Inhibition effect of 1,2,4-triazole-5-thione derivative on the corrosion of brass in 3% NaCl solution

Corrosion inhibition of cu60zn40 alloy in aerated 3% nacl solution using 4-amino-3-methyl -1,2,4-triazole-5-thione (mtsnh) was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (eis). the surface analysis studies were carried out by scanning electron microscopy (sem). effect of immersion time on the efficiency of the corrosion inhibition process was studied. the inhibiting efficiency found to increase with increasing inhibitor concentrations and with increasing immersion time. the polarization curves indicate that mtsnh act as mixed type inhibitor retarding both anodic and cathodic reaction. the impedance results show a change the corrosion mechanism of brass in the presence of inhibitor. appropriate electric equivalent circuit model was used to calculate the impedance parameters. sem studies confirm the presence of protective mtsnh film on the alloy surface.