The influence of sodium dodecyl benzene sulfonate (SDBS) on the corrosion behaviour of an elaborated annealed Fe-1Ti-20C alloy presenting a cementite phase (Fe3C), has been investigated in 0.5 M H2SO4 solution using electrochemical techniques. The results showed that this anionic surfactant inhibits the sulfuric acid corrosion of the ternary alloy. The inhibition occurs through adsorption of the surfactant on the metal surface without modifying the mechanism of corrosion process. The studied surfactant acts predominately as cathodic inhibitor by blocking effect on the cementite cathodic sites. The inhibition efficiency increases with increasing surfactant concentrations and decreases with increasing temperature. Maximum inhibition is observed at concentration above its critical micelle concentration (CMC). Temkin adsorption isotherm fits well with the experimental data. (c) 2008 Elsevier B.V. All rights reserved.