Corrosion Fundamentals

Forms of Corrosion

Corrosion Control

Sources of Additional Information

Fretting Corrosion

The rapid corrosion that occurs at the interface between contacting, highly loaded metal surfaces when subjected to slight vibratory motions is known as fretting corrosion.

The photo above shows fretting corrosion of a fence post and wires which swing in the wind and wear against the post. Both the fence post and the connecting wires are experiencing fretting corrosion.

This type of corrosion is most common in bearing surfaces in machinery, such as connecting rods, splined shafts, and bearing supports, and often causes a fatigue failure. It can occur in structural members such as trusses where highly loaded bolts are used and some relative motion occurs between the bolted members.

Fretting Corrosion of Bearing Race
(Courtesy of www.emersonbearing.com)

Fretting corrosion is greatly retarded when the contacting surfaces can be well lubricated as in machinery-bearing surfaces so as to exclude direct contact with air.

The bearing race above is a classic example of fretting corrosion. This is greatly retarded when the contacting surfaces can be well lubricated as in machinery-bearing surfaces so as to exclude direct contact with air.

The fretting on a large aluminum part (above left) led to deposits of debris (shown in the cross sections on the right). The vibratory motions rubbing back and forth also produced the fatigue cracks shown in the section on fatigue corrosion.