Effects of HCO^-₃ on Crevice Corrosion of X70 Pipeline Steel

The crevice corrosion behavior of X70 steel was studied in the Ku’erle simulated solution of various HCO-3 concentrations by using a wedge-shaped crevice model.The results showed:classical crevice corrosion theory was adequate for the solution system not only containing single ion but also including several ions.In this study,when crevice corrosion happened the self-corrosion potential decreased gradually from the opening side to bottom side,Cl- concentration of the solution increased and pH value decreased in the crevice.The different concentrations of HCO-3 had a distinct influence on crevice corrosion.