(Editor's Note: A deeper look at top-side, forward-looking corrosion protection. Part 1 can be found here.)
The future of corrosion prevention in oil and gas pipelines and other heavy equipment lies in protective Nanocoatings; however, differences in nanocoating structure and resistance can make or break nanocoating success in industrial applications. The right choice in terms of adhesion or bond strength, structure, and scope of resistance to aggressive corrosion environments, can greatly delay costly recoat maintenance and extend metal asset service life.
Carbon-based nanocoatings coatings rely on mechanical adhesion, wherein the coating fills voids or pore in the metal substrate and holds the materials together by interlocking. Initial bond strength will be reduced if the substrate profile changes in any way, through impact or extended exposure to vibration, during or after the curing process. In addition, organic resins are inherently susceptible to UV damage and oxidation, making them less suitable for many industrial metal applications.
Silicon-based NanoCeramic coatings rely on chemical bonds with crosslinking properties. Chemical bonds are direct: the metal substrate and coating share electrons to form a unified structure at the join. NanoCeramic coatings unify dissimilar materials of various types (similar to silane coupling agents), but have additional crosslinking properties that “tie” together substrate and coating. The unifying structure tightly limits filiforming of coating past 1 mm beyond point of impact.
NanoCeramic (silicon) structure is highly durable, even at the atomic level, due to the inherent strength of Silicon-Oxygen bonds that require a great deal of energy to break. NanoCeramic coatings may also comprise other natural properties of ceramic materials, including high abrasion resistance (39.11 on the ASTM Taber Abrasive test, 70-75 on the Rockwell Scale and 7.5 on the Mohs Scale), natural heat, oxidation resistance and UV stability, depending on their formulation specifics.
Additional advancements in strong bonding NanoCeramic coatings have begun to prove themselves as leading contenders for comprehensive resistance to common corrosion-causing factors found in the industrial environment.
One such example of NanoCeramic success is Ionyx. According to Douglas Foster of Intuitive Coatings, maker of Ionyx, the NanoCeramic coatings feature very high cross-link density to promote excellent bonding strength not only with substrate metal, but also within the coatings (to further enhance corrosion and chemical resistance). The unique formulation is created through a proprietary process that organizes small volumes of organic polymers and large volumes of inorganic oxides into a lattice structure. The result is a hard-to-beat combination of strength, hardness, durability, UV resistance, high chemical resistance (including methylene & chlorides), elasticity, water-repellency, tensile strength and flexibility.
The lattice structure resists cracking and shattering, limiting filiform to less than 1mm, even on impact. The high resistance and non-reactivity is also part of the reason these air-curable coatings may be successfully applied in temperatures between 45°F to 105°F, with relative humidity up to 90%.
While actual industrial applications of the coating are just beginning to hit the five- to ten-year assessment mark, it has been proven to retain protective properties in high heat conditions (up to 500°), and scored 10 /10 after 1,000 hours of third-party Accelerated Weathering/Cyclic Corrosion testing. Looking forward, Foster is already onto the next advancement. Foster states, “our new “NanoRebar” strengthened coating (currently in development), showed initial third-party test results over 9H. That’s almost unheard of in the coatings world!”