Corrosion inhibition by anionic surfactants of AA2198 Li-containing aluminium alloy in chloride solutions

This paper evaluates the inhibiting action of some anionic surfactants towards AA2198 corrosion in NaCl solutions; the effect of surfactant concentration in relation to chloride amount was determined. On separate electrodes, polarization curves were recorded after 1, 24 and 168 h immersion in the aggressive media, while EIS technique continuously monitored the alloy corrosion process. In general, these substances stifled both the cathodic and anodic processes and noticeably shifted the pitting potential (breakdown potential, EBR) in the positive direction. The most efficient compounds were N-lauroylsarcosine sodium salt and sodium dodecyl-benzenesulfonate, able to withstand the effects of 0.1 M Cl-.