Electrochemical measurements and corrosion characterization of steel in naphthenic acid solution at high temperature

Abstract

The corrosion behavior of a low carbon steel in simulated high temperature naphthenic acid environment has been investigated by the measurements of electrolyte conductivity, potentiodynamic polarization, and galvanic corrosion behavior test.The results indicate that the conductivity of naphthenic acid oil solution is in range of 0.003-0.008 ms/cm, which is far lower than that of pure water of 0.05 ms/cm. Besides, the paralleled polarization curve measured at the same condition shows different polarization behavior. The low solution conductivity and/or the difficulty in triggering the corrosion process by electrochemical manner may be responsible for this. Moreover, the galvanic corrosion test shows that the galvanic effect did not occur. Therefore, the naphthenic acid corrosion of steel is difficult to proceed at the manner of electrochemical mechanism but chemical mechanism.