Abstrait

Electrochemical behaviours of two carbon steels in a sulfuric acid solution after tensile plastic deformation

Patrice Berthod

Aferritic steel and a ferrito-pearlitic onewere subjected to different amounts of tensile strain deformation. Electrodes were prepared from more or less deformed tensile samples, after cutting favouring each of the two studied orientations versus the traction axis. For each of thema cyclic polarisation run was performed between the cathodic domain and the solvent wall in the anodic side. The behaviour in the active state was characterized using the beginning of the potential-increasing part of the curves, with determination of the corrosion potential and current according to the Tafel method. The other part of the curve was used to specify the conditions of passivation and the behaviour in the passive state. Results show that both the amount of plastic strain and the orientation versus the deformation direction influence the electrochemical behaviour of the steels. For example, corrosion current is higher if the plastic strain amount is higher and if the considered surface is perpendicular to axis.