Corrosion behavior of austenitic steels in liquid lead bismuth containing 10−6 wt% and 10−8 wt% oxygen at 400-500 °C

Three austenitic steels (316L, DIN 1.4970 tube and rod material) were tested up to 5000 h at temperatures between 400 and 500 °C in PbBi containing 10−8 wt% oxygen and at 450 °C and 500 °C in PbBi with 10−6 wt% oxygen. Protective scales grown on the surface up to 450 °C consist mainly of Cr rich oxides. However, after 5000 h at 500 °C dissolution attack occurred. At 10−6 wt% and 450 °C the thin Cr rich oxide scale is interrupted by areas with a thicker duplex-layered oxide of magnetite and spinel. At the higher temperature of 500 °C the whole surface is covered by the duplex-layered oxide scale.