Corrosion behaviour of welds and Ta in liquid lead

Additionally, Ta, discussed as a pump impeller material, was exposed to Pb and PbBi at different temperatures (400-900 °C) and oxygen concentrations in liquid metal (saturated, 10−6 wt%, 10−8 wt% and reduced (<<10−8 wt%). Only the Ta specimens exposed to Pb with highly reduced oxygen content showed nearly no attack. All the others exhibited oxide scale formation that becomes severe above 400 °C test temperature.