1、Designation: D7594 10Standard Test Method forDetermining Fretting Wear Resistance of LubricatingGreases Under High Hertzian Contact Pressures Using aHigh-Frequency, Linear-Oscillation (SRV) Test Machine1This standard is issued under the fixed designation D7594; the number immediately following the d
2、esignation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a p
3、rocedure for determining thelubricating action of greases in order to prevent “fretting” wearunder linear oscillation with associated low strokes and highHertzian contact pressures under high-frequency linear-oscillation motion using the SRV test machine. By performingadditional, nonmandatory extrem
4、e-pressure tests in accordancewith Test Method D5706, the test grease should be shown to beable to withstand a Hertzian contact pressure of at least2200 MPa without adhesive failure.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thissta
5、ndard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Refere
6、nced Documents2.1 ASTM Standards:2A295/A295M Specification for High-Carbon Anti-FrictionBearing SteelD217 Test Methods for Cone Penetration of LubricatingGreaseD4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD5706 Test Method for Determining Extreme PressureProperties of Lu
7、bricating Greases Using a High-Frequency, Linear-Oscillation (SRV) Test MachineD6425 Test Method for Measuring Friction and Wear Prop-erties of Extreme Pressure (EP) Lubricating Oils UsingSRV Test MachineD7421 Test Method for Determining Extreme PressureProperties of Lubricating Oils Using High-Freq
8、uency,Linear-Oscillation (SRV) Test MachineE45 Test Methods for Determining the Inclusion Content ofSteelG40 Terminology Relating to Wear and Erosion2.2 DIN Standards:3DIN 51834-3:2008-12 Testing of lubricants Tribologicaltest in translatory oscillation apparatus Part 3: Determi-nation of tribologic
9、al behaviour of materials in coopera-tion with lubricantsDIN 51631:1999 Special-boiling-point spirits - Require-ments and testingDIN EN ISO 683-17 Heat-treated steels, alloy steels andfree-cutting steels - Part 17: Ball and roller bearing steels(replaces DIN 17230-1980)DIN EN ISO 13565-2:1998 Geomet
10、rical Product Specifica-tions (GPS) - Surface texture: Profile method - Surfaceshaving stratified functional properties - Part 2: Heightcharacterization using the linear material ratio curve(replaces DIN 4776-1990)2.3 ISO Standards4ISO 1250:1972 Mineral solvents for paints - White spiritsand related
11、 hydrocarbon solvents3. Terminology3.1 Definitions:3.1.1 break-in, nin tribology, an initial transition processoccurring in newly established wearing contacts, often accom-panied by transients in coefficient of friction or wear rate, orboth, that are uncharacteristic of the given tribological system
12、slong-term behavior. G401This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.G0.04 on Functional Tests - Tribology.Current edition approved May 1, 2010. Published August 2010. DOI:10.1520/D7594-10.2F
13、or referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Available from Beuth Verlag GmbH (DIN- DIN Deut
14、schesInstitut fur Normung e.V.), Burggrafenstrasse 6, 10787, Berlin, Germany, http:/www.en.din.de.4Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.1Copyright ASTM International, 100 Barr
15、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.2 coeffcient of friction, or , nin tribology, thedimensionless ratio of the friction force (F) between twobodies to the normal force (N) pressing these bodies together.G403.1.3 Hertzian contact area, napparent area of con
16、tactbetween two nonconforming solid bodies pressed against eachother, as calculated from Hertz equations of elastic deforma-tion. G403.1.4 Hertzian contact pressure, nmagnitude of the pres-sure at any specified location in a Hertzian contact area, ascalculated from Hertz equations of elastic deforma
17、tion. G403.1.5 lubricant, nany material interposed between twosurfaces that reduces the friction or wear between them.D41753.1.6 lubricating grease, na semifluid to solid product ofa dispersion of a thickener in a liquid lubricant. D2173.1.6.1 DiscussionThe dispersion of the thickener forms atwo-pha
18、se system and immobilizes the liquid lubricant bysurface tension and other physical forces. Other ingredients arecommonly included to impart special properties.3.1.7 Ra (C.L.A.), nin measuring surface finish, the arith-metic average of the absolute distances of all profile pointsfrom the mean line f
19、or a given distance.3.1.7.1 DiscussionC.L.A. means center line average, andit is a synonym to Ra. Amstutz, p. 2153.1.8 Rpk, nReduced peak height according to DIN ENISO 13565-2:1998. Rpk is the mean height of the peak stickingout above the core profile section.3.1.9 Rvk, nReduced valley height accord
20、ing to DIN ENISO 13565-2:1998. Rvk is the mean depth of the valleyreaching into the material below the core profile section.3.1.10 Ry, nin measuring surface finish, the verticaldistance between the top of the highest peak and the bottom ofthe deepest valley in one sampling length. Amstutz, p. 2553.1
21、.11 Rz (DIN), nin measuring surface finish, the aver-age of all Ry values (peak to valley heights) in the assessmentlength. Amstutz, pp. 29, 3153.1.12 thickener, nin lubricating grease, a substancecomposed of finely divided particles dispersed in a liquidlubricant to form the products structure. D21
22、73.1.12.1 DiscussionThe thickener can be fibers (such asvarious metallic soaps) or plates or spheres (such as certainnon-soap thickeners) which are insoluble or, at most, only veryslightly soluble in the liquid lubricant. The general require-ments are that the solid particles be extremely small, uni
23、formlydispersed, and capable of forming a relatively stable, gel-likestructure with the liquid lubricant.3.2 Definitions of Terms Specific to This Standard:3.2.1 extreme pressure, adjin lubrication, characterizedby metal surface in contact under high-stress rubbing condi-tions.3.2.2 fretting wear, n
24、wear arising as a result of fretting.Small amplitude oscillatory motion, usually tangential, be-tween two solid surfaces in contact.3.2.3 seizure, nlocalized adhesion of polymer onto metalbetween the rubbing surfaces of the test pieces.3.2.3.1 DiscussionIn this test method, seizure is indicatedby a
25、sharp rise in the coefficient of friction, over steady state,of greater than 0.2 for over 20 s, or a coefficient of friction0.35 or by any examples shown in Test Method D5706 andD7421). If any of these conditions occur, the test is not valid.(These criteria were believed to be right, because this st
26、andardis related to greases.) The evidence of adhesive wear mor-phologies should be controlled by micro-optical examinationof the wear scar and track. In severe cases, a stoppage in themotor will occur.3.2.4 SRV, nSchwingung, Reibung, Verschlei (Ger-man); oscillating, friction, wear (English transla
27、tion).4. Summary of Test Method4.1 This test method is performed on an SRV test machineusing a steel test ball oscillating under constant frequency,short stroke amplitude and under constant load (Fn), against astationary steel test disk with a grease lubricant between themin order to determine the c
28、oefficient of friction and wear scardiameter.4.2 For the non-mandatory extreme pressure test (see Ap-pendix X1), the test load is increased in 100-N increments untilseizure occurs (see Test Method D5706). The load, immedi-ately prior to the load at which seizure occurs, is measured andreported.NOTE
29、1Test frequency, stroke length, temperature, and ball and diskmaterial can be varied to simulate field conditions. The test ball yieldspoint-contact geometry. To obtain line or area contact, test pieces ofdiffering configurations can be substituted for the test balls.4.3 The friction force, Ff, is m
30、easured by a piezo-electricdevice in the test disk assembly. Peak values of coefficient offriction, f, are determined and recorded as a function of time forSRV I and II models. SRV III and IV models can display thehysteresis (Friction force or coefficient of friction over strokelength) and save test
31、 data electronically.4.4 After a preset test period, the test machine and chartrecorder stopped and the wear scar on the ball is measured. Ifa profilometer is available, a trace of the wear track on the testdisk and the wear scar of the ball (See DIN 51834-3 andAppendix X1) can also be used to obtai
32、n additional wearinformation. Wear volume in mm3and wear rate of disk andball in mm3/Nm).5. Significance and Use5.1 This test method can be used to determine anti-wearproperties and coefficient of friction of greases in order toprevent “fretting” wear under linear oscillation with associatedlow stro
33、kes and high Hertzian contact pressures at selectedtemperatures and loads specified for use in applications inwhich induced, high-speed vibrational motions are present forextended periods of time. It has found application as ascreening test for grease lubricants used in ball and rollerbearings, roll
34、er or ball screw (spindle) drives or side shaftsystems (Tripode or Rzeppa type) for example, so-calledconstant velocity (CV) joints. Users of this test method shoulddetermine whether results correlate with field performance orother applications.5Amstutz, Hu, “Surface Texture: The Parameters,” Bullet
35、in MI-TP-0030785,Sheffield Measurement Division, Warner and Swasey, 1985.D7594 1026. Apparatus6.1 SRV Test Machine6Illustrated in Fig. 1 and Fig. 2.7. Reagents and Materials7.1 Test Balls652100 steel, 60 6 2 Rc hardness, 0.025 60.005-m Ra surface finish, 10-mm diameter.7.2 Lower Test Disk6Vacuum arc
36、 remelted (VAR) AISI52100 steel with an inclusion rating using Method D, Type A,as severity level number of 0.5 in accordance with TestMethods E45 and Specification A295/A295M or an inclusionsum value K1 # 10 in accordance with DIN EN ISO 683-17and spherodized annealed to obtain globular carbide, 60
37、 6 2Rc hardness, the surfaces of the disk being lapped and free oflapping raw materials. The topography of the disk will bedetermined by four values, 24-mm diameter by 7.85 mm thick:0.5 m Rz 0.650 m0.035 m C.L.A. (Ra) 0.050 m0.020 m Rpk 0.035 m0.050 m Rvk 0.075 m7.3 Cleaning SolventThe test disks ha
38、ve to be cleaned bya liquid solvent (non-chlorinated, non-film forming). It isrecommended to use special boiling point spirit type 2-A inaccordance with DIN 51631:1999 or ISO 1250:1972.(WarningFlammable. Health hazard.).8. Preparation of Apparatus8.1 Turn on the test machine and chart recorder and a
39、llow towarm up for 15 min prior to running tests.8.2 Select the friction data to be presented in the crest peakvalue position in accordance with the manufacturers direc-tions.NOTE 2In most cases, this is accomplished by positioning the slidingswitch on electronic card NO. 291.35.20E (front side of e
40、lectronics behindthe front panel) and the sliding switch located back on the panel of thecontrol unit.8.3 Turn the amplitude knob to ZERO.8.4 Switch the stroke adjustment to AUTO position.8.5 Set the frequency to 50 Hz and duration to 4 h, 00 min,30 s in accordance with the manufacturers instruction
41、s.6The sole source of supply of the apparatus known to the committee at this timeis Optimol Instruments GmbH, Westendstr. 125, D-80339 Munich, Germany. If youare aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful cons
42、ideration at ameeting of the responsible technical committee,1which you may attend.NOTEAbove: Model III; Below: Model IVFIG. 1 SRV Test Machine1. Oscillation drive rod 6. Electrical Resistance Heater2. Test Ball Holder 7. Resistance Thermometer3. Load Rod 8. Test Disk Holder4. Test Ball 9. Piezoelec
43、tric Measuring Device5. Test Disk 10. Receiving BlockFIG. 2 Test Chamber ElementsD7594 1038.6 Set the load charge amplifier to the setting that corre-sponds to the load foreseen for the test in accordance with themanufacturers instructions. Select the desired chart speed.NOTE 3In later SRV models, t
44、he load charge amplifier is set auto-matically.9. Procedure9.1 Installation of the Test Pieces and Lubricating OilSpecimen in the Test Chamber:9.1.1 Using solvent resistant gloves, clean the test ball, ballholder, and disk by wiping the surfaces with laboratory tissuesoaked with the cleaning solvent
45、 (single boiling point spirittype 2-A in accordance with DIN 51631:1999.(WarningThis mixture is flammable and health hazard.) Repeat wipinguntil no dark residue appears on the tissue. Immerse the testball and disk in a beaker of the cleaning solvent underultrasonic vibration for 10 min. Dry the test
46、 ball and disk witha clean tissue to ensure no streaking occurs on the surface.9.1.2 Ensure that the machine is unloaded (indicated by aload reading of 13 or 14N), and install the ball holder (upperspecimen holder).9.1.3 Place the grease caliper with 1 mm in height on thecleaned disc. Fill the openi
47、ng of the grease caliper with grease.Remove any excess grease by means of a spatula. Remove thegrease caliper by lifting it upwards. Fasten the disc in thespecimen holder.9.1.4 Place the cleaned test ball on the top and in the middleof the lubricating grease specimen so that the lubricating greasema
48、kes a circular symmetric pad between the test ball and disk.9.1.5 Tighten the fastening screw until resistance just be-gins.9.2 Test Run:9.2.1 Start of the Test RunTurn on the heater control, andpreheat the disk holder to 50C. Allow 10 min for the testpieces and test grease to reach and stabilize at
49、 the testtemperature. The test can be run at constant temperaturesselected in +10 K (+10C) increments starting at +233K to+423K (-40C to +150C).NOTE 4An initial hardness of 62.5 HRC at room temperature of AISI52100 will drop to 61 HRC after 100 h at 149C and will exist as a hothardness of 60 HRC over 100 h.79.2.2 Apply a load of 50 N, loosen the fastening screws onboth disk and ball holders, and then immediately tighten themwith a torque wrench to 2.2 to 2.5 Nm.9.2.3 When the temperature has stabilized, turn on th
