Enhancement of corrosion resistance in thermal desalination plants by diamond like carbon coating

Abstract

Abstract The development of thermal desalination units is a suitable solution to tackle global water scarcity, especially for areas that have cheap energy. Stainless steel due to special properties, such as the durability and minimum maintenance requirement is a good choice for desalination plants. However, corrosion is the major problem with this material. Nevertheless, by selecting a thick enough and suitable cover, the corrosion resistance of the material greatly increases. To achieve this goal a thin layer of diamond like carbon (DLC) was deposited on the stainless steel 316 by Cathodic vacuum arc method and Raman spectroscopy was used in order to evaluate the quality of DLC layer. Subsequently electrochemical behavior of coated and uncoated substrates were studied and compared by using cyclic polarization test. It is found that current density and uniform corrosion rates of coated samples are far less than the uncoated sample even in different concentrations of sodium chloride solution and the DLC coating can increase uniform corrosion resistance.