Stability of oxide layer formed on high-chromium steel in LBE under oxygen content and temperature fluctuation

Weisenburger, A.*; Aoto, Kazumi ; Mller, G.*; Heinzel, A.*; Furukawa, Tomohiro  

The behaviour of protective oxide layers on P122 and its welds and of ODS steel in LBE is examined under conditions of changing temperatures and oxygen concentrations. P122 teel (Cr) and its welded joints are exposed to LBE at 550 C for 4.000 h with oxygen concentrations of 10 and 10wt% which change every 800 h. It is found that like in case f constant oxygen concentration of 10 wt% a protective spinel layer was maintained on P122 and also on its welded joint. Two experiments are conducted on ODS steel, both with temperatures changing from 550 to 650 C and back every 800 h, one experiment with 10 the other with 10 wt% oxygen in LBE. Like in the former test with constant emperature at 550 C no dissolution attack could be observed in experiments with temperature fluctuation. Contrary to this results is the observed dissolution attack on ODS with a onstant temperature of 650 C at 10 wt% oxygen in which formation of a protective layer was not allowed before reaching 650 C LBE temperature.