Fretting corrosion in liquid lead of structural steels for lead-cooled nuclear systems: Preliminary study of the influence of temperature and time

The experiments revealed that protective oxide scales that formed on steels surfaces are removed by the fretting action. Thus, dissolution attack can take place. Besides, in the fretted areas, the formation of interposing layers was noticed. Such scales, created by debris retention and compaction, consist of an outer layer of oxidized debris and an inner layer of metallic debris. Due to the high Ni content, fretting corrosion affects more significantly the 1.4970 than the T91. Moreover after the 600 h test, fatigue cracking was observed on the 1.4970. The volume of material removed from the specimens by fretting corrosion, increased with temperature and time respectively number of cycles.