Investigation of the effect of lead–bismuth eutectic on the fracture properties of T91 and 316L

Liquid metal embrittlement (LME) may decrease the mechanical integrity of the structure. Therefore quantification of the embrittlement effects by fracture mechanics assessment is highly needed for possible future licensing. Conventional fracture mechanics methods however cannot be applied to tests in liquid metal environment due to the opaque and conducting nature of lead–bismuth eutectic (LBE). Therefore new methods for assessment of plane strain fracture toughness in LBE were examined. The plane strain fracture toughness of T91 and 316L in liquid lead–bismuth environment at 200 and 300 °C is compared with the results obtained in air. The fracture toughness of T91 decreases in LBE while sufficient ductility remains, whereas the toughness of 316L is less affected.