Corrosion Prevention of Type 316L Stainless Steel in Pb-17Li Through Nickel Addition

In order to investigate the effect of nickel saturation on the corrosion of Type 316L stainless steel (SS 316L) by Pb-17Li, a SS 316L test capsule was fabricated and filled with Pb-17Li along with some Ni chunks. The system was maintained at a temperature gradient of 923 to 623 K for 3200 h. Characterization of SS 316L tube samples from various temperature locations by an electron probe microanalyzer revealed that dissolution of Ni from the steel matrix could be effectively suppressed in this manner, though leaching of Cr and Fe could not be prevented. No nickel depletion from SS 316L was observed in the tube at the higher temperature (923 K), even after 3200 h, whereas nickel encrustations were found in low-temperature areas. The saturation of Pb-17Li by the added nickel had possibly prevented Ni dissolution from the SS 316L surface, and thereby, the formation of a porous corroded layer could be avoided.