ASTM G204-10

Standard Test Method for Damage to Contacting Solid Surfaces under Fretting Conditions

SIGNIFICANCE AND USE
Fretting wear and corrosion are potential serviceability factors in many machines. They have always been factors in shipping finished goods by truck or rail. Packing materials rubbing on a product in transit can make the product unsalable. Beverage cans and food cans can lose their trade dress and consumers often equate container damage to content damage.
Clamping surfaces on injection molds are damaged by fretting motions on clamping. This damage is a significant cause for mold replacement.
Machines in shipment are subject to fretting damage in the real area of contact of the bearings on the machines.
Operating vibration and movement of mechanically clamped components, like screwed assemblies, can produce damage on the clamped faces and other faces that affects machine function or use. Many times fretting damage appears in the form of pits, which are stress concentrators that can lead to mechanical fractures.
Electrical contacts in any device that is subject to vibration are susceptible to failure (open circuit) due to fretting damage at real areas of contact.
This test method is intended to be used to identify mating couples that may be less prone to fretting damage than others. This information in turn is used to select materials of construction or surface treatments that are less prone to fretting damage for applications where fretting conditions are known or perceived to exist.
SCOPE
1.1 This test method covers the studying or ranking the susceptibility of candidate materials to fretting corrosion or fretting wear for the purposes of material selection for applications where fretting corrosion or fretting wear can limit serviceability.
1.2 This test method uses a tribological bench test apparatus with a mechanism or device that will produce the necessary relative motion between a contacting hemispherical rider and a flat counterface. The rider is pressed against the flat counterface with a loading mass. The test method is intended for use in room temperature air, but future editions could include fretting in the presence of lubricants or other environments.
1.3 The purpose of this test method is to rub two solid surfaces together under controlled fretting conditions and to quantify the damage to both surfaces in units of volume loss for the test method.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2010
• ICS: 21.260 - Lubrication systems
• Technical Committee: G02 - Wear and Erosion
• Drafting Committee: G02.40 - Non-Abrasive Wear

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: G204 − 10
StandardTest Method for
Damage to Contacting Solid Surfaces under Fretting
Conditions
This standard is issued under the fixed designation G204; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Frettingissmallamplitudeoscillatingmotionusuallyintherangeof10to300µm.Contactingsolid
surfaces subjected to this type of motion can develop significant damage in the form of mass loss,
pitting, debris generation, etc. Frequently, pitting damage caused by fretting creates stress concentra-
tions that contribute to mechanical failures. Most material couples are susceptible to fretting damage
and this test method is intended to assess a tribocouple’s relative susceptibility to damage under
fretting conditions.
When tribocouples experience oscillating relative motion less than about 10 µm, gross slip (all
points in a contact experience relative slip over a complete cycle) may not occur. The elastic behavior
of the real contacts may accommodate this motion and fretting damage may not occur.
When metal couples are subjected to fretting motion, there is a potential for chemical reaction with
the ambient environment to be a component of the damage. In metals rubbing in air, oxidation of
freshly fractured surfaces can occur. When chemical reaction is conjoint with the mechanical damage
producedbyfretting,itiscalledfrettingcorrosion.Whenmostplasticcouplesaredamagedbyfretting
motion,thefracturedsurfacesmaynotreactwiththeenvironmentandfrettingwearoccursasopposed
to fretting corrosion.
1. Scope 1.4 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
1.1 This test method covers the studying or ranking the
standard.
susceptibility of candidate materials to fretting corrosion or
1.5 This standard does not purport to address all of the
fretting wear for the purposes of material selection for appli-
safety concerns, if any, associated with its use. It is the
cations where fretting corrosion or fretting wear can limit
responsibility of the user of this standard to establish appro-
serviceability.
priate safety and health practices and determine the applica-
1.2 This test method uses a tribological bench test apparatus
bility of regulatory limitations prior to use.
with a mechanism or device that will produce the necessary
relative motion between a contacting hemispherical rider and a
2. Referenced Documents
flat counterface. The rider is pressed against the flat counter-
2.1 ASTM Standards:
face with a loading mass. The test method is intended for use
G40 Terminology Relating to Wear and Erosion
in room temperature air, but future editions could include
G99 Test Method for Wear Testing with a Pin-on-Disk
fretting in the presence of lubricants or other environments.
Apparatus
1.3 The purpose of this test method is to rub two solid G133 Test Method for Linearly Reciprocating Ball-on-Flat
surfaces together under controlled fretting conditions and to
Sliding Wear
quantifythedamagetobothsurfacesinunitsofvolumelossfor
3. Terminology
the test method.
3.1 Definitions:
This test method is under the jurisdiction of ASTM Committee G02 on Wear
and Erosion and is the direct responsibility of Subcommittee G02.40 on Non- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Abrasive Wear. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Current edition approved April 1, 2010. Published April 2010. DOI:10.1520/ Standards volume information, refer to the standard’s Document Summary page on
G0204–10. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G204 − 10
FIG. 1 Schematic of a Suitable Fretting Testing Rig
a = loading arm pivot
b = counterface test specimen
c = rider test specimen
d = device to measure rider movement
e = device to measure counterface movement
3.1.1 fretting, n—in tribology, small amplitude oscillating 4.2 Friction forces can be measured during the fretting test,
motion usually tangential between two solid surfaces in but these measurements, as well as reporting these data, is
contact. G40 optional.
3.1.2 fretting corrosion, n—form of fretting wear in which
5. Significance and Use
corrosion plays a significant role. G40
5.1 Fretting wear and corrosion are potential serviceability
3.1.3 fretting wear, n—wear arising as a result of fretting.
factors in many machines. They have always been factors in
G40
shipping finished goods by truck or rail. Packing materials
3.2 Definitions of Terms Specific to This Standard: rubbing on a product in transit can make the product unsalable.
3.2.1 coeffıcient of variation (COV), n—test standard devia- Beverage cans and food cans can lose their trade dress and
consumers often equate container damage to content damage.
tion divided by the test mean.
3.2.2 counterface, n—flat surface that the rider rubs on in
5.2 Clamping surfaces on injection molds are damaged by
this test.
fretting motions on clamping. This damage is a significant
cause for mold replacement.
3.2.3 crater, n—counterface damage in a fretting test from a
hemispherical or spherical rider characterized by loss of
5.3 Machines in shipment are subject to fretting damage in
material in the form of a surface depression.
the real area of contact of the bearings on the machines.
3.2.4 fretting amplitude, n—sliding distance between direc-
5.4 Operating vibration and movement of mechanically
tion reversals (for example, if a dial indicator is used to
clamped components, like screwed assemblies, can produce
measurestroke,theamplitudeistheindicatormovementonthe
damage on the clamped faces and other faces that affects
dial).
machine function or use. Many times fretting damage appears
3.2.5 rider, n—ball or hemisphere that oscillates on another in the form of pits, which are stress concentrators that can lead
to mechanical fractures.
surface to produce fretting damage.
3.2.6 scar, n—damage to either rider or counterface in a
5.5 Electrical contacts in any device that is subject to
fretting test. vibration are susceptible to failure (open circuit) due to fretting
damage at real areas of contact.
4. Summary of Test Method
5.6 This test method is intended to be used to identify
4.1 This test method rubs a spherical or hemispherical solid mating couples that may be less prone to fretting damage than
rider on a solid flat under prescribed conditions to produce others. This information in turn is used to select materials of
fretting damage on one or both surfaces. If damage occurs, it is construction or surface treatments that are less prone to fretting
quantified as a wear volume on each member and as system damageforapplicationswherefrettingconditionsareknownor
wear, the sum of the rider and counterface wear. perceived to exist.
G204 − 10
FIG. 2 Fretting Test Specimens
A = counterface
B = rider (a ball may be adhered to a pin to make the rider)
Surface roughness of both specimens = < 0.1 µm Ra
6. Apparatus frequencies usually require piezocrystals or the like as a source
of oscillation. The standard test was developed using mechani-
6.1 Fig. 1 is a schematic of the test apparatus showing
cal activation (electric motor driven crank).
necessary features. The schematic shows the counterface
moving laterally with respect to the rider. The rider could
NOTE 1—This frequency was chosen for convenience. It produces 10
cycles in about 21.4 h. Users can do a test a day.
reciprocatewithrespecttothecounterfaceaslongasitstillcan
move in the downward direction to accommodate wear.
7. Test Specimens
6.2 The rider or counterface holder can be instrumented to
7.1 The test specimens used in this test method can vary in
sense friction force, but the device cannot interfere with
shape as long as the rider has a 3.17 mm radius at the point of
achieving the required relative motion between the rider and
contact and the counterface is flat within 1 µm per cm at the
counterface. Test rigs need instrumentation or a system to
pointofcontact.Thetestspecimensusedinthedevelopmentof
verify that the amplitude of oscillation is the test value of 50 6
this test method are shown in Fig. 2.
2 µm at test frequency.
7.2 Measuring wear scars with surface analysis instruments
6.3 The test specimens must be affixed to the test rig in such
can be very challenging. The standard test was developed with
a manner that their movement in specimen clamps is less than
surface roughnesses on both rider and counterface of less than
1 µm during testing.
0.1 µm Ra. Surface finish can play a role in susceptibility to
6.4 Wear in the specified test can be such that vertical fretting damage. Polished surfaces produce the most succinct
motion of the rider as wear occurs can be hundreds of wear scars. Very rough surfaces (> 1 µm Ra) may produce
micrometers.Thus,thetestrigshouldbedesignedsuchthatthe hard-to-measure scars. Sometimes, only the rider wears; some-
rider can move into the counterface at least 500 6 20 µm. times only the counterface wears; sometimes both members
wear. Test Method G99 and G133 describe wear sc
...