Steel structure substrate treatment and supporting anti-corrosion system

The corrosive substances of steel structure mainly come from the atmosphere. Salt particles in the ocean-atmosphere, sulfides, phosphides, and dust particles contained in air pollution are all substances that cause corrosion to steel structures.

Steel structure substrate treatment

1. Solvent cleaning: Use a solvent or its vapor, emulsion, alkali, or water vapor to completely remove grease, wax, dust and other dirt.

2. Manual rust removal: use steel brush, spatula, hammer, gauze and other tools to remove floating rust

3. Mechanical treatment: Use electrical power tools to remove rust by impact and friction.

4. Sandblasting treatment: spray sand to completely remove rust, oxide scale and impurities.

5. Flame spray treatment: Use acetylene flame to remove oil stains, remove rust and lose oxide skin, and then use a wire brush or spray to remove rust.

6. Chemical treatment: Use the acid solution to chemically react with iron corrosion to generate iron salt soluble in water to remove rust.

7. Electrochemical treatment: use electrochemical methods to produce a passivation layer on the surface of the steel structure to improve the corrosion resistance.

For steel structures, sandblasting is the most commonly used, and for some parts, chemical or electrochemical treatment methods are also used. After treatment, the surface of the substrate is required to be clean, pollution-free, and expose the original color of the substrate to achieve good infiltration, bonding, and adhesion.

The following three aspects should be considered when designing the supporting anti-corrosion coating system for steel structure:

① Investigate the external factors of steel structure corrosion.

②Determine the protection period of the steel structure.

③Clarify the coating products for anti-corrosion protection construction and the thickness of the paint film during coating.

Here are several high-quality steel structure anti-corrosion supporting solutions:

①Alkyd series (protection for 3~5 years): primer->alkyd anti-rust primer, topcoat->alkyd enamel

②Acrylic series (protection for 5~8 years): primer->epoxy primer, topcoat->acrylic topcoat

③Polyurethane series (protection for 10-15 years): primer->epoxy zinc-rich primer, intermediate paint->epoxy mica intermediate paint, topcoat->acrylic polyurethane topcoat

④Fluorocarbon series (protection for 15-20 years): primer->epoxy zinc-rich primer, intermediate paint->epoxy mica intermediate paint, topcoat->fluorocarbon topcoat