Evaluation of Sea-air Interface Area Corrosion for Carbon Steel by WBE Technique and LP Technique

The corrosion of carbon steel in the sea-air interface area was studied by means of wire beam electrode (WBE), linear polarization (LP) technique, electrochemical impedance spectroscopy (EIS) and corrosion morphology. The WBE of carbon steel in the water-line area and under the waterline corroded seriously. The Icorr of the WBE in the two areas was the three-to ten-fold of that in the others areas. The Ecorr of the WBE in the air area was higher than that of the WBE in seawater area in the experimental period. The Ecorr of the WBE in the air area gradually lowered and the Ecorr of the WBE in the seawater area gradually increased. The corrosion product of WBE in the seawater was fluffy and had low adhesion. The corrosion product of WBE in the air was compact and had strong adhesion. The corrosion of carbon steel in the sea-air interface area is controlled by the potential difference, dissolved oxygen concentration and corrosion product.