Mechanism of inhibition of galvanic corrosion between carbon steel and stainless steel by sodium N-lauroyl sarcosinate and zinc sulfate

Inhibition effect of sodium N-lauroyl sarcosinate and zinc sulfate on the galvanic corrosion between carbon steel and stainless steel in 1% NaCl solution was investigated. The results of electrochemical measurements revealed that anodic and cathodic inhibitors inhibited galvanic corrosion by reducing the potential difference between the electrodes in two different ways. The values of corrosion potential and corrosion resistance of carbon steel increased after adding sodium N-lauroyl sarcosinate. In contrast, corrosion potential of stainless steel was shifted to the more negative region after adding zinc sulfate. X-ray photoelectron spectroscopy and scanning electron microscopy were applied to investigate the chemical compositions and morphologies of the films.