الفهرس 
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Abstract
Year upon year the cost of marine corrosion has increased until it is estimated today at 4 % of the Gross National Product. Over the past decade large effort has been focused upon understanding the causes of marine corrosion and the way in which protective systems and more resistant materials can be used to reduce or entirely eliminate sea water corrosion problems. Many different types of destructive attack can occur to structures, ships and other equipment used in sea water service. The term ’aqueous corrosion’ describes the majority of the most troublesome problems encountered in contact with sea water. Aqueous corrosion requires a systematic approach to eliminate or manage them. It is an electrochemical process, and all metals and alloys when in contact with sea water have a specific electrical potential (or corrosion potential) at a specific level of sea water acidity or alkalinity - the pH. Sea water, by virtue of its chloride content, is a most efficient electrolyte. The presence of oxygen in marine atmospheres, sea sprays and splash zones at the water-line, and sometimes surprisingly at much greater depths, increases the aggressiveness of salt attack. The differential concentration of oxygen dissolved at the waterline or in a DROPlet of salt spray creates a cell in which attack is concentrated where the oxygen concentration is lowest. Crevices which allow ingress of water and chlorides but from which oxygen is excluded rapidly become anodic and acidic and are hidden start points of corrosion. One of the main methods for controlling the tendency of metals to corrode in sea water is by isolation of the corroding metal from the sea water by painting, or other coating. The present work is investigating three types of polymeric paint which are: Hempalin Enamel 52140, Hempadur Mastic 45880 and Hempadur Mastic 55210. Different standard tests were performed on the steel coated with the paints. These tests were: (1) adhesion/cohesion test (pull-off, Strength test) to evaluate the adhesion of paint to the steel substrate, (2) the X-Cut test, (3) the cross-cut test, (4) the salt-spray corrosion test and (5) the corrosion TAFEL test. Microscopic examination of corroded surfaces was conducted to give insight upon the corrosion mechanism and the occurring type of failure. The results indicate that all tested types of paint have resulted in a reduction in the corrosion rate compared with the uncoated steel. A minimum corrosion rate of 0.8 mm/year for the coat ”Hempalin Enamel 52140” was obtained compared to 2.1 mm/year for the uncoated steel. A microscopic examination of the corroded steel surfaces was conducted which prevailed pitting behavior with different degree. The minimum corroded surface exhibited few pitting attack in comparison to other specimens. Although the pitting attack of the surface layer (paint), one can drive a conclusion that sample surface without coating is aggressively attacked by pits. In addition, surface roughness measurements were conducted for the corroded surfaces. The results have indicated, as expected, that with the increase of corrosion rate, the surface roughness simultaneously increase.