CORROSION BEHAVIOUR OF INCONEL 617 COATED WITH SILICON OXIDES IN IMPURE HELIUM.

Inconel 617 samples were coated with silicon or silicon oxide SiO//x(0 less than X less than equivalent to Japanese. films by reactive magnetron sputtering. The coated samples were corrosion tested at 900 and 1000 degree C. The impure helium simulates the coolant gas of a high temperature gas cooled reactor. Silicon in the SiO//x films diffused into the substrate to form the carbide (Si,Mo)//x C//y. Nickel and chromium in the substrate diffused into the films to form silicides. The films exfoliated enhanced carburization. Stoichiometric SiO//2 films had excellent protective effects at 900 degree C. The protective effect degraded at 1000 degree C.