appears [2] that two necessary conditions have to be reached to observe LME: (i) wetting by the liquid metal, i.e. intimate contact between the metal and the oxide-free surface, and (ii) sufficient stress levels which probably result in localised plastic deformation.…”

“…In general, it has been reported [3] that structural materials are most sensitive to LME in a range of temperatures close to the melting point of the LM. In particular, cases of LME sensitivity in LBE (T m = 125°C), with not specified oxygen contents, were reported for T91 (supplied by different producers) at 160°C [4], 300°C [5] and 350°C [2]. By several authors [6], [7] was observed 20-30% decrease of the fracture resistance of T91 steel in LBE at 200-300°C, though not accompanied by fully cleavage-like fracture.…”

Mechanical behavior of coated T91 steel in contact with lead–bismuth liquid alloy at 300°C

“…The influence of liquid metal on mechanical properties of materials depends on different parameters: the liquid metal/solid metal couple, the yield strength of the material, stress concentrations, a direct contact between the material and the liquid metal [1,2,4,7,13,20]. Thus, the harder materials are generally more severely influenced by liquid metal [7,20].…”

“…At higher oxygen concentrations, oxide layer is formed [11] and decreases the fatal impact of LBE on the mechanical properties of the T91 steel [12]. Generally, the effect of liquid metal on the mechanical properties of materials is indeed connected to a direct contact (without oxide layer) between the material and the liquid metal [1,2,4,7,13]. So the formation of an oxide layer on the surface of the T91 steel in contact with LBE would appear as a means to limit not only the corrosion of the steel by the metal liquid but also the decrease of mechanical properties more particularly the fatigue resistance [12].…”

An approach to quantifying the chemical conditions necessary to form a magnetite layer on steels in lead and lead–bismuth eutectic

“…Lead-based coolants are especially attractive for use in accelerator-driven systems (ADS) as they can be used as a combined spallation neutron source and coolant. The major technological hurdles for the widespread adoption of lead-cooled fast reactor (LFR) technology are the problems of high temperature corrosion of structural materials, liquid metal embrittlement (LME) [23][24][25][26][27] and liquid metal enhanced creep (LMC) [28].…”