Oxidation behaviour of P122 and a 9Cr-2W ODS steel at 550C in oxygen-containing flowing lead-bismuth eutectic

Schroer, C.*; Konys, J.*; Furukawa, Tomohiro  ; Aoto, Kazumi 

The long-term performance of P122 and ODS steel was tested in oxygen-containing flowing lead-bismuth eutectic at 550 C and a flow velocity of 2 m/s by means of exposure experiments in the CORRIDA loop of FZK. The target for the enrichment of dissolved oxygen was a concentration, c, of 10mass%. Owing to initial problems in controlling c, some of the exposed specimens experienced varying conditions, which allowed for investigating the influence of temporarily low c (down to 10mass%), in addition to constantly high c (averaging 1.610mass%). Maximum exposure times at constantly high c were 10,000 and 20,000 h for P122 and the ODS steel, respectively. Under the testing conditions, both steels were affected by moderate oxidation resulting in the formation of a compact layer of a spinel-type oxide on the surface and a more or less pronounced internal oxidation zone. The thickness of the oxide scale was quantified and used for determining the material loss. For c = 10mass%, logarithmic and power rate laws were fitted to the obtained data as a basis for predicting the metal recession at times exceeding the experimental exposure times.