PITTING RESISTANCE AND MECHANISM OF TIN-COATED INCONEL-600 IN 100-DEGREES-C NACL SOLUTION

Abstract

TiN films were deposited on Inconel 600 by PACVD method using a gaseous mixture of TiCl4, N-2, H-2 and Ar, and their pitting resistance and mechanism in 100 degrees C NaCl solution were investigated. Anodic polarization measurement of TiN-coated Inconel 600 was compared with that of bare Inconel 600. TiN-coated Inconel 600 has a higher E(np) and a lower pit depth than bare Inconel 600. It also shows a smaller pit aspect ratio due to the concentration of the corrosion in the Inconel 600 contacted with the TiN film. When the Inconel 600 has a rough surface, E(np) decreases and the pit density increases to a great extent. However, E(corr), pit depth and pit aspect ratio are not affected.