That's an excellent question! As someone who cares about durable and beautiful public spaces, you'll be glad to know that modern steel park benches undergo sophisticated treatments to fight corrosion. The goal is to create a bench that withstands decades of sun, rain, and use.
The primary defense is Hot-Dip Galvanization. Here, the fabricated steel frame is immersed in a molten zinc bath. The zinc bonds metallurgically to the steel, creating a sacrificial layer. If the coating is scratched, the zinc corrodes first, protecting the underlying steel. It's the gold standard for long-term protection.
For aesthetics and an extra barrier, Powder Coating is almost always applied over the galvanized layer. Electrostatically charged dry powder (polyester, epoxy, etc.) is sprayed on and then baked into a hard, seamless finish. This provides incredible color retention, UV resistance, and prevents chipping better than traditional paint.
Some manufacturers use pre-galvanized steel (coated before fabrication) for certain parts, though post-fabrication dipping is more thorough. For high-end benches, additional treatments like chromate conversion coatings under the powder coat enhance adhesion and corrosion resistance further.
Regular maintenance like cleaning and inspecting for deep scratches also prolongs life. So, next time you see a vibrant, rust-free bench, you'll appreciate the advanced science—from its zinc shield to its tough powder coat—keeping it welcoming for years to come