Fretting Corrosion

on . Posted in Cathodic Protection

Fretting corrosion, also called fretting wear or fretting fatigue, is a type of wear related corrosion that occurs in small, repetitive, oscillatory movements between two surfaces that are in contact under load.  This motion can lead to wear, as well as the initiation and propagation of corrosion in the contacting materials.  This is particularly common in mechanical systems where there is slight relative motion or vibration between two surfaces.  

Key Points about fretting corrosion

  • Conditions for Fretting Corrosion  -
    • Presence of moisture or corrosive environment.
    • Micro motion or vibration between contacting surfaces.
    • High contact pressure.
  • Materials Affected  -  Fretting corrosion is often seen in materials such as metals and alloys, where the repeated motion can remove protective oxide layers, exposing fresh surfaces to corrosion.
  • Mechanism:
    • The repeated motion causes mechanical wear, which removes the protective oxide layer on the surface of the material.
    • The exposed metal is then susceptible to corrosion.
    • The combination of mechanical wear and corrosion can lead to material loss and structural damage.
  • Prevention and Mitigation  -
    • Lubrication  -  Proper lubrication can reduce the friction between surfaces, minimizing fretting corrosion.
    • Surface Coatings  -  Applying protective coatings on the surfaces can help prevent fretting corrosion.
    • Material Selection  -  Choosing materials with better resistance to wear and corrosion can be an effective preventive measure.
    • Design Considerations  -  Reducing the amplitude of relative motion or providing proper clearances in design can help mitigate fretting corrosion.
  • Applications  -  Fretting corrosion is a concern in various industries, including aerospace, automotive, and manufacturing, where mechanical components are subjected to repetitive motion and load.

Understanding and addressing fretting corrosion is crucial in maintaining the reliability and longevity of mechanical systems.  Engineers and materials scientists employ various strategies to mitigate the effects of fretting corrosion through material selection, design modifications, and preventive maintenance practices.

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