Galvanic Corrosion: What it is and how to avoid it

Have you ever wondered just how important the types of materials you use on projects are? Galvanic corrosion proves that material types are essential. If you put the wrong two substances near each other, you could end up with material breakdown and weaknesses.

The most common place for this corrosion to take place is within seawater. For this corrosion to happen, there have to be three conditions present.

1. Two electrochemically dissimilar metals are being used
2. Those two metals are connected by electrical contact
3. Both metals are exposed to an electrolyte (i.e., salt from seawater)

Protect your worksite and finished projects from this corrosion by reading up on what it is and you to prevent it.

What is Galvanic Corrosion?

Galvanic corrosion is the electrochemical process of one metal corroding when it comes in electrical contact with another metal while in the presence of an electrolyte. This process is also known as bimetallic corrosion, and just like the name sounds, it involves two different metals.

But there's more to it than just using two different types of metals. These metals also must be immersed in a conductive solution that can connect them electrically. The metals are dissimilar. One is protected and referred to as the cathode. The other is corroded and acts as the anode.

The anode’s corrosion accelerates compared to its corrosive behavior when not in contact with the cathode.

An example of when this process can occur is if you were to connect aluminum and stainless steel immersed in seawater.

How to Prevent Galvanic Corrosion

You can prevent and reduce this corrosion process by carefully selecting your materials and adding precautions to slow the process. Based on your project requirements, evaluate whether you could take any of the following precautions.

1. Choose metals that have similar corrosive properties.
2. Insulate the metals from one another to break the electrical connection that facilitates the corrosion.
3. Coat both of the metals. The cathode is protected by its coating, so by adding a coating to the other material, you can prevent the corrosive process.
4. Use a spacer to separate the materials so they are not in contact.
5. Add a metal that is anodic to both other metals used. In this case, you sacrifice an unimportant metal piece (zinc is commonly used for this purpose) to slow the corrosion of your essential materials.
6. Insert a corrosion inhibitor at the start to avoid the process.

When you can’t use any of these preventative measures, you can minimize the corrosion rate by making the area between the two metals large.

Assistance with Choosing the Right Materials

The team at Eurolink Fastener Supply Service knows the importance of avoiding this corrosive process. We can help you by making recommendations for the best fasteners for the job.

Call our team at 864-801-0505 to discuss your needs or the challenges you’ve faced in the past with corrosion. Our team will get you the materials you need for a long-lasting product. Request a fast quote today.