Stop Galvanic Corrosion: Examples & Prevention Tips

Far too many manufacturers treat rust prevention like an optional extra until it becomes a PR nightmare. We see products fail not because of bad blueprints, but because of an invisible electrochemical brawl known as what is galvanic corrosion.

As a supplier of testing gear that actually works, we are here to break down the mechanics, show you real-world galvanic corrosion examples, and help you stop this silent killer from eating your profits.

Key Takeaways

• It is an accidental battery: Galvanic corrosion happens when two different metals connect in a wet environment, causing the active metal to corrode while protecting the noble one.
• The risk is everywhere: We see this failure mode in everything from historical structures like the Statue of Liberty to modern technologies like EV batteries and medical stents.
• The table is just a guide: While the galvanic corrosion table helps predict compatibility, real-world variables like temperature mean you should not rely on it exclusively.
• Watch the aluminum and steel mix: This common combination is risky. A small aluminum part on a large steel assembly will corrode rapidly due to the "Area Effect."
• Insulation is your friend: Breaking the electrical circuit with plastic washers or sleeves is often the simplest and most effective way to stop the rot.
• Testing beats guessing: Simulation with equipment like Salt Spray or Cyclic Corrosion chambers is the only way to be 100% sure your design will last.

What is Galvanic Corrosion?

Galvanic corrosion, or bimetallic corrosion, occurs when two dissimilar metals are electrically connected in a corrosive environment. This connection causes the more active metal (the anode) to corrode preferentially while the more noble metal (the cathode) remains protected.

Think of it as a battery that works against you. When two mismatched metals connect and get splashed with a conductive liquid, they create an electrical loop. This electrochemical process accelerates corrosion due to the flow of electrons from the anodic to the cathodic metal.

The result is that the "active" metal gets chewed up at record speed. identifying exactly what is galvanic corrosion doing to your specific assembly is often harder than it looks on paper.

Common Galvanic Corrosion Examples

To get why this matters, you have to look beyond the textbooks. We see plenty of real-world galvanic corrosion examples across industries that cost companies millions.

One of the most famous historical examples is the Statue of Liberty, where the iron skeleton dissolved where it touched the copper skin.

However, recent studies highlight more modern risks. For instance, researchers have documented significant corrosion in steel-copper couples buried in acidic soils.

We also see this in high-tech sectors. In the energy storage world, galvanic corrosion of lithium metal anodes is a major challenge in Lithium-Sulfur batteries. Even the medical field isn't safe; overlapping metallic stents and vascular plugs can suffer from increased material degradation due to galvanic interactions.

Of course, we are seeing the exact same headache in the Electric Vehicle (EV) industry. Recent research confirms that current flow in electrical parts of EVs significantly impacts galvanic corrosion rates. With all that voltage flowing, the chance of a reaction is huge.

In our humble opinion, the rush to make cars lighter has inadvertently turned metal compatibility into a massive engineering headache.

Using a Galvanic Corrosion Table

So, how do the smart guys figure out which metals play nice together? They grab a galvanic corrosion table, or galvanic series.

This cheat sheet ranks metals by how electrically pushy they are in seawater. Careful material selection to reduce potential differences is one of the primary ways to mitigate risk. Here is a simplified version of what you need to look out for:

How to use the table:

The wider the gap between two metals on the list, the bigger the voltage punch. To play it safe, pick metals that are neighbors.

But don't treat this chart like the absolute truth. Real life is messy. Temperature swings and fluid flow can flip the script, which is why we think testing the real thing beats guessing every time.

The Big Challenge: Galvanic Corrosion Aluminum and Steel

For most of you making things, the love-hate relationship between galvanic corrosion aluminum and steel is the main event. Everyone loves aluminum because it is light, and steel because it is tough.

But on the chart above, you can see the problem: aluminum is way more "active" than steel. Direct contact or even copper contamination can cause aluminum to corrode significantly faster due to its active nature compared to steel.

This makes galvanic corrosion aluminum and steel connections particularly tricky in outdoor infrastructure, like solar panel racking or road signage.

The "Area Effect": Why Size Matters

This is where we see the most critical design errors. When dealing with galvanic corrosion aluminum and steel, the relative surface area of the metals plays a massive role in how fast the damage spreads.

• The Nightmare Scenario (Small Anode, Large Cathode): If you use tiny aluminum rivets on a giant steel sheet, the corrosion lasers in on those poor little rivets. They will rot out and snap in no time.
• The Better Bet (Large Anode, Small Cathode): If you use steel rivets on a big aluminum sheet, the damage spreads out over the large aluminum surface. It is way less severe and much slower.

Strategies for Preventing Galvanic Corrosion

Once you spot a problem, preventing galvanic corrosion is all about being clever with your build. Here is what actually works:

Select Compatible Materials

The most effective defense starts at the drawing board. Strategies to prevent galvanic corrosion include minimizing electrical contact between dissimilar metals and careful material selection.

If you can't use the same metal, we strongly advise checking the list to find compatible neighbors.

Break the Circuit with Electrical Insulation

If you have to mix metals, put a wall between them. We are talking plastic washers, nylon sleeves, or rubber gaskets. In our experience, simple solutions are often the most reliable. Even a hair-thin gap is enough to stop the electrons cold.

However, you need to be sure that seal holds up against moisture over time. This is exactly why successful strategies for preventing galvanic corrosion often involve running checks using a Quali22L Benchtop Environmental Chamber to see if the insulation survives the humidity that fuels the corrosion.

Apply Strategic Coatings and Control Environment

Applying paint or passivation layers is critical.

Advanced methods, such as using Mg-Al layered double hydroxides for aluminum-magnesium joints, are proving effective. Additionally, controlling environmental factors like ion concentration can drastically reduce the reaction rate. 

However, we often have to correct a common misconception here: if you can only paint one side, paint the cathode (the noble metal), not the anode.

Use Sacrificial Anodes

Sometimes you can’t stop the corrosion, so you redirect it. This involves bolting on a chunk of third, highly active metal like zinc to your system.

This "sacrificial anode" eats the corrosion while your expensive parts stay shiny. A classic example is the household water heater, where a magnesium rod dissolves over time so the steel tank doesn't burst.

Verify Your Protection with Environmental Testing

Theory is one thing, but endurance is another. While modern modeling approaches help predict corrosion behavior by simulating electrochemical and mechanical interactions, we honestly believe even the smartest designers can’t fully predict nature without hard data.

At Qualitest, we help you check your work without blowing your budget. We don't think reliable testing gear needs to cost a fortune.

• Salt Spray Chambers: Our standard Salt Spray Tester - Fog Cabinet follows all the strict rules so your results actually mean something. If you have larger batches or need precise programmability, our QPSST Programmable Salt Spray Test Chamber (which goes up to a massive 1280L) is the heavy lifter that sticks to ASTM B117 guidelines like glue.
• Cyclic Corrosion Test Chambers: For the car guys, our QCCT Programmable Cyclic Corrosion Test Chamber switches between salt, dry, and wet cycles. For industries like automotive, we consider this essential since constant salt spray rarely reflects the gritty reality of road conditions.
• Electronics & Stress Testing: For those of you dealing with sensitive electronics in these assemblies—like in EV battery management systems—we also recommend the HAST Highly Accelerated Stress Test Chamber to see how your components age under pressure before the corrosion even sets in.

Stop Galvanic Corrosion with Qualitest

Ignoring this stuff is pricey. But with the right materials and some solid testing, you can avoid the headache. Whether you are dealing with galvanic corrosion aluminum and steel interfaces in an EV battery or picking metals from a galvanic corrosion table, checking your work is key.

In our book, buying a test chamber costs pennies compared to a massive recall. We invite you to check out our range of effective environmental testing solutions.

Ready to proof your products against corrosion? Explore our Environmental Chambers Collection here to find the right testing solution for your lab.

References:

• Bi, C., Zhu, Y., Li, X., , J., Zhang, X., Zhao, M., Li, B., & Huang, J. (2025). Galvanic Corrosion of Lithium Metal Anodes in Lithium-Sulfur Batteries. Journal of the American Chemical Society.
• Istanbullu, O., Akdoğan, G., Yılmaz, H., & Istanbullu, M. (2025). Electrochemical Assessment of the Galvanic Corrosion and Metal Ion Release in Overlapping Stent and Vascular Plug Systems. Journal of biomedical materials research. Part A, 113 6, e37946.
• Lim, J., Park, E., Kim, Y., Kim, B., Ahn, S., & Kim, J. (2025). Effect of Current Flow on the Galvanic Corrosion in Electrical Parts of Electric Vehicles. IEEE Transactions on Transportation Electrification, 11, 1324-1331.
• Nakatsugawa, I., Bian, M., Furushima, R., Charles, M., Gholipour, J., Wanjara, P., & Pekguleryuz, M. (2025). Effect of Mg2+ Ions on Galvanic Corrosion of Linear Friction Welded Magnesium AZ91 Alloy - Aluminum AA6061 Alloy. Journal of The Electrochemical Society.
• Smith, F. (2023). Galvanic and Deposition Corrosion. Materials Performance.
• Wang, Q., Zhang, J., Gao, Y., Dai, N., Chen, Y., Lin, D., & Xia, X. (2022). Galvanic Effect and Alternating Current Corrosion of Steel in Acidic Red Soil. Metals.
• Zhao, J., Jafarzadeh, S., Rahmani, M., Chen, Z., Kim, Y., & Bobaru, F. (2021). A peridynamic model for galvanic corrosion and fracture. Electrochimica Acta, 391, 138968.