Fretting Corrosion
Description
Fretting corrosion is corrosion that can occur on the load
bearing contact surface between mating material. It is caused by
the combination of corrosion and the abrasive effects of
corrosion product debris often seen in equipment with moving or
vibrating parts. Other problems induced by fretting corrosion
include: surface pitting. seizing and galling of mating surfaces.
reduced fatigue life as a result of stress concentrations
produced on the metal surface.
Prevention or Remedial Action
- use of lubricants and surface coatings designed to
improve lubricity and limit metal-on-metal wear.
- increased surface hardness.
- use of barriers to limit ingress of corrosive environment
to mating surfaces.
- reduce bearing loads on mating surfaces.";
Standard Test Methods
- ASTM G-77 - practice for ranking materials to sliding
wear using block-on-ring wear test.
- ASTM G-98 - test for galling resistance of materials.
Evaluation of Fretting Corrosion
Fretting corrosion is prodcued by the combined effects of
corrosion and wear. Therefore, factors influencing either the
severity of corrosion or the bearing load between the surfaces
can affect fretting corrosion. Parameters that need to be
controlled in fretting corrosion evaluations include:
- corrosive environment
- contact load
- amplitude and frequency of load flucuations
- cycles
- temperature
- availability of moisture
Typically the more volumous the corrosion product and the high
the bearing loads, the more intense will be the fretting
corrosion response in service.
