Galvanic corrosion is defined as corrosion due to electrical contact between dissimilar metals. How can it be prevented in assemblies?

Galvanic corrosion is defined as corrosion due to electrical contact between dissimilar metals. How can it be prevented in assemblies?

• A. Corrosion due to chemical reaction with oxygen.
• B. Corrosion due to moisture soaking; prevention by drying.
• C. Corrosion due to temperature differences; prevent by insulation.
• D. Corrosion due to electrical contact between dissimilar metals; prevention by isolation, coatings, or insulating materials.

Answer: (D)

Galvanic corrosion happens when different metals are in electrical contact in a conductive environment. The electrical path allows the more anodic metal to corrode while the other metal remains protected. To prevent this in assemblies, you break or insulate that electrical path and keep metals from contacting each other or from exposure to electrolytes. This is done by using nonconductive barriers or spacers, applying coatings or insulating finishes to surfaces and fasteners, and choosing insulating materials at joints. By isolating the metals, coating interfaces, or using insulating components, galvanic currents are interrupted and corrosion is prevented.

Galvanic corrosion happens when different metals are in electrical contact in a conductive environment. The electrical path allows the more anodic metal to corrode while the other metal remains protected. To prevent this in assemblies, you break or insulate that electrical path and keep metals from contacting each other or from exposure to electrolytes. This is done by using nonconductive barriers or spacers, applying coatings or insulating finishes to surfaces and fasteners, and choosing insulating materials at joints. By isolating the metals, coating interfaces, or using insulating components, galvanic currents are interrupted and corrosion is prevented.