Abstract

The corrosion and passivation of tin in sodium borate (Na2B4O7) solutions at pH = 8.35 were studied by potentiodynamic and cyclic voltammetry techniques. The effect of the following factors on the anodic dissolution and passivation of tin metal are discussed: concentration of borate ion, pH, potential scan rate, successive cyclic voltammetry, switching potential and progressive additions of halide ions. The primary passivation is attained when the metal is covered with a film of Sn(OH)2 and/or SnO. Permanent passivity occurs when Sn(OH)4 and/or SnO2 forms a continuous layer on the electrode surface. The anodic dissolution reactions are controlled by diffusion. In all experiments, the aggressive action of the halides decreased in the order Cl− > Br−. SEM examination confirms the occurrence of pitting corrosion in presence of halide ions. The pitting potential (Epit) decreases with increasing halide concentration.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.