Galvanic Corrosion

Definition:
Galvanic Corrosion (noun): A type of corrosion that happens when two different metals are in electrical contact with each other while moisture or another electrolyte is present. In industrial environments, galvanic corrosion can cause one metal to corrode faster than it normally would, especially around fasteners, brackets, frames, dock equipment, doors, and other metal assemblies exposed to water, humidity, or chemicals.

What Galvanic Corrosion Means in Industrial Settings

Galvanic corrosion is sometimes called dissimilar metal corrosion because it usually occurs when two unlike metals are used together. For example, steel, aluminum, stainless steel, copper, brass, and galvanized metal can react differently when they are connected and exposed to moisture.

The metal that is more likely to give up electrons becomes the one that corrodes faster. The other metal may be protected, which is why the damage often appears uneven or concentrated around the connection point.

Around loading docks, warehouses, and manufacturing facilities, this can happen near exterior doors, dock hardware, galvanized components, metal anchors, railings, brackets, and equipment exposed to rain, washdown water, condensation, or coastal air.

Why Galvanic Corrosion Matters

Galvanic corrosion can shorten the life of metal components and create maintenance problems before the damage is obvious. It may show up as rust, white powdery corrosion, pitting, staining, loose fasteners, or weakened metal around connection points.

This matters in industrial facilities because small corrosion issues can eventually affect equipment reliability, structural connections, appearance, and safety. Areas with standing water, poor drainage, salt exposure, or frequent moisture are usually at higher risk.

What Metals Cause Galvanic Corrosion?

No single metal causes galvanic corrosion by itself. The problem comes from combining dissimilar metals in the presence of moisture or another conductive material.

Common pairings that can create galvanic corrosion concerns include:

• Aluminum in contact with stainless steel
• Copper or brass in contact with steel
• Stainless steel fasteners used with galvanized steel
• Carbon steel connected to more corrosion-resistant metals
• Galvanized metal exposed to certain dissimilar metal connections

The farther apart the metals are in corrosion resistance and electrical potential, the greater the risk can be.

What Helps Prevent Galvanic Corrosion?

Galvanic corrosion can often be reduced by separating the metals, choosing more compatible materials, or limiting exposure to moisture.

Common prevention methods include:

• Using non-conductive washers, gaskets, sleeves, or barriers
• Applying protective coatings or sealants
• Keeping water from collecting around metal connections
• Using compatible fasteners and hardware
• Avoiding unnecessary contact between dissimilar metals
• Inspecting high-moisture areas regularly

Thread sealants, tapes, and coatings may help in some situations because they can create a barrier between metals, but they should not be treated as a complete fix for every application. The best approach depends on the metals involved, the environment, and how the equipment is installed.

Key Takeaways

Galvanic corrosion is an electrochemical reaction that happens when different metals are connected in the presence of moisture. In warehouses, loading docks, and industrial facilities, it can affect fasteners, frames, brackets, galvanized parts, and other metal equipment exposed to water or humidity.

Understanding galvanic corrosion helps maintenance teams choose better materials, protect metal connections, and reduce premature wear in demanding industrial environments.