Coatings remain the most dominant mode of protection against environmental degradation across a wide range of industries. Coating systems that are used in most industries are comprised of pretreatment followed by one or more organic layer(s). This pretreatment layer is highly effective to enhance corrosion protection. However, when protecting infrastructure in marine environments, a pretreatment process is not traditionally utilized. This is largely due to the size and scope of these projects and their incompatibility with traditional pretreatment methods. In this paper we introduce a novel surface engineering technology and compare the performance of conventional coatings utilizing this innovative preparation against traditional preparatory methods.
Coatings remain the leading mode of protection against corrosion for large steel structures in many harsh environmental conditions, such as marine environments.1,2 Critical infrastructure in such environments must successfully withstand years of corrosive atmospheric exposure between recoatings to remain structurally viable.2 In such environments, the first coating layer following surface preparation is often a primer containing either organic or inorganic zinc.3 Subsequent coatings usually include an epoxy type mid-coat and polyurethane top-coat. These coating layers are typically applied at very thick dry film thicknesses to achieve efficient protective capacity.
Smaller steel assets that are commonly produced in industrial or automotive markets have traditionally used a different approach to achieve a high level of corrosion protection: deposition of an inorganic pretreatment layer prior to coating application.4 The use of phosphate conversion coatings or thin-film inorganic layers under the coating system provide an added level of protection to the steel.4 While these assets are not typically subjected to the same level of corrosive atmosphere as infrastructure in coastal or marine settings, the pretreatment layer does provide additional corrosion mitigation leading to reduced maintenance and coating material required to maintain an acceptable lifecycle. This additional protection would be highly beneficial for marine assets as well.
