The effect of Sn addition and sulfide ion concentration on the corrosion behavior of Cu-35Zn in NaCl solution

Abstract

AbstractThis study investigates the corrosion behavior of Cu-35Zn brass with 0 and 5 wt.% of tin in NaCl solution with a mass concentration of 3.5% containing 0, 400 and 1200 ppm of sulfide ions. For the purpose of assessing the corrosion behavior, open circuit potential, linear polarization resistance, electrochemical impedance spectroscopy and potentiodynamic polarization studies were employed. The results of the study show that on increasing the S2−concentration, an increase in the corrosion rate of the samples was observed. Moreover, the addition of Sn to the alloy leads to an increase in the polarization resistance and electrochemical impedance of the alloy. The corrosion potential as well as the corrosion current density were calculated using the Tafel extrapolation method. Addition of S2−shiftsEcorrtowards more negative values and increasesicorr. The surface of the samples was studied using light optical microscopy and pits were mainly observed in the grain boundaries of the Cu-35Zn sample.