Contact corrosion

Contact corrosion is a specific phenomenon that can occur in metallic materials when two different metals or alloys are in direct contact with each other and are simultaneously exposed to a corrosive environment. This corrosion mechanism is also known as contact corrosion or galvanic corrosion.

In contact corrosion, corrosion occurs at the points of contact between the metals due to their different electrochemical properties. When two different metals come into contact in an electrolytic environment, such as in the presence of moisture or salt solutions, a galvanic cell can form. This electrochemical process causes one of the metals to corrode preferentially while the other is protected.

This corrosion phenomenon can be particularly problematic as it can lead to localized corrosion at the contact points, even if the surrounding surface is less susceptible to corrosion. The affected areas can be damaged by pitting, cracking or other forms of corrosion.

Careful selection of materials is essential to minimize contact corrosion. This can be achieved by using corrosion-resistant alloys, insulating the metals from each other or using barrier coatings. Precise knowledge of the environmental conditions and the electrochemical properties of the metals involved is essential in order to assess the risks of contact corrosion and take suitable protective measures.