1、Designation: D 2981 94 (Reapproved 2003)An American National StandardStandard Test Method forWear Life of Solid Film Lubricants in Oscillating Motion1This standard is issued under the fixed designation D 2981; the number immediately following the designation indicates the year oforiginal adoption or
2、, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the evaluation of wear life of abonded solid film lubr
3、icant under oscillating motion by meansof a block-on-ring2friction and wear testing machine.1.2 The values stated in either inch-pound units or SI(metric) units are to be regarded separately as standard. Withinthe text the SI units are shown in brackets. The values stated ineach system are not exact
4、 equivalents, therefore each systemmust be used independently of the other. Combining values ofthe two systems may result in nonconformance with thespecification.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the u
5、ser of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D 2714 Test Method for Calibration and Operation of theFalex Block-on-Ring Friction and Wear Test Machine3. Te
6、rminology3.1 Definitions:3.1.1 coeffcient of friction, or fin tribology, the dimen-sionless ratio of the friction force (F) between two bodies to thenormal force (N) pressing these two bodies together. or f 5 F/N! (1)3.1.1.1 DiscussionA distinction is often made betweenstatic coeffcient of friction
7、and kinetic coeffcient of friction.3.1.2 friction forcethe resisting force tangential to theinterface between two bodies when, under the action of anexternal force, one body moves or tends to move relative to theother.3.1.3 kinetic coeffcient of frictionthe coefficient of fric-tion under conditions
8、of macroscopic relative motion betweentwo bodies.3.1.4 weardamage to a solid surface, generally involvingprogressive loss of material, due to relative motion betweenthat surface and a contacting substance or substances.4. Summary of Test Method4.1 The test machine is operated using a coated steel te
9、stingring oscillating against a steel test block. The oscillating speedis 87.5 6 1 cpm at a 90 arc. The specimens are worn-in for 1min at 13.6 kg (30 lb) normal load obtained by application of0.454 kg (1 lb) of dead weight to the 0:1 ratio lever system.Wear-in is followed by application of a normal
10、load of 283 kg(630 lb) obtained by application of 9.53 kg (21 lb) of deadweight to the 30:1 ratio lever system for the duration of the test.4.2 One measurement is made:4.2.1 wear lifethe number of cycles required for thefrictional force to rise to a predetermined value.5. Significance and Use5.1 Thi
11、s test method is used for determining the wear lifeproperties of bonded solid lubricants in oscillating motionunder the prescribed test conditions. This test method differ-entiates between bonded solid lubricants with respect to theirwear life. If the test conditions are changed, relative wear lifem
12、ay change and relative ratings of the bonded solid filmlubricants may be different.6. Apparatus6.1 Block-on-Ring Test Machine,2equipped with oscillatingdrive, load cell transducer and recorder described in detail inAnnex A1 and illustrated in Fig. 1. (See Test Method D 2714.)6.2 Test Ring,4SAE 4620
13、Steel, having a Rockwell hardnessof HRC 58-63. Each ring had a ground face of 8.163 mm 61This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.L0 on Industrial Lubricants.Current edition approved Nov.
14、1, 2003. Published November 2003. Originallyapproved in 1971. Last previous edition approved in 1998 as D 298194 (1998).2The Block-on-Ring Test machine is available from Falex Corp., 1020 AirparkDr., Sugar Grove, IL 60554.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontac
15、t ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from Falex Corp., 1020 Airpark Dr., Sugar Grove, IL 60554.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes
16、t Conshohocken, PA 19428-2959, United States.0.127 mm (0.321 6 0.005 in.), a diameter of 34.9885 60.0254, 0.1270 mm (1.3775 6 0.001, 0.005 in.) and aneccentricity between the inner and outer surface of 60.038 mm(0.0015 in.). The surface finish of the outside diameter of eachring prior to lubricant c
17、oating application should be from 500to 750 nm (20 to 30 in.) rms.6.3 Test Block,2SAE 01 Steel5with test surface of 0.635 60.021, 0.000 mm (0.250 6 0.0005, 0.0000 in.) wide and1.575 6 0.005 mm (0.620 6 0.0002 in.) long and having aRockwell hardness of HRC 58-63. Each block should have thetest surfac
18、e ground to a finish of 100 to 200 nm (4 to 8 in.)rms and be perfectly square with all outside edges.7. Reagents7.1 Solvents,6safe, nonfilming, nonchlorinated.8. Preparation of Apparatus8.1 Before each test, thoroughly clean the test block, theshaft, specimen holder, lock nut, lock washer, and the t
19、aperedand threaded sections of the test shaft, using the solventsdescribed in 6.1.8.2 Using clean, lint-free cotton gloves, mount the test blockin the block holder and position both securely in the cylindricalslot of the specimen holder. Holding the test block in place,mount the test ring over the t
20、est shaft and press into positionbeneath the block exercising care not to scratch the coated testsurface. Position the lock washer and lock nut and tighten withthe torque wrench to 2 Nm (100 lbin.)8.3 Calibrate the load cell transducer and recorder in accor-dance with the equipment manufacturers dir
21、ections.8.4 Adjust the arc of oscillation to 90.8.5 Place a 1.4 kg (3 lb) weight in position on the bale rod.8.6 Set the friction force cut-off level to terminate the test ata frictional force of 280 N (63 lb) or a coefficient of friction of0.1 after wear-in.9. Procedure9.1 Conduct the test in a tem
22、perature- and humidity-controlled atmosphere (24 6 3C (75 6 5F), 50 6 5 %) andallow sufficient static time for the specimens to reach a state ofequilibrium.9.2 With 1.4 kg (3 lb) on the bale rod, which is equivalentto a 13.6 kg (30 lb) normal load on the specimen, start themachine. Standard drive ma
23、chines will operate only at 87.5cpm; for variable drive units the 87.5 cpm speed is set beforespecimens are mounted. Run the machine for 1 min toaccomplish initial wear-in of the coated specimen and then stopthe machine. Gently lower 27.3 kg (60 lb) of additional weightonto the bale rod, bringing th
24、e total to 28.3 kg (63 lb) or 283kg (630 lb) normal load on the specimen. Start the machineagain and run until failure occurs due to excessive friction, asdescribed above. Record friction during the break-in cycle andalso record the number of revolutions to failure.10. Calculation10.1 Calculate the
25、coefficient of friction from the frictionforce values as follows:f 5 F/W (2)where:f = coefficient of friction,F = friction force, kg (lb), andW = normal load, kg (lb).11. Report11.1 The report shall include the following:11.1.1 Report the friction force in both directions at 50, 100,and 1000 cycles.
26、 Record the number of revolutions to failure,(point after wear-in at which a coefficient of friction of 0.1 isreached).11.1.2 Indicate where failure occurred, whether in the in-side, middle, or outside of the wear track of the test ring.12. Precision and Bias12.1 PrecisionThe following criteria shou
27、ld be used forjudging the acceptability of test results (95 % probability).12.1.1 Wear Life Measurement:12.1.1.1 RepeatabilityThe difference between successivetest results, obtained by the same operator with the sameapparatus under constant operating conditions on identical testmaterial would, in th
28、e long run, and in the normal and correctoperation of the test method, exceed 25 % of the mean only inone case in twenty.12.1.1.2 ReproducibilityThe difference between two,single and independent results, obtained by different operatorsworking in different laboratories on identical test materialwould
29、, in the long run, and in the normal and correct operationof the test method, exceed 33 % of the mean only in one casein twenty.12.2 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedure in TestMethod D 2981 for measuring wear life, no statement on bias
30、is being made.5SAE 01 is also known as Starrett 406 or Marshall Oilcrat.6Benzene, n-hexane or isooctane, formerly used in this test method, has beeneliminated due to possible toxic effects. Though it is not expected that there will beany adverse influence on results, principal users will advise expe
31、riences to guidefuture work.FIG. 1 Falex Block-on-Ring Test Machine with RecorderD 2981 94 (2003)213. Keywords13.1 oscillating; solid film lubricant; wear frictionANNEX(Mandatory Information)A1. DESCRIPTION OF THE FALEX BLOCK-ON-RING TEST MACHINEA1.1 A stationary rectangular test block bears under a
32、predetermined load, maximum 548 kg (1300 lb), against arotating (or oscillating) ring. The load is accurately maintainedthroughout the test. Bearing pressures (average Hertz pres-sures) in the line contact area between the rectangular speci-men and the rotating ring may range up to 110 000 psi (759M
33、N/m2).A1.2 In rotational motion, friction is indicated throughoutthe test by a digital indicator. A load cell transducer and arecorder are used to obtain friction readings under oscillatingmotion. A counter records the number of revolutions or cyclesof the test ring. One criterion of failure is when
34、 the frictionreaches a pre-selected maximum. For this purpose a control onthe friction indicator or recorder can be set for any pre-selectedvalue of friction and the machine will automatically shut offupon reaching it.A1.3 In an alternative method, a thermocouple is imbeddedin the test block and a t
35、emperature controller terminates the testwhen the temperature of the test block reaches a previously setvalue.A1.4 The test shaft of the machine is supported by tworoller bearings and the mandrel end of the shaft protrudesthrough the front panel of the machine where the test speci-mens are mounted.
36、The test block, which is held stationaryagainst the rotating or oscillating ring, is restrained fromhorizontal movement by a unique type of holder. The design ofthis specimen holder allows the test block to align itselfautomatically in a manner prescribed by ASTM specificationsfor compression loaded
37、 specimens. This maintains uniformloading throughout the area of contact between the specimensregardless of the force existing between them. In oscillatingtests, the holder for the stationary specimen is mounted on aspecial friction pin assembly. This assembly is connected to aload cell which is in
38、turn connected to a digital friction meterand a recorder that monitors and records friction.A1.5 The normal force between the test specimens isproduced by suspending dead weights from the end of a leversystem which is designed in such a way as to allow the fullvalue of the friction force to be trans
39、mitted to the frictionalload pick-up device.A1.6 Speed ranges with variable speed control are availablefrom 0.5 to 7200 rpm. Fluid lubricants can be tested up to amaximum of 204C (400F). With optional equipment, the testchamber can be pressurized to 1.03 MPa (150 psi) run inspecial atmospheres or ru
40、n in vacuum.A1.7 The friction force indicator used in rotational testingis direct reading in kilograms or pounds and is fitted with aninfinitely adjustable limit control which allows the operator topreset the value of friction at which the machine will stop. Thesetting is accomplished by presetting
41、the desired value on theautomatic friction cut-off. In oscillating testing, the frictionforce-recorder system provides friction readings in both direc-tions.A1.8 A six-digit revolution counter is mounted in the digitalinstrumentation system. It is electronically actuated from thetest shaft and is eq
42、uipped with a reset.A1.9 The machine is furnished complete with all electricalequipment ready to operate after removal of a few shippingbolts. In addition to the motor, the electrical equipmentincludes control circuit relays and a push-button-controlledmagnetic motor starter for electrical overload
43、and low-voltageprotection.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infrin
44、gement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard
45、 or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views
46、 known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 2981 94 (2003)3
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