Influence of inhibitors on corrosion processes in naval steel/adhesive plastic tape/artificial sea water system

Abstract

A comparison was made of the influence of three different organic inhibitors (thiourea, benzotriazole, and 2-mercapto-benzothiazole) in preventing localized corrosion developed in mechanical failures and overlappings of protective plastic adhesive tapes applied on steel. Each of the inhibitors employed was incorporated into the adhesive of the system tested. Measurements of impedance and corrosion potential were made as a function of immersion time (up to 283 days) in artificial sea water. A visual inspection was also made of the metallic substrate after detachment of the plastic coating at the end of the experiment. A system without inhibitors was employed as reference. The use of 2-mercapto-benzothiazole as an inhibitor, at a concentration of 100 ppm incorporated in the adhesive, is recommended.