Erosion-corrosion resistance of Reduced Activation Ferritic-Martensitic steels exposed to flowing liquid Lithium

Abstract

In the framework of the IFMIF (International Fusion Materials Irradiation Facility) project, a lab scale plant named Lifus 6, designed and constructed in ENEA Brasimone Centre (Italy), has been employed for the evaluation of the resistance of Reduced Activation Ferritic-Martensitic (RAFM) steels to the erosion-corrosion mechanism exerted by flowing liquid Lithium. In this experimental campaign, Eurofer 97 and F82H specimens have been subjected to three different tests, defined by a Lithium temperature of 330 °C, a Nitrogen concentration in Lithium ≤30 wt ppm, a Lithium speed on the specimens surface of 15 m/s and by a duration respectively of 1222, 2000 and 4000 h. The assessment of the tests outcome has been made on the basis of the registered mass variation of each specimen, as well as its roughness alteration and its metallographic and compositional investigation. The analyses indicate the good resistance behavior of both the materials, which are characterized by corrosion rates <0.2 μm/year, very few and isolated corrosion items and only a small Chromium and Tungsten depletion in the alloy composition at the surface.