Fretting Corrosion
Fretting corrosion results from continuous destruction of the passive layer on contact surfaces under mechanical loading, producing oxide particles that act as abrasives.
Physicochemical Mechanism of Action
Fretting corrosion occurs when two metal parts are in contact and move under mechanical load. The passive layer, which normally provides protection against corrosion, is continuously destroyed by the constant friction. This leads to the formation of oxide particles on the contact surfaces.
Metallurgical Relevance & Welding Risks
The oxide particles act as aggressive abrasives and further abrade the contact surfaces, accelerating corrosion processes. This can lead to wear of bolts, couplings, or other mechanical parts in contact with each other. Additionally, fretting corrosion can cause increased resistance at the contact surfaces and impair component performance.
Workshop Practice & Instructions
To avoid fretting corrosion, clean the contact surfaces regularly and coat them with a corrosion-resistant protective agent. When selecting materials, make sure they are resistant to mechanical stress and corrosion. In the workshop, set up a regular maintenance schedule to ensure monitoring and care of the contact surfaces.