Corrosion resistance of Al-alloying high Cr–ODS steels in stagnant lead–bismuth

Corrosion resistances of oxide dispersion strengthened ferritic steels containing 3.5 wt% Al and 14–17 wt% Cr were examined. Experiments were performed in stagnant lead–bismuth eutectic (LBE) containing 10−6 and 10−8 wt% oxygen at 550 and 650 °C. The maximum exposure duration was 5000 h. Observations of the cross-sections of exposed samples obtained by scanning electron microscopy and Auger electron spectroscopy suggested that a very thin Al oxide layer was formed continuously. The materials containing 3.5 wt% Al exhibited good corrosion resistance despite being exposed to 5000 h of LBE containing 10−6 wt% at 650 °C. Furthermore, a favourable influence of adding minor amount of Zr was detected after 5000 h exposure to LBE containing 10−8 wt% oxygen at 650 °C.