Performance of 9% Cr steels in flowing lead-bismuth eutectic at 450 and 550 °C, and 10−6 mass% dissolved oxygen

• Accelerated oxidation follows the formation of a thin, more protective oxide scale.
• Slight differences in Cr content are reflected by the oxidation rates at 450 °C.
• Microstructure of the steels seems more important for oxidation at 550 °C.
• Accumulation of liquid LBE at the oxide scale/steel interface may become decisive.

Ferritic–martensitic steels with, nominally, 9 mass% chromium (Cr) were exposed to flowing lead-bismuth eutectic (LBE) in the CORRIDA loop. The experiments were performed at 450° and 550 °C, at a concentration of dissolved oxygen of the order of 10−6 mass% and a flow velocity of 2 m/s. The maximum exposure time was 8000 and 20,000 h at 450° and 550 °C, respectively. Corrosion of these materials was analyzed both qualitatively and quantitatively. The steels generally show accelerated oxidation after initial formation of a thin, more protective oxide scale. At 450 °C, slight differences in Cr content are reflected by the determined oxidation rates, while, at 550 °C, the microstructure of the steels seems more important for oxidation behavior. However, processes following the accumulation of liquid LBE at the oxide scale/steel interface may, finally, become the determining factor of the overall performance.