Investigation on Optimum Corrosion Protection Condition of S355ML Steel with Seawater Temperature

摘要

With increasing international recognition of ocean resources for a stable energy supply, the shipbuilding and offshore construction industries are growing rapidly. Since most offshore and harbor structures are constructed with steel pipe piles or sheet piles as structural components, there is always a heavy risk of corrosion due to the supply of oxygen to the thin water films formed by seawater splash. In particular, water temperature is one of the key factors affecting corrosion rate along with tidal current, dissolved oxygen, and concentration of salt. In this study, the corrosion-protection current and potential characteristics were evaluated to investigate the corrosion characteristics of the S355ML steel with water temperature variations in seawater environment. The result of the experiment indicated that the optimum corrosion protection current density was determined to be higher than 130 mA/m(2) at 5 degrees C, 190 mA/m(2) at 20 degrees C, and 250 mA/m(2) at 35 degrees C. Thus, it increased with the rising temperature of seawater.