%0 Journal Article
%T Oxidation/Corrosion Behaviour of ODS Ferritic/Martensitic Steels in Pb Melt at Elevated Temperature
%A O. I. Yaskiv
%A V. M. Fedirko
%J International Journal of Nuclear Energy
%D 2014
%R 10.1155/2014/657689
%X 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¡ãC 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 Fe3O4 as outer sublayer and (Fe,Cr)3O4 as 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£¿¦Ìm to 45£¿¦Ìm for ODS Fe-9Cr steel and from 40£¿¦Ìm to 60£¿¦Ìm 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. 1. Introduction Lead-based melts (Pb, Pb-Bi) are considered for use in Generation IV reactor coolant and spallation neutron targets due to their excellent thermophysical and nuclear properties [1]. The advantage of lead as a nuclear coolant is derived from its physical and chemical properties [2]. At the same time, the corrosion aggressiveness of lead melts with regard to the structural materials is one of the main issues of up-to-date reactor material science [3]. To make this system usable at high temperatures (above 500¡ãC), new classes of materials need to be developed and studied. Oxide dispersion strengthened (ODS) ferritic/martensitic steels are considered as candidate structure materials for high temperature application for both fission (Generation IV, Accelerator Driven Systems¡ªADS) and fusion reactor concepts [4, 5]. Their properties (high temperature strength and creep resistance) make them potentially usable for high temperature application in liquid metal cooled systems [6]. Although an application of ODS steels allows the working temperature limit to be increased up to about 700¡ãC, it is known that the corrosion aggressiveness of liquid metals regarding steels strongly depends on temperature; that is, the higher the temperature, the larger corrosion losses [7, 8]. In addition to the temperature, the specific phase-structural state of ODS steels, that is, presence
%U http://www.hindawi.com/journals/ijne/2014/657689/