Which Has a Higher Corrosion Rate: Galvanized vs. Weathering Steel?
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You need a long-term solution.
When working on a project–particularly one that will be exposed to harsh environments– you want to use a material that is durable, reliable and requires minimal maintenance. Two common metals that come to mind are galvanized steel and weathering steel.
In this article, we’ll take a closer look at galvanized vs. weathering steel, their distinct advantages and which one serves as the best choice for long-term corrosion protection.
At South Atlantic, we are America’s only manufacturer of stocked, pre-galvanized steel. With a rigorous QA process, our one-stop solution makes ordering easy. We have more than 2,000 tons of galvanized steel ready to ship.
What’s the Difference Between Galvanized vs. Weathering Steel?
While galvanized steel offers corrosion protection through a zinc coating, weathering steel (Corten steel) prevents corrosion by developing its own protective layer of rust (patina).
Both are used in bridges, buildings and sculptures.
Galvanized steel is a long-term solution, not a short-term one. It’s best suited for specific environments and applications, particularly in marine or hostile environments.
Which Steel Has a Higher Corrosion Rate?
Typically, weathering steel has a higher corrosion rate, particularly in a moisture-rich environment, which can cause it to lose steel mass. The corrosion rate is often unpredictable, and in marine environments, weathering steel may disintegrate quickly.
By contrast, galvanized steel’s protective zinc coating endures, and it is ideal for marine or moisture-rich environments.
Which Option Is Easier to Inspect for Corrosion?
It’s often difficult to determine the difference between weathering steel’s protective layer of rust and the damaging rust that jeopardizes structural integrity. Therefore, expensive and detailed testing must be conducted to determine if the weathering steel still has the strength and corrosion protection needed to maintain structural integrity.
However, galvanized steel can be easily visually inspected. Testing only requires inexpensive, hand-held tools.
Can You Galvanize Weathering Steel?
Yes, you can. While some may see “doubling” the corrosion protection as excessive, galvanizing weathering steel is a wise choice. Doing so means the steel will perform better in moisture-rich environments, making it a good choice for bridges, marinas and certain DOT projects.
South Atlantic Is Your Leading Source for Quality Galvanized Steel
When you need a long-term solution to corrosion protection, galvanized steel is the natural choice. Its layer of zinc offers excellent protection without the need for extensive maintenance.
Our easy ordering and quick service means we can ship galvanized steel products directly from our inventory in a timely manner so you can meet your deadlines. You can give quotes with confidence thanks to our upfront pricing.
Ready to get started? Discover the many ways South Atlantic’s got you covered. Contact us for a quote today.
Key Takeaways
- Galvanized steel protects against corrosion with a zinc coating, while weathering steel forms a protective rust layer over time.
- Galvanized steel performs better in moisture-rich or marine environments due to its durable, sacrificial zinc barrier.
- Weathering steel typically corrodes faster in humid or wet conditions, making it less reliable for long-term use in such environments.
- Galvanized steel allows for easy, low-cost visual inspections to assess corrosion levels.
- Weathering steel requires expensive testing to determine whether the rust layer is still protective or structurally damaging.
Galvanizing weathering steel is possible and can enhance performance in corrosive environments, especially for infrastructure like bridges and marinas.
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Sources:
American Galvanizers Association, “Galvanized Steel vs. Weathering Steel,” https://galvanizeit.org/uploads/publications/Galvanized_Steel_vs_Weathering_Steel.pdf
American Galvanizers Association, “Galvanizing Weathering Steel,” https://galvanizeit.org/knowledgebase/article/hot-dip-galvanizing-weathering-steel
