[en] Liquid Pb and PbBi are among the promising coolants for reactors operating in fast neutron spectrum. Beside its excellent neutronic properties, Pb and PbBi offer improved safety features. But, deficient compatibility of structural materials with the liquid metals especially at higher temperatures is a major challenge to be solved for the use of Pb and PbBi cooled fast nuclear systems like MYRRHA, BREST and others at time under consideration. The major driving force for corrosion attack is the solubility of steel alloying elements like Ni, Fe and Cr in the HLM. Addition of oxygen to the HLM to provide in-situ formation of protective oxide scales is the mitigation mechanism of choice but limits the operating temperature window. Ferritic steels are not considered at present due to their susceptibility to liquid metal embrittlement. The use of austenitic steels of 316type is limited to temperatures below 450°C due to corrosion attack. Even at this temperature localized corrosion was observed at oxygen concentrations in the HLM of about 10^-7 wt%. Beside composition and crystal structure, imperfections like twin boundary seems to impact the compatibility of the steel in HLM. To enlarge the operation window of HLM cooled nuclear reactors advanced mitigation measures are under investigation since several years. Alumina forming surface alloyed layers and bulk materials are one option to increase the operating temperature window to 600°C by increasing the corrosion resistant in oxygen containing liquid metals. Fully corrosion resistant coatings like alumina, TiN or W are additional possible options, but require the integrity of the coating at all operating conditions, which is less stringent for the protection methods that rely on inoperation forming capabilities. (author)