Effect of Hydrogen Absorbent Material in Conductive Coating ICCP System
摘要
Even though cathodic protection is a common method of corrosion mitigation in many industries, there are some major problems and limitations associated with the way it is commonly applied. When used for the protection of marine vessels it only protects parts that are completely submerged in water, while it fails at protecting parts that are in intermittent contact with water or subject to humidity. It also does not adequately protect parts in the shadow of other parts or not facing the anodes. When used for the protection of steel structures that are in contact with water, which are often more complicated than marine vessels in terms of protection, common systems of cathodic protection are not as effective as desired. In such structures, there are buried parts, parts that are submerged in water, parts with intermittent contact with water (waves and tides), and elevated parts that are in contact with humid air and mist. Hence, in common cathodic protection systems, in which rigid anodes are placed out of reach of most parts of the cathode surfaces, the anodes cannot be present in the created electrolytes at most parts of the cathode. Conductive Coating ICCP (Impressed Current Cathodic Protection) Systems can overcome these problems by directly applying the anode on the surface of the cathode (substrate). This method will reduce the current required and therefore the power, eliminating the stray current corrosion, and simplifying the installation process thus reducing the overall cost of the system. However, this system suffers from some issues stemming from overprotection, during which hydrogen gas is released at the cathode. In many cases, this gas tends to diffuse and accumulate under the coating, causing blistering and eventually leading to what is known as filiform corrosion. A hydrogen-absorbent material is required to overcome this problem. This research will focus on determining the most suitable absorbent and catalyst materials as well as their proportions.