An Investigation into High Temperature Water Corrosion on Reduced Activation Ferritic Martensitic Steel Eurofer 97

Abstract

The UK National Nuclear Laboratory (NNL) has been developing its capability in high-temperature water corrosion over the past years in collaboration with the University of Bristol, UK. Studies have been undertaken on nuclear fusion-specific material Eurofer-97, a reduced activation ferritic-martensitic steel. Eurofer-97 is a structural coolant-facing candidate material for the European DEMO water-cooled-lithium-lead breeder blanket design.

A microflow electrochemical cell assembly and Halbach array setup have been developed for use with the high-temperature water testing suite. The microflow cell assembly can provide in-situ electrochemical information on corrosion at increased flow velocities. The Halbach array allows experiments to be conducted to assess the impact of magnetic fields which are used for plasma confinement in DEMO. The effect of zinc addition is also investigated using the facility. For an insight into the effect of stress corrosion cracking, small-scale tensile specimens have been exposed to high-temperature (~300 °C) water.

NNL, in collaboration with the UK Atomic Energy Authority (UKAEA) and Lucideon Ltd, are to study the high-temperature water oxidation and environmentally-assisted cracking behaviour of Eurofer-97 as part of the EUROfusion programme. Presented are different experimental setups used to explore the aqueous corrosion of Eurofer-97 as well as preliminary information on the upcoming programme with UKAEA. and further developments planned for the facility.