Developing Procedures for Fracture Toughness Tests in Lead-bismuth Eutectic

T91 ferritic-martensitic steel is one of the candidate materials to future fast reactors where lead-bismuth eutectic (LBE) is chosen as the coolant. The interaction of the steel with LBE coolant should be investigated by means of mechanical tests and detailed microstructural analysis. Quantitative analysis requires fracture toughness tests in LBE. However tests in LBE are not easily applied with conventional methods due to the conductive nature of LBE. In addition, there are no standards or guidelines for fracture toughness tests in LBE. In this work fracture toughness tests in inert environment and LBE are compared and technical problems encountered during tests in LBE are discussed.