Compatibility of structural materials with lead and lead bismuth eutectic for CSP applications

Liquid metals are being proposed as Heat Transfer Fluid (HTF) for CSP applications due to their good thermal properties. However, the increase of the operating temperature regime and the high aggressiveness of liquid metals can aggravate the structural material degradation regarding to corrosion and embrittlement behavior. Liquid metal corrosion occurs mainly by the dissolution of the metallic elements into the liquid metal. At medium temperatures (450-500°C), structural alloys can be protected by the in-situ formation of protective oxide layers depending on the oxygen content. At elevated temperatures, the oxygen control is not effective and other protection strategies are necessary like the use of Oxide Dispersive Strengthened (ODS) steels. Long term corrosion tests have been performed in lead and LBE liquid metals with four different materials: martensitic T91 steel, austenitic AISI 316L stainless steel, 9CrODS and 12CrODS steels with different combinations of temperature, oxygen content and exposure times. At elevated temperatures (600°C and 700°C) the corrosion behaviour of ODS steels have been tested up to 10000 hours.