ASTM D2981-94(2009)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D2981 − 94(Reapproved 2009)
Standard Test Method for
Wear Life of Solid Film Lubricants in Oscillating Motion
This standard is issued under the fixed designation D2981; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.4 wear—damage to a solid surface, generally involving
progressive loss of material, due to relative motion between
1.1 This test method covers the evaluation of wear life of a
that surface and a contacting substance or substances.
bonded solid film lubricant under oscillating motion by means
of a block-on-ring friction and wear testing machine.
4. Summary of Test Method
1.2 This standard does not purport to address all of the
4.1 The test machine is operated using a coated steel testing
safety concerns, if any, associated with its use. It is the
ring oscillating against a steel test block. The oscillating speed
responsibility of the user of this standard to establish appro-
is 87.5 6 1 cpm at a 90° arc. The specimens are worn-in for 1
priate safety and health practices and determine the applica-
min at 13.6 kg (30 lb) normal load obtained by application of
bility of regulatory limitations prior to use.
0.454 kg (1 lb) of dead weight to the 0:1 ratio lever system.
Wear-in is followed by application of a normal load of 283 kg
2. Referenced Documents
(630 lb) obtained by application of 9.53 kg (21 lb) of dead
2.1 ASTM Standards: weighttothe30:1ratioleversystemforthedurationofthetest.
D2714Test Method for Calibration and Operation of the
4.2 One measurement is made:
Falex Block-on-Ring Friction and Wear Testing Machine
4.2.1 wear life—the number of cycles required for the
frictional force to rise to a predetermined value.
3. Terminology
5. Significance and Use
3.1 Definitions:
3.1.1 coeffıcient of friction, µ or f—in tribology, the dimen- 5.1 This test method is used for determining the wear life
sionlessratioofthefrictionforce(F)betweentwobodiestothe properties of bonded solid lubricants in oscillating motion
normal force (N) pressing these two bodies together. under the prescribed test conditions. This test method differ-
entiates between bonded solid lubricants with respect to their
µ or f 5 F/N (1)
~ !
wear life. If the test conditions are changed, relative wear life
3.1.1.1 Discussion—A distinction is often made between
may change and relative ratings of the bonded solid film
static coeffıcient of friction and kinetic coeffıcient of friction.
lubricants may be different.
3.1.2 friction force—the resisting force tangential to the
interface between two bodies when, under the action of an
6. Apparatus
externalforce,onebodymovesortendstomoverelativetothe
6.1 Block-on-Ring Test Machine, equippedwithoscillating
other.
drive, load cell transducer and recorder described in detail in
3.1.3 kinetic coeffıcient of friction—the coefficient of fric-
AnnexA1 and illustrated in Fig. 1. (See Test Method D2714.)
tion under conditions of macroscopic relative motion between
6.2 Test Ring, SAE 4620 Steel, having a Rockwell hardness
two bodies.
of HRC 58-63. Each ring had a ground face of 8.163 mm 6
0.127 mm (0.321 6 0.005 in.), a diameter of 34.9885 6
0.0254,− 0.1270 mm (1.3775 6 0.001,−0.005 in.) and an
This test method is under the jurisdiction of ASTM Committee D02 on
eccentricitybetweentheinnerandoutersurfaceof 60.038mm
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
(0.0015 in.). The surface finish of the outside diameter of each
D02.L0.05 on Solid Lubricants.
ring prior to lubricant coating application should be from 500
Current edition approved April 15, 2009. Published July 2009. Originally
approved in 1971. Last previous edition approved in 2003 as D2981–94 (2003). to 750 nm (20 to 30 µin.) rms.
DOI: 10.1520/D2981-94R09.
2 5
2 6.3 Test Block, SAE 01 Steel with test surface of 0.635 6
The Block-on-Ring Test machine is available from Falex Corp., 1020 Airpark
Dr., Sugar Grove, IL 60554. 0.021,−0.000 mm (0.250 6 0.0005,−0.0000 in.) wide and
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from Falex Corp., 1020 Airpark Dr., Sugar Grove, IL 60554.
the ASTM website. SAE 01 is also known as Starrett 406 or Marshall Oilcrat.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2981 − 94 (2009)
9.2 With 1.4 kg (3 lb) on the bale rod, which is equivalent
to a 13.6 kg (30 lb) normal load on the specimen, start the
machine. Standard drive machines will operate only at 87.5
cpm; for variable drive units the 87.5 cpm speed is set before
specimens are mounted. Run the machine for 1 min to
accomplishinitialwear-inofthecoatedspecimenandthenstop
the machine. Gently lower 27.3 kg (60 lb) of additional weight
onto the bale rod, bringing the total to 28.3 kg (63 lb) or 283
kg (630 lb) normal load on the specimen. Start the machine
again and run until failure occurs due to excessive friction, as
described above. Record friction during the break-in cycle and
also record the number of revolutions to failure.
FIG. 1 Falex Block-on-Ring Test Machine with Recorder
10. Calculation
10.1 Calculate the coefficient of friction from the friction
1.575 6 0.005 mm (0.620 6 0.0002 in.) long and having a
force values as follows:
Rockwell hardness of HRC 58-63. Each block should have the
f 5 F/W (2)
test surface ground to a finish of 100 to 200 nm (4 to 8 µin.)
rms and be perfectly square with all outside edges.
where:
f = coefficient of friction,
7. Reagents
F = friction force, kg (lb), and
7.1 Solvents, safe, nonfilming, nonchlorinated.
W = normal load, kg (lb).
11. Report
8. Preparation of Apparatus
11.1 The report shall include the following:
8.1 Before each test, thoroughly clean the test block, the
11.1.1 Reportthefrictionforceinbothdirectionsat50,100,
shaft, specimen holder, lock nut, lock washer, and the tapered
and 1000 cycles. Record the number of revolutions to failure,
and threaded sections of the test shaft, using the solvents
(point after wear-in at which a coefficient of friction of 0.1 is
described in 6.1.
reached).
8.2 Usingclean,lint-freecottongloves,mountthetestblock
11.1.2 Indicate where failure occurred, whether in the in-
intheblockholderandpositionbothsecurelyinthecylindrical
side, middle, or outside of the wear track of the test ring.
slot of the specimen holder. Holding the test block in place,
mount the test ring over the test shaft and press into position 12. Preci
...