Characterization and Corrosion Behavior of Arc Sprayed Al Coating for Offshore Applications Plain carbon steels are widely utilized in structures because of their suitable mechanical properties, good performance, and low cost. However, in some harsh environments such as salty atmosphere, corrosion of carbon steels becomes a major concern and limits their applications. An effective way to improve the corrosion resistance of steel is to use a protective coating on the surface. Organic coatings such as paints are widely used to protect steel structures against corrosion. In order to improve corrosion resistance of organic coatings, intermediate layers of metal coatings can be used. Amongst various types of thermal spray processes, twin wire arc spray is widely used for deposition anticorrosion coatings. This is due to its economical advantages and the high deposition rate. A very wide variety of metallic coatings are used to improve corrosion resistance of steels. The most commonly used metals for protection of steel against corrosion are anodic to substrate which eliminate the need for completely pinhole-free barrier. In The current study, aluminum coating was deposited on carbon steel by twin wire arc spraying. SEM micrographs showed that a well- adhered coating with low level of porosity and oxide content was successfully deposited. No visible microcracks were detected in the coating. Coatings adhesion was measured by ASTM C633 standard and it showed that the adhesion strength of the coatings was slightly higher than those reported by other researchers. To evaluate the corrosion behavior of the coatings, electrochemical impedance spectroscopy (EIS) were employed during long-time immersion in 3.5% NaCl solution. The as-coated samples were also subjected to a 1500-hour salt spray assay. Polarization tests indicated that the corrosion current density of the aluminum coating is much more than that for bulk aluminum. This behavior could be due to the penetration of the electrolyte through porosities, results in accelerating aluminum corrosion. EIS measurements showed that the corrosion performance of coatings is improved by increasing immersion time in 3.5% NaCl solution as well as exposure to saline mist. This could be due to plugging of pores by corrosion products which hinder further penetration of the electrolyte through the coating.The corrosion products formed on the surface of the coatings were evaluated by X-ray diffraction and confirmed oxide formation. Despite the fact that the corrosion performance of the coating was improved during long time immersion in NaCl solution and saline mist, oxide content of the coatings was increased results in decreasing the cohesion strength of coating. To study the effect of sealing process on the corrosion behavior of thermally sprayed coatings,