Abstract
The anodic dissolution of API X70 pipeline grade steel was investigated after different exposure periods of time and different temperatures in 1.0 M H2SO4 pickling solutions using optical microscopy, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization measurements. The EIS and polarization measurements showed clearly that the increase of immersion time increases the anodic and cathodic currents and corrosion current density decreased both the solution and polarization resistances for the steel in the sulfuric acid solution. It was also found that increasing the solution temperature in the range from 20 degrees C to 60 degrees C highly increased the corrosion of the API X70 pipeline steel due to the faster and contentious dissolution of X70 steel with temperature. Results together were in good agreement with each other confirming that X70 steel suffers sever corrosion in H2SO4 solution and that effect increases with increasing the exposure period and temperature.