How to Choose Corrosion-Resistant Coatings for Steel Structures?

In the field of steel structure corrosion prevention, the "Triple Swordsmen" combination showcases its prowess alongside innovative coatings. Epoxy zinc-rich primer, epoxy iron oxide intermediate coating,Acrylic AcidPolyurethane (or fluorocarbon) topcoats form a classic protective system that has stood the test of decades in large-scale projects.​

Epoxy zinc-rich primer serves as the first line of defense, containing over 70% zinc content. The zinc powder forms a conductive network, acting as a "bodyguard" for the steel surface by protecting it through sacrificial anode. When the steel surface sustains minor damage, the zinc powder oxidizes first, forming a dense zinc oxide layer to block the intrusion of corrosive agents. Particularly suitable for long-term protection of substrates like bridges and tanks, it maintains electrochemical protection for over 5 years even in high-dust industrial environments.​

Mid-layer epoxy iron oxide paint, constructed with lamellar mica iron oxide to form a physical barrier like "armor," layer upon layer to block moisture and salt penetration. Its unique lamellar structure extends the penetration path of corrosive mediums by 3-5 times, while enhancing adhesion with the upper and lower paint layers, increasing the overall coating thickness to 150-200μm. In coastal humid areas, it effectively delays the blistering and peeling of the coating on steel structures.​

Surface Paint SelectionAcrylic AcidPolyurethane or fluorocarbon paint. The former boasts excellent weather resistance, showing no significant powdering after 5 years of outdoor exposure and maintaining over 80% of its luster, making it ideal for the exterior decoration of city landmarks. The latter excels in resistance to acids and alkalis and has superior UV protection, preserving its luster for over 15 years in coastal high-humidity environments, making it the perfect choice for facilities like port cranes and offshore platforms, and is often referred to as the "face" of the system.​

New TypeSpecialty Cyanogen-based Waterproof and Anticorrosion CoatingInnovating Tradition: The New Coating Unites the Bottom Surface. Designed for two-component paints, it requires mixing in specific proportions before use. It is a rigid coating that, upon curing, forms a hard protective layer with compressive strength exceeding 20MPa and can withstand certain external impacts. Although component mixing is necessary during application, the process is not complicated. The three-layer cyanoglycol coating has a thickness of approximately 300 micrometers, excelling in damp environments such as underground tunnels and wastewater treatment pools. It provides both waterproofing and corrosion resistance, achieving the effects of a conventional three-layer system, and can be applied in a single pass with a thickness of up to 100μm, reducing the construction period by 40%. It has become an efficient choice for small-scale projects.​

These coatings, from division to integration, construct protective barriers through various mechanisms, safeguarding the safety and lifespan of steel structures comprehensively.