Abstract
The corrosion of high strength steel after varied exposure periods of time, namely 30, 90 and 180 min immersion in 2.0 M H2SO4 pickling solution and its inhibition by 3-amino-5-mercapto-1,2,3-triazole (AMTA) were investigated. The study has been carried out using potentiodynamic polarization, electrochemical impedance spectroscopy and complemented by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyzer. It has been found that the increase of exposure period remarkably the corrosion of steel through increasing the anodic current, cathodic current, corrosion current density and corrosion rate. This effect also decreased both the solution and polarization resistances for the steel in the sulfuric acid solution. The presence of 1x10-3 M AMTA and the increase of its concentration to 5x10-3 M highly decreased the corrosion of the steel via the adsorption of AMTA molecules on its surface precluding its dissolution as was confirmed by the SEM micrographs and EDX profile analyses. Results together confirmed that the corrosion of steel increases with the increase of time and AMTA is a powerful corrosion inhibitor for the high strength steel in the 2.0 M H2SO4 pickling solutions.