Corrosion investigations of steels in flowing lead at 400°C and 550°C

Experiments were conducted in a liquid lead pumped loop at 400°C and 550°C to examine the corrosion behaviour of ferritic and austenitic steels. The aim of this work is to identify suitable structural containment materials for a lead cooled accelerator driven transmutation reactor (ADS). During exposure to liquid lead containing 3–4×10−5 wt% oxygen, protective oxide layers grow on the surface of each candidate alloy. The total thickness of the multiphase layers increases parabolically with increasing exposure time. After 3000 h, they reach a maximum of 50 μm on one ferritic steel (Optifer) and of 30–40 μm on electron pulse-treated austenitic steels. Austenites with an untreated surface develop oxide layers of just 1–2 μm thickness. In each case the oxide layers prevent the dissolution attack of liquid lead.