A STUDY ON PITTING CORROSION OF TIN-COATED INCONEL-600 BY IMMERSION TEST IN HIGH-TEMPERATURE CHLORIDE SOLUTIONS

Fitting corrosion of TiN-coated Inconel 600 was studied in chloride so lution at 200 degrees C. Stoichiometric polycrystalline TiN films were coated by the plasma-assisted chemical vapor deposition (PACVD) metho d at 500 degrees C. The TiN-coated and bare Inconel samples were immer sed in aerated CuCl2 solution at 200 degrees C. The density, maximum d epth, growth behavior and shape of the pits were determined at various chloride concentrations and immersion times. The TiN-coated Inconel s howed superior pitting resistance to that of the bare Inconel at low C uCl2 concentration, but the TiN film could not improve the pitting res istance of the Inconel substrate at high CuCl2 concentration.