1989 年 38 巻 9 号 p. 480-484
A study was made of the effect of addition of NO3- ions on the corrosion of titanium in HCl solutions. For titanium, NO3- ions was necessary to add at least 0.008kmol·m-3 (0.05mass%) to achieve corrosion inhibition in HCl solutions. Above this concentration, titanium passivates, and hydrogen pick up by titanium was also prevented. Ti3+ ions near surface seem to be quickly oxidized by NO2 formed with other products in the reduction of NO3- to Ti4+ in the reaction Ti3++NO2→Ti4++NO2-. As a result, titanium passivates and corrosion inhibition of titanium is achieved.