Corrosion experiments of 9Cr-ODS steel were carried out in static Li at 873 K for 250 h and compared
with those of 9Cr-ODS in Pb–Li at the same exposure conditions. After exposure to liquid Li, 9Cr-ODS
showed slight weight loss and decrease in hardness near surface. The tensile property exhibited a negli-gible change at 973 K and the creep property degraded at 973 K. By metallurgical analyses, 9Cr-ODS dem-onstrated a non-uniform corrosion behavior by preferential grain boundary attack and pronounced
nodule-like morphology. The slight depletion of Cr was detected to about 15lm in depth by chemical
composition analyses. According to the calculation of free energy of formation, the nano-scale oxide par-ticles of TiO2in 9Cr-ODS were thermodynamically less stable while Y2O3were more stable compared
with those of Li2O in Li environment. However, Y2O3may be reacted with Li to form YLiO2. The mecha-nism of corrosion was proposed as the slight dissolution of Cr and Fe in matrix into liquid Li, chemical
interaction of nano-scale oxide particles with Li, preferential grain boundary attack and penetration of
Li, and finally development of extreme nodule-like structure during cleaning of Li. On the contrary,
9Cr-ODS showed much larger weight loss and depletion of Cr near surface but less marked corroded mor-phology in Pb–Li than in Li, which may be derived from higher solubility of Cr and Fe and lower activity of
Li in Pb–Li than in Li.
2013 Elsevier B.V. All rights reserved
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