South Atlantic – We Analyze the Different Types of Steel Corrosion
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When you’re planning a project that needs to stand the test of time, rust is your enemy. Corrosion can eat into your venture, compromising structural integrity and requiring extensive maintenance or replacement. There are different types of steel corrosion, and each one behaves a bit differently.
In this blog, we’ll take a closer look at the different types of steel corrosion, their causes, and how hot-dip galvanization can help protect your investment.
At South Atlantic, not only do we have more than 2,000 tons of galvanized steel ready to ship, but our hot-dip galvanizing meets or exceeds all ASTM standards. With a rigorous, 25-point QA process, you don’t have to worry about quality when you work with South Atlantic. We understand you have deadlines, and that’s why our reliable, on-time delivery helps you stay on track and within budget. Want to learn more about how we’ve got you covered? Contact us for a reliable and comprehensive quote today.
What Are the Different Types of Steel Corrosion?
There are several different types of steel corrosion, and different environments can trigger various types.
The different types of steel corrosion include:
- Uniform/General Corrosion
- Pitting Corrosion
- Crevice Corrosion
- Intergranular Corrosion
- Stress Corrosion Cracking (SCC)
- Erosion Corrosion
Next, we’ll examine each in more detail.
What Is General Corrosion?
This is typically spread evenly across the surface, primarily caused by moisture exposure, high temperatures and humid environments.
What Is Pitting Corrosion?
Unlike general corrosion, pitting corrosion causes holes or cavities in the steel usually localized in a certain area. It’s formed when the passive oxide layer breaks down, typically caused by saltwater or even de-icing salts.
It’s hard to detect because it’s not always visually obvious. However, failure to locate these problems and address them can cause dangerous, sudden structural failure.
You can help prevent pitting corrosion through corrosion-resistant alloys and protective coatings.
What Is Crevice Corrosion?
When there is a confined space and the steel is exposed to stagnant water, it can set the stage for crevice corrosion. You’ll often find it between parts, inside cracks or under gaskets. This type of corrosion primarily affects steel in the marine, chemical processing and construction industries. Through proper joint design, along with sealing methods, you can reduce the likelihood of developing crevice corrosion.
What Is Intergranular Corrosion?
Metals are made up of millions of microscopic grains. They are packed together, and the places where those grains meet can be vulnerable to intergranular corrosion. In this type of corrosion, the “body” of the grain is fine, whereas the boundaries are deteriorating due to rust.
What Is Stress Corrosion Cracking?
When steel is under intense stress, such as being bent, while being exposed to a harsh environment at the same time, stress corrosion cracking can occur. These cracks can spread throughout the metal, causing extensive damage.
What Is Erosion Corrosion?
Speed and corrosion combine to create erosion corrosion. It occurs when a damaging fluid quickly moves across a metal surface. Its speed enables it to wear down the metal.
This is a two-pronged “attack.” The fluid is damaging the metal, while, at the same time, scrubbing it like sandpaper.
Does Galvanizing Prevent All Forms of Corrosion?
Galvanizing provides robust corrosion protection thanks to a protective layer of zinc that keeps the steel underneath safe from rust. Hot-dip galvanizing involves immersing the steel in a bath of molten zinc. Electroglavanizing applies a layer of zinc using electrical currents.
While both supply protection, hot-dip galvanizing creates a stronger bond, making it a better choice to help ensure the longevity of your project.
While hot-dip galvanizing is incredibly effective, extreme environments or damaged coatings can set the stage for rust.
While it cannot prevent all forms of corrosion, it can protect steel effectively for more than 50 years.
Protect Your Project From Corrosion With Reliable Hot-Dip Galvanizing From South Atlantic
When it comes to helping ensure your project will last for decades, South Atlantic has you covered. We take away your stress so you can concentrate on other aspects of your venture.
With fast turnaround and stellar customer service, you can rest assured you’ll get the quality you need on time. Contact us today for a quote.
Key Takeaways
- Rust and corrosion are major threats to steel projects, compromising structural integrity and increasing maintenance costs.
- There are six main types of steel corrosion: uniform/general, pitting, crevice, intergranular, stress corrosion cracking, and erosion corrosion.
- Each corrosion type has distinct causes, from moisture and saltwater to mechanical stress and fast-moving fluids.
- Pitting corrosion is especially dangerous because it’s difficult to detect visually yet can cause sudden structural failure.
- Hot-dip galvanizing — which bonds a zinc layer to steel via a molten bath — offers stronger, longer-lasting protection than electro-galvanizing.
- Hot-dip galvanizing can protect steel effectively for more than 50 years.
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Sources:
American Galvanizers Association, “Types of Corrosion,” https://galvanizeit.org/corrosion/corrosion-process/types-of-corrosion
Association for Materials Protection and Performance, Intergranular Corrosion, “https://www.ampp.org/technical-research/impact/corrosion-basics/group-2/intergranular-corrosion#:~:text=Intergranular%20corrosion%20is%20a%20localized%20attack%20along,decay**%20*%20**Knife%2Dline%20attack**%20*%20**Exfoliation%20corrosion**
Galvanizers Association (UK), “Corrosion Types,” https://galvanizing.org.uk/corrosion/types/
Galvanizers Association of Australia, “Can Galvanized Metal Rust?” https://gaa.com.au/2023/04/06/can-galvanized-metal-rust/#:~:text=Additionally%2C%20galvanized%20metal%20can%20also,remains%20durable%20and%20long%2Dlasting.
NASA, “Forms of Corrosion,” https://public.ksc.nasa.gov/corrosion/forms-of-corrosion/
NASA, “Corrosion Fundamentals,” https://public.ksc.nasa.gov/corrosion/corrosion-fundamentals/
Rust Bullet Australia, “Introduction to Corrosion and Process,” https://www.rustbullet.com.au/technical/how-it-works/introduction-to-corrosion-and-process/#:~:text=Corrosion%20is%20the%20deterioration%20of%20materials%20by,to%20each%20other%20on%20the%20metal’s%20surface.
