Effect of flow rate on electrochemical characteristics of marine material under seawater environment

As interest in the ocean for energy supply increases in various countries around the world, the shipbuilding and offshore industries are showing sharp growth trends. The harbor and offshore structures made of steel piles or sheet piles as components are easily to be corroded because oxygen is smoothly supplied through the thin water films formed by seawater splash. In particular, the supply of dissolved oxygen becomes easier and reaction rate is enhanced as the flow rate increases; as a result, corrosion rates increase. In addition, in marine environments, the seawater flows resulting from the difference between the rise and fall of the tides and ocean currents caused by topographical effects affect the corrosion characteristics of offshore structures. Therefore, in the present study, flow fields were analyzed in the seawater environments through particle image velocimetry (PIV) measurement; the electrochemical characteristics of S355ML steel were evaluated and the corrosion trend of this steel with changes in flow rate was analyzed as well. The results exhibited greater damage as flow rate increased due to the effects of corrosion and physical erosion.