ENVIRONMENTAL FACTORS AFFECTING CORROSION OF SABIC MILD STEEL IN ACID CHLORIDE SOLUTIONS

The corrosion behavior of Sabic mild steel in HCl solutions was studied under different environmental factors such as acid concentration, solution temperature and state, using weight loss, open – circuit potential, EIS and potentiodynamic polarization measurements, and optical microscopy. The rate of corrosion increases with increasing acid concentration, solution temperature and immersion time. Also, the corrosion process is affected by polarization than open-circuit conditions, i.e. accelerate the corrosion process. The mechanistic sequences of each of the cathodic and anodic electrochemical processes are uninfluenced with acid concentration and temperature but their rates are increased with increasing both factors. Also, the solution states showed nearly a minor effect on the corrosion process. The activation energy is calculated and equal ≈ 57.4 kJ/mol. The SEM studies showed pits along the oxide film formed on the surface as a result of corrosive action of ions, its number and propagation depend on acid concentration and solution temperature.