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.