Purpose – The aim of this paper was to clarify the influence of tensile stress on the electrochemical behavior of X80 steel in a simulated acid soil solution and attempt to understand mechanistic aspects of the corrosion behaviors of X80 under these conditions. Design/methodology/approach – The electrochemical behavior of X80 steel at various tensile stresses was investigated in a simulated acid soil solution using electrochemical impedance spectroscopy, potentiodynamic scan measurements and surface analysis techniques. Findings – The results show that as tensile stress was increased, the open-circuit potential decreased, the reaction activity increase, the reaction resistance (Rct)value became smaller by degrees, the corrosion product film resistance (Rf) first decreased and then increased and polarization current densities changed conversely. The corrosion product film was compact and continuous under the low stress, whereas it was relatively loose under high-stress conditions. Tensile stress promotes the movement of dislocations, which become active points when they move to the steel surface. The increase in the number of active points enhances the anodic dissolution rate and promotes the formation of corrosion product film whose blocking effect can decrease the dissolution rate. The corrosion rate of the specimen is determined by these two effects. Originality/value – This research provides an essential insight into the mechanism of the electrochemical behavior of X80 steel in acid soil environments.
Anti-Corrosion Methods and Materials – Emerald Publishing
Published: Mar 2, 2015