Corrosion Control of Steel Pipe for Water System in Coastal Power Plant

To control the corrosion of water pipes in a coastal power plant, the difference of corrosion performance for carbon steel in seawater and seawater reverse osmosis (SWRO) water was investigated comparatively by means of weight-loss test, scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical measurement. The results showed that the rust layer formed in seawater had a protective effect on iron by hindering the transfer of dissolved oxygen; but that formed in SWRO water could accelerate iron corrosion by providing a larger cathodic area. In practice, SWRO water showed more corrosive to carbon steel than seawater. Remineralization is a good choice for the post-treatment of SWRO water. Besides, corrosion resistant materials such as stainless steel and lined steel pipe could be designed to replace carbon steel as the material for SWRO water pipe.