CORROSION OF INCONEL 600 ALLOY IN HIGH CONCENTRATED NaOH SOLUTION.

Polarization curves for the both specimens showed no change in electrochemical behavior in various corrosive environmental conditions at 50 degree C. However, the both specimens showed three peaks at higher temperatures than 50 degree C. The solution treated specimen showed a slightly low current density in the primary passive region and a slightly high current density in the secondary anodic peak, compared with those of the sensitized specimen. The films formed on the specimen surface during corrosion tests in 20M NaOH solution at 140 degree C were made of NiO, Cr//2O//3 and Fe//3O//4. The tests of crevice corrosion of I-600 and carbon steel (S15C) showed that general corrosion took place on the solution treated specimen, but the intergranular corrosion under the oxide films took place and it propagated to the crevice in the sensitized specimen.