Investigation of corrosion behaviours of high level waste container materials in simulated groundwater in China

Abstract

Appropriate high level radioactive waste container materials in China are still under investigation. The corrosion behaviours of four types of materials (carbon steel Q235, aluminium alloy 2024, copper and stainless steel SUS 304) in simulated groundwater at room temperature were investigated. The corrosion rate was measured through the weight loss method. The chemical composition of corrosion product films formed on the surface of materials was investigated by means of X-ray diffraction and energy dispersive X-ray spectroscopy. The results showed that there was no crevice and pitting corrosion for carbon steel after one year of immersion; the corrosion was dominated by general corrosion, the composition of the corrosion product film being mainly γ-FeOOH, as well as Fe3O4. Copper underwent slight crevice corrosion, but aluminium alloy 2024 suffered serious localised corrosion. No corrosion was observed on stainless steel SUS 304. The presence of oxygen promoted crevice corrosion of copper and aluminium alloy 2024.