Electrochemical polarization studies of API 5L Grade X65 steel in chloride solution

Anodic and cathodic polarization measurements were carried out in 3. 5% NaCl solution on API 5L grade X65 steel commonly used for offshore structures. Tests were performed on a rotating disk electrode and both potentiodynamic and potentiostatic polarization methods were employed. An analytical expression for the polarization curve is proposed to describe boundary conditions on the cathode for current and potential distribution calculations. The parameters of this expression are discussed and obtained directly from experimental polarization curves.