Oxidation/Corrosion Behaviour of ODS Ferritic/Martensitic Steels in Pb Melt at Elevated Temperature

Abstract

Lead-based melts (Pb, Pb-Bi) are considered as candidate coolants and spallation neutron targets due to their excellent thermophysical and nuclear properties. However, the corrosion of structural materials remains a major issue. Oxide dispersion strengthened (ODS) ferritic/martensitic steels are considered for high temperature application for both fission and fusion reactor concepts. The oxidation/corrosion kinetics in a static oxygen-saturated Pb melt at temperature of 550°C as well as the morphology and composition of scales formed on ferritic/martensitic Fe-9Cr-1.5W and ferritic Fe-14Cr-1.5W ODS steels have been investigated. Both materials showed homogeneous multiple, dense scales that consisted of typical combination of Fe3O4as outer sublayer and (Fe,Cr)3O4as inner sublayer. A nonuniform growth of inner oxide sublayers into the metal matrix as well as a good adhesion to the metal substrate is observed. With the prolongation of exposure from 240 to 1000 h, observed scales grow from 35 µm to 45 µm for ODS Fe-9Cr steel and from 40 µm to 60 µm for ODS Fe-14Cr steel with the thinning rates of 0,22 and 0,31 mm/year correspondingly. The mechanism of scales formation is discussed.

Environmental degradation of structural materials in liquid lead- and lead-bismuth eutectic-cooled reactors

“…The basic LMC behaviour of ODS-FeCr F/M steels was found very similar to that of conventional chromium (Cr) steels [128][129][130][131], however, the finer-grained ODS steels exhibited some differences in their overall corrosion behaviour. Yeliseyeva et al [128] studied the corrosion behaviour of ODS Fe-9Cr-1.5W and Fe-14Cr-1.5W (Y 2 O 3 ) steels in liquid Pb at 500-650 • C. They found that the finegrained microstructure facilitated the formation of Cr-based oxide scales in oxygen-containing liquid Pb, due to the more abundant GBs acting as paths for fast Cr diffusion into the growing oxide scale, much like the effect of dislocation networks in cold-rolled F/M steels.…”

Effect of yttria addition on the microstructure and mechanical behavior of ODS ferritic alloys processed by High Energy Milling and Spark Plasma Sintering

“…has a higher affinity for oxygen when compared with Fe and other alloying elements (Yaskiv and Fedirko, 2014) so when these alloys are sintered at 1100 °C, a passive surface layer of Cr 2 O 3 is formed. The analysis also revealed the presence of elemental traces of Cr and W, as well as of the α-Fe phase.…”

Synthesis of ferritic ODS steel with different electric current in arc plasma sintering method

“…Oxide dispersion strengthened (ODS) ferritic steels is one of the promising structural materials candidates for fuel cladding in fission reactor [1] because of their excellent strength [2,3], irradiation resistance [4,5] and oxidation resistance [6,7]. Compared with Fe-Cr steels, ODS ferritic steel has higher strength due to oxide dispersant.…”