[1L01-08] Liquid Metal Engineering in Fusion Reactor

[1L03] Experimental study on improvement of material compatibility by using corrosion inhibitor for liquid metal heat transfer mediums of A-FNS irradiation capsule

*Tatsuhiro Hosaka¹, Masatoshi Kondo¹, Masami Ando², Satoshi Sato² (1. Tokyo Tech, 2. QST)

Keywords:Corrosion inhibitor, Liquid lithium, Liquid sodium, Reduced-activation ferritic martensitic steel, Advanced fusion neutron source

Liquid metals Li and Na are candidate heat transfer mediums which are used in irradiation tests in A-FNS. The corrosion characteristics of reduced activation ferritic martensitic steel F82H in the liquid metals should be suppressed to clarify the effect of neutron irradiation on the material properties. The purpose of present study is to investigate the performance of Cr₃C₂ powder as corrosion inhibitor in the liquid metals. The corrosion tests of F82H in the liquid metals with and without Cr₃C₂ powder were conducted at 823 K up to 295 hours. The occurrence of corrosion along the boundaries of martensite microstructure in liquid Li was mitigated by the use of the corrosion inhibitor. The carbides precipitated along the boundaries did not chemically react with Li, since the chemical potential of carbon in liquid Li was appropriately adjusted by the addition of Cr₃C₂ powder. The oxidation corrosion in liquid Na was also mitigated by use of Cr₃C₂ powder due to the sacrificial reaction of Cr₃C₂ with oxygen dissolved in liquid Na. The corrosion in liquid Na was promoted due to low carbon potential by adding Mo plate in liquid Na.