1、Designation:D759410 Designation: D7594 11Standard 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 immedia
2、tely following the designation 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. Scope*1.1 This t
3、est method covers a procedure for determining the lubricating action of greases in order to prevent “fretting” wearunder linear oscillation with associated low strokes and high Hertzian contact pressures under high-frequency linear-oscillationmotion using the SRV test machine. By performing addition
4、al, nonmandatory extreme-pressure tests in accordance with TestMethod D5706, the test grease should be shown to be able to withstand a Hertzian contact pressure of at least 2200 MPa withoutadhesive failure.1.2 The values stated in SI units are to be regarded as standard. No other units of measuremen
5、t are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitation
6、s prior to use.2. Referenced Documents2.1 ASTM Standards:2A295/A295M Specification for High-Carbon Anti-Friction Bearing SteelD217 Test Methods for Cone Penetration of Lubricating GreaseD4175 Terminology Relating to Petroleum, Petroleum Products, and LubricantsD5706 Test Method for Determining Extre
7、me Pressure Properties of Lubricating Greases Using a High-Frequency,Linear-Oscillation (SRV) Test MachineD6425 Test Method for Measuring Friction and Wear Properties of Extreme Pressure (EP) Lubricating Oils Using SRV TestMachineD7421 Test Method for Determining Extreme Pressure Properties of Lubri
8、cating Oils Using High-Frequency, Linear-Oscillation (SRV) Test MachineE45 Test Methods for Determining the Inclusion Content of SteelG40 Terminology Relating to Wear and Erosion2.2 DIN Standards:3DIN 51834-3:2008-12 Testing of lubricants Tribological test in translatory oscillation apparatus Part 3
9、: Determination oftribological behaviour of materials in cooperation with lubricantsDIN 51631:1999 Special-boiling-point spirits - Requirements and testingDIN EN ISO 683-17 Heat-treated steels, alloy steels and free-cutting steels - Part 17: Ball and roller bearing steels (replacesDIN 17230-1980)DIN
10、 EN ISO 13565-2:1998 Geometrical Product Specifications (GPS) - Surface texture: Profile method - Surfaces havingstratified functional properties - Part 2: Height characterization using the linear material ratio curve (replaces DIN 4776-1990)2.3 ISO StandardsISO 1250:1972 Mineral solvents for paints
11、 - White spirits and related hydrocarbon solvents1This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.G0.04on Functional Tests - Tribology.Current edition approved May 1, 2010. Published August 201
12、0. DOI:10.1520/D7594-10.Current edition approved Dec. 1, 2011. Published March 2012. Originally approved in 2010. Last previous edition approved in 2010 as D759410. DOI:10.1520/D7594-11.2For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm
13、.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3Available from Available from Beuth Verlag GmbH (DIN- DIN Deutsches Institut fur Normung e.V.), Burggrafenstrasse 6, 10787, Berlin, Germany, http:/www.en.din.de.1This document
14、 is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appr
15、opriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United St
16、ates.3. Terminology3.1 Definitions:3.1.1 break-in, nin tribology, an initial transition process occurring in newly established wearing contacts, often accompaniedby transients in coefficient of friction or wear rate, or both, that are uncharacteristic of the given tribological systems long-termbehav
17、ior. G40D7594 1123.1.2 coeffcient of friction, or , nin tribology, the dimensionless ratio of the friction force (F) between two bodies to thenormal force (N) pressing these bodies together. G403.1.3 Hertzian contact area, napparent area of contact between two nonconforming solid bodies pressed agai
18、nst each other,as calculated from Hertz equations of elastic deformation. G403.1.4 Hertzian contact pressure, nmagnitude of the pressure at any specified location in a Hertzian contact area, as calculatedfrom Hertz equations of elastic deformation. G40 magnitude of the pressure at any specified loca
19、tion in a Hertziancontact area, as calculated from Hertzs equations of elastic deformation. The Hertzian contact pressure can also becalculated and reported as maximum value Pmaxin the centre of the contact or as Paverageas average over the totalcontact area. D74213.1.5 lubricant, nany material inte
20、rposed between two surfaces that reduces the friction or wear between them. D41753.1.6 lubricating grease, na semifluid to solid product of a dispersion of a thickener in a liquid lubricant. D2173.1.6.1 DiscussionThe dispersion of the thickener forms a two-phase system and immobilizes the liquid lub
21、ricant by surfacetension and other physical forces. Other ingredients are commonly included to impart special properties.3.1.7 Ra (C.L.A.), nin measuring surface finish, the arithmetic average of the absolute distances of all profile points from themean line for a given distance.3.1.7.1 DiscussionC.
22、L.A. means center line average, and it is a synonym to Ra. Amstutz, p. 2143.1.8 Rpk, nReduced peak height according to DIN EN ISO 13565-2:1998. Rpk is the mean height of the peak sticking outabove the core profile section.3.1.9 Rvk, nReduced valley height according to DIN EN ISO 13565-2:1998. Rvk is
23、 the mean depth of the valley reachinginto the material below the core profile section.3.1.10 Ry, nin measuring surface finish, the vertical distance between the top of the highest peak and the bottom of the deepestvalley in one sampling length. Amstutz, p. 2553.1.11Rz (DIN), nin measuring surface f
24、inish, the average of all Ry values (peak to valley heights) in the assessment length.Amstutz, pp. 29, 3143.1.123.1.11 thickener, nin lubricating grease, a substance composed of finely divided particles dispersed in a liquid lubricantto form the products structure. D2173.1.12.13.1.11.1 DiscussionThe
25、 thickener can be fibers (such as various metallic soaps) or plates or spheres (such as certain non-soapthickeners) which are insoluble or, at most, only very slightly soluble in the liquid lubricant. The general requirements are that thesolid particles be extremely small, uniformly dispersed, and c
26、apable of forming a relatively stable, gel-like structure with the liquidlubricant.3.2 Definitions of Terms Specific to This Standard:3.2.1 extreme pressure, adjin lubrication, characterized by metal surface in contact under high-stress rubbing conditions.3.2.2 fretting wear, nwear arising as a resu
27、lt of fretting. Small amplitude oscillatory motion, usually tangential, between twosolid surfaces in contact.3.2.3 seizure, nlocalized adhesionfusion of polymer onto metal between the rubbing surfaces of the test pieces. D57063.2.3.1 DiscussionIn this test method, seizure is indicated by a sharp ris
28、e in the coefficient of friction, over steady state, ofgreater than 0.2 for over 20 s, or a coefficient of friction 0.35 or by any examples shown in Test Method D5706and D7421). Ifany of these conditions occur, the test is not valid. (These criteria were believed to be right, because this standard i
29、s related togreases.) The evidence of adhesive wear morphologies should be controlled by micro-optical examination of the wear scar andtrack. In severe cases, a stoppage in the motor will occur.3.2.43.3 Abbreviations:3.3.1 SRV, nSchwingung, Reibung, Verschlei (German); oscillating, friction, wear (E
30、nglish translation).4. Summary of Test Method4.1 This test method is performed on an SRV test machine using a steel test ball oscillating under constant frequency, shortstroke amplitude and under constant load (Fn), against a stationary steel test disk with a grease lubricant between them in orderto
31、 determine the coefficient of friction and wear scar diameter.4.2 For the non-mandatory extreme pressure test (seeAppendix X1), the test load is increased in 100-N increments until seizureoccurs (see Test Method D5706). The load, immediately prior to the load at which seizure occurs, is measured and
32、 reported.NOTE 1Test frequency, stroke length, temperature, and ball and disk material can be varied to simulate field conditions. The test ball yieldspoint-contact geometry. To obtain line or area contact, test pieces of differing configurations can be substituted for the test balls.4.3 The frictio
33、n force, Ff, is measured by a piezo-electric device in the test disk assembly. Peak values of coefficient of friction,f, are determined and recorded as a function of time for SRV I and II models. SRV III and IV models can display the hysteresis4Available from International Organization for Standardi
34、zation (ISO), 1, ch. de la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.4Amstutz, Hu, “Surface Texture: The Parameters,” Bulletin MI-TP-0030785, Sheffield Measurement Division, Warner and Swasey, 1985.D7594 113(Friction force or coefficient of friction over stroke
35、length) and save test data electronically.4.4 After a preset test period, the test machine and chart recorder stopped and the wear scar on the ball is measured. If aprofilometer is available, a trace of the wear track on the test disk and the wear scar of the ball (See DIN 51834-3 and AppendixX1) ca
36、n also be used to obtain additional wear information. Wear volume in mm3and wear rate of disk and ball in mm3/Nm).5. Significance and Use5.1 This test method can be used to determine anti-wear properties and coefficient of friction of greases in order to prevent“fretting” wear under linear oscillati
37、on with associated low strokes and high Hertzian contact pressures at selected temperaturesand loads specified for use in applications in which induced, high-speed vibrational motions are present for extended periods oftime. It has found application as a screening test for grease lubricants used in
38、ball and roller bearings, roller or ball screw (spindle)drives or side shaft systems (Tripode or Rzeppa type) for example, so-called constant velocity (CV) joints. Users of this test methodshould determine whether results correlate with field performance or other applications.6. Apparatus6.1 SRV Tes
39、t Machine5Illustrated in Fig. 1 and Fig. 2.7. Reagents and Materials7.1 Test Balls552100 steel, 60 6 2 Rc hardness, 0.025 6 0.005-m Ra surface finish, 10-mm diameter.7.2 Lower Test Disk5Vacuum arc remelted (VAR) AISI 52100 steel with an inclusion rating using Method D, Type A, asseverity level numbe
40、r of 0.5 in accordance with Test Methods E45 and Specification A295/A295M or an inclusion sum value K1# 10 in accordance with DIN EN ISO 683-17 and spherodized annealed to obtain globular carbide, 60 6 2 Rc hardness, thesurfaces of the disk being lapped and free of lapping raw materials. The topogra
41、phy of the disk will be determined 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 have to be cleaned by a liquid solvent (non-chlorinated, non-film forming). It isrecommended to use sp
42、ecial boiling point spirit type 2-A in accordance with DIN 51631:1999or ISO 1250:1972. (WarningFlammable. Health hazard.).8. Preparation of Apparatus8.1 Turn on the test machine and chart recorder and allow to warm up for 15 min prior to running tests.8.2 Select the friction data to be presented in
43、the crest peak value position in accordance with the manufacturers directions.NOTE 2In most cases, this is accomplished by positioning the sliding switch on electronic card NO. 291.35.20E (front side of electronics behind thefront panel) and the sliding switch located back on the panel of the contro
44、l 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 instructions.8.6 Set the load charge amplifier to the setting that corresponds to the load foreseen for t
45、he test in accordance with themanufacturers instructions. Select the desired chart speed.NOTE 3In later SRV models, the load charge amplifier is set automatically.9. Procedure9.1 Installation of the Test Pieces and Lubricating Oil Specimen in the Test Chamber:9.1.1 Using solvent resistant gloves, cl
46、ean the test ball, ball holder, and disk by wiping the surfaces with laboratory tissue soakedwith the cleaning solvent (single boiling point spirit type 2-A in accordance with DIN 51631:1999. (WarningThis mixture isflammable and health hazard.) Repeat wiping until no dark residue appears on the tiss
47、ue. Immerse the test ball and disk in a beakerof the cleaning solvent under ultrasonic vibration for 10 min. Dry the test ball and disk with a clean tissue to ensure no streakingoccurs on the surface.9.1.2 Ensure that the machine is unloaded (indicated by a load reading of 13 or 14N), and install th
48、e ball holder (upperspecimen holder).5Amstutz, Hu, “Surface Texture: The Parameters,” Bulletin MI-TP-0030785, Sheffield Measurement Division, Warner and Swasey, 1985.5The sole source of supply of the apparatus known to the committee at this time is Optimol Instruments GmbH, Westendstr. 125, D-80339
49、Munich, Germany. If you areaware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend.D7594 1149.1.3 Place the grease caliper with 1 mm in height on the cleaned disc. Fill the opening of the grease caliper with grease.Remove any excess grease by means of a spatula. Remove the grease caliper by lifting it upwards. Fasten the disc in the specimenholder.9.1.
