Corrosion behaviour of low activation steels in flowing Pb–17Li

The aim of this work is focused on the understanding of the corrosion mechanism of potential structural materials with the eutectic Pb–17Li melt. Therefore, long-term exposure tests have been made on the steels MANET I, F82H-mod. and Optifer IVa in the forced convection Pb–17Li loop PICOLO up to 10 000 h. It was found that two processes are responsible for the corrosive attack: firstly, the dissolution of the oxide scale during the so-called incubation period, which is dependent on temperature and flow velocity of the melt. Secondly, the main corrosion attack consists of a strong depletion of Fe from the steel resulting in a porous low adherent layer on the surface of the steels in which Pb–17Li could penetrate easily. Unfortunately this layer has no capability of protecting the steel from further corrosion attack but is eroded away by the flowing eutectic melt.