Effect of SO^2-₄ on Pitting Corrosion Behavior of X80 Pipeline Steel in NaHCO₃ Solution Containing Cl-

Effect of SO2-4 on the pitting corrosion behavior of X80 pipeline steel has been investigated in 0.5 mol/L NaHCO3 solution containing 0.01 mol/L NaCl by potentiodynamic polarization experiment,and the mechanism was discussed based on capacitance measurements technique.The potentiodynamic polarization curves showed that the values of pitting potential (Epit) reduced and number of pitting corrosion increased after adding SO2-4.The reason was the increase of defects due to the adsorption of SO2-4 on X80 steel surface,and the pitting initiation sites and occurrence probability were enhanced.