Effect of Multiple Film on the Tritium Permeation Property in 316L Stainless Steel

The films of TiN+TiC+TiN and TiN+TiC+SiO 2 were deposited on the surface of 316L stainless steel by physical vapor deposition technology. The characteristics of films are tested by SEM technology, it shows that the films are compact, thermal shock resistant, oxidation resistant and have good compatibility with bulk. The SIMS and IR analysis results show that the tritium permeation barrier is formed when TiC and SiO 2 films are annealed in hydrogen above 300 ℃. The tritium permeability in 316L with film is measured at various temperature, the results show that the tritium permeability in 316L with TiN+TiC+SiO 2 film is 4～6 orders of magnitude lower, and that in 316L with TiN+TiC+TiN film is 4～5 orders of magnitude lower than that in 316L with Pd film at about 200～600 ℃. These films may be used as the surface coating of the first wall, tritium blanket and heat exchanger in fusion reactor.