A comparative study on the passivation and localized corrosion of α, β, and α + β brass in borate buffer solutions containing sodium chloride—I. Electrochemical data

Authors
Morales, Jose Carlos; Fernández, Guillermina T.; Esparza, Pedro; González, Sergio G.; Salvarezza, Roberto Carlos; Arvia, Alejandro Jorge
Publication Year
1995
Language
English
Format
article
Status
Published version
Description
The passivation and localized corrosion of α-, β-, and (α + β)-brass in borate-boric acid buffer solutions (pH 9) containing different NaCl concentrations (cNaCl) were studied comparatively using conventional electrochemical techniques at 25 °C. The passivation of brass in borate-boric acid buffer was due to the electroformation of a complex passive layer consisting of ZnO · xH2O and Cu2O—CuO. In NaCl-containing borate-boric acid buffer the breakdown of the passive layer occurs leading to pitting corrosion when the applied potential exceeds a certain critical value, Eb. For a given type of brass, the value of Eb is shifted negatively as cNaCl is increased. At a constant cNaCl the localized corrosion resistance of brass increases in the following order (α + β)-brass ≅ β-brass < α-brass. For all brass the localized corrosion resistance was lower than that of polycrystalline Cu, but considerably greater than that of polycrystalline Zn. Passive film composition and de-alloying can account for the localized corrosion resistance of these alloys.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
Facultad de Ciencias Exactas
Subject
Ciencias Exactas
Química
Access level
Open access
License
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
Repository
SEDICI (UNLP)
Institution
Universidad Nacional de La Plata
OAI Identifier
oai:sedici.unlp.edu.ar:10915/80404