Corrosion behavior of Si-enriched steels for nuclear applications in liquid lead-bismuth

Kurata, Yuji

The compatibility of steels with lead-bismuth is one of critical issues to develop accelerator driven systems and lead-bismuth cooled reactors. It is expected that Si-enriched steels have good compatibility with lead-bismuth. Type 316SS with addition of 2.5 wt.% Si and Mod.9Cr-1Mo steel with addition of 1.5 wt.% Si were produced for the purpose of nuclear applications. In this presentation, the results of corrosion tests of these steels in liquid lead-bismuth are reported. Corrosion tests were conducted at 550C in lead-bismuth containing 2.510 wt.% of oxygen and in lead-bismuth containing 4.410 wt.% of oxygen. The additions of 2.5 wt.% Si to 316SS and 1.5 wt.% Si to T91 had the effect of reducing oxide film thickness in liquid lead-bismuth where oxygen concentrations were high. However, it was found that the formed oxide films didn't have enough protectiveness to prevent Ni dissolution and the penetration of Pb and Bi in liquid lead-bismuth containing 4.410 wt.% of oxygen.