AN ELECTROCHEMICAL AND SERS STUDY OF THE EFFECT OF -[N,N-BIS-(HYDROXYETHYL)AMINOMETHYL]-BENZOTRIAZOLE ON THE ACID CORROSION AND DEZINCIFICATION OF 60 40 BRASS/

The effect of -[N,N-bis-(hydroxyethyl)aminomethyl]-benzotriazole (BTLY ) on the corrosion and dezincification of a 60/40 brass in aqueous H2S O4 at 30 degrees C has been investigated by means of solution analysis , potentiodynamic and surface enhanced Raman scattering (SERS) techniq ues. Overall inhibition (for copper and zinc dissolution) increased wi th increasing concentration to a maximum (63.1%) at the 5 x 10(-4) M l evel. This was comparable to that observed for benzotriazole (BTAH) un der the same conditions. Solution analysis indicates that BTLY is inef fective in preventing dezincification. Polarization studies show that BTLY acts initially to suppress the cathodic and anodic corrosion reac tions. The SERS spectra suggest that the adsorption with copper in the brass occurs through nitrogen in the azole ring of the protonated mol ecule BTLYH.