1、Designation: D 7421 08An American National StandardStandard Test Method forDetermining Extreme Pressure Properties of LubricatingOils Using High-Frequency, Linear-Oscillation (SRV) TestMachine1This standard is issued under the fixed designation D 7421; the number immediately following the designatio
2、n 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a procedure
3、 for determiningextreme pressure properties of lubricating oils for hydraulics,gears and engines under high-frequency linear-oscillation mo-tion using the SRV test machine.NOTE 1This test method was developed and the international roundrobin tests were jointly performed with the DIN 51834 working gr
4、oup.This procedure is based on the 2005 revision of Test Method D 5706 forgreases and differs regarding the stroke length and the cleaning solvent.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not p
5、urport 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. Referenced Documents2.1 ASTM Standards:2
6、A 295/A 295M Specification for High-CarbonAnti-FrictionBearing SteelD 235 Specification for Mineral Spirits (Petroleum Spirits)(Hydrocarbon Dry Cleaning Solvent)D 4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD 5706 Test Method for Determining Extreme PressureProperties of
7、 Lubricating Greases Using a High-Frequency, Linear-Oscillation (SRV) Test MachineD 6425 Test Method for Measuring Friction and WearProperties of Extreme Pressure (EP) Lubricating OilsUsing SRV Test MachineE45 Test Methods for Determining the Inclusion Contentof SteelG40 Terminology Relating to Wear
8、 and Erosion2.2 DIN Standards:3DIN 51631:1999 Mineral spirits; special boiling point spir-its; requirementsDIN 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 Geometrical Product Specifica
9、-tions (GPS) Surface texture: Profile method; Surfaceshaving stratified functional properties Part 2: Heightcharacterization using linear material ratio curve Re-placement of DIN 4776:1990: Measurement of surfaceroughness; parameters RK,RPK,RVK,Mr1,Mr2for thedescription of the material portion2.3 IS
10、O Standards:4ISO 1250:1972 Mineral solvents for paints, white spiritsand related 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
11、or wear rate, orboth, which are uncharacteristic of the given tribologicalsystems long-term behavior. G403.1.2 coeffcient of friction, orf,nin tribology, thedimensionless ratio of the friction force (F) between twobodies to the normal force (N) pressing these bodies together.G403.1.3 Hertzian contac
12、t area, napparent area of contactbetween two nonconforming solid bodies pressed against eachother, as calculated from Hertzs equations of elastic deforma-tion published in 1881. G401This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct
13、 responsibility of SubcommitteeD02.L0 on Industrial Lubricants.Current edition approved Feb. 1, 2008. Published March 2008.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, re
14、fer to the standards Document Summary page onthe ASTM website.3Available from Beuth Verlag GmbH (DIN, Deutsches Institut fur Normunge.V.), Burggrafenstrasse 6, 10787, Berlin, Germany, http:/www.en.din.de.4Available from International Organization for Standardization (ISO), 1 rue deVaremb, Case posta
15、le 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.4 Hertzian contact pressure, nmagnitude of the pres-sure at any specified location in a Hertzian contact area, ascalculated
16、from Hertzs equations of elastic deformation. TheHertzian contact pressure can also be calculated and reportedas maximum value Pmaxin the centre of the contact or asPaverageas average over the total contact area. G403.1.5 lubricant, nany material interposed between twosurfaces that reduces the frict
17、ion or wear, or both betweenthem. D 41753.1.6 Ra (C.L.A.), nin measuring surface finish, the arith-metic average of the absolute distances of all profile pointsfrom the mean line for a given distance. Amstutz53.1.6.1 DiscussionC.L.A. means center line average, andit is the synonym to Ra.3.1.7 Rpk, n
18、Reduced peak height according to DIN ENISO 13565-2:1998. Rpk is the mean height of the peak stickingout above the core profile section.3.1.8 Rvk, nReduced valley height according to DIN ENISO 13565-2:1998. Rvk is the mean depth of the valleyreaching into the material below the core profile section.3
19、.1.9 Ry, nin measuring surface finish, the vertical dis-tance between the top of the highest peak and the bottom of thedeepest valley in one sampling length. Amstutz53.1.10 Rz (DIN), nin measuring surface finish, the aver-age of all Ry values (peak to valley heights) in the assessmentlength. Amstutz
20、53.2 Definitions of Terms Specific to This Standard:3.2.1 extreme pressure, adjin lubrication, characterizedby metal surfaces in contact under high-stress rubbing condi-tions. It is not limited to metallic materials.3.2.2 seizure, nlocalized fusion of metal or other materi-als between the rubbing su
21、rfaces of the test pieces.3.2.2.1 DiscussionIn this test method, seizure is indicatedby a sharp rise in the coefficient of friction, over steady state,of 0.2 for over 20 s. In severe cases, a stoppage in the motorwill occur. (These criteria were believed to be right, becausethis test method is relat
22、ed to liquid lubricants.)3.2.3 SRV, nSchwingung, Reibung, Verschlei (Ger-man); oscillating, friction, wear (English translation).4. Summary of Test Method4.1 This test method is performed on an SRV test machineusing a steel test ball oscillating against a stationary steel testdisk with lubricant bet
23、ween them. Test load is increased in100-N increments until seizure occurs. The load, immediatelyprior to the load at which seizure occurs, is measured andreported as O.K.-load, which can be converted in Hertziancontact pressures.NOTE 2Test frequency, stroke length, temperature, and ball and diskmate
24、rial 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.NOTE 3With regard to the test chamber and the operating conditions,SRV models III and IV are ident
25、ical. However, the SRV IV allows toincline the axis of movement. Both models are fully computer controlled.In SRV IV models, the test described here is run horizontally and withoutinclination. SRV I and II models can also perform this test, but they arelimited with regard to maximum load and stroke.
26、 As modern and highperformance oils may exceed an O.K.-load of 1200 N, seizure may not bereached. Optimol Instruments supplies an upgrade kit to allow for SRV Iand SRV II models to be operated at 1600 N, if needed.65. Significance and Use5.1 This laboratory test method can be used to quicklydetermin
27、e extreme pressure properties of lubricating oils atselected temperatures specified for use in applications wherenot only high-speed vibrational or start-stop motions arepresent with high Hertzian point contact. This test method hasfound wide application in qualifying lubricating oils used inconstan
28、t velocity joints of front-wheel-drive automobiles, gear-hydraulic circuit, rear axles, gears and engine components.Users of this test method should determine whether resultscorrelate with field performance or other applications.6. Apparatus6.1 SRV Test Machine,6illustrated in Figs. 1-3.6.2 Test Bal
29、ls,652100 steel, 60 6 2 Rc hardness, 0.025 60.005-m Ra surface finish, 10-mm diameter.6.3 Lower Test Disk,6vacuum arc remelted (VAR) AISI52100 steel with a inclusion rating using Method D, Type A,and a severity level number of 0.5 according to SpecificationA 295/A 295M or Test Methods E45or an inclu
30、sion sum valueK1 # 10 in accordance with DIN EN ISO 683-17 andspherodized annealed to obtain globular carbide, 60 6 2Rchardness, with 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:5
31、Amstutz, Hu, “Surface Texture: The Parameters,” Bulletin MI-TP-003-0785,Sheffield Measurement Division, Warner and Swasey, 1985.6The 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 alt
32、ernative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.FIG. 1 SRV Test Machine (Model III)D74210820.5 m Rz 0.650 m0.035 m C.L.A. (Ra) 0.050 m0.020
33、 m Rpk 0.035 m0.050 m Rvk 0.075 m7. Reagents and Materials7.1 Cleaning Solventsingle boiling point spirit type 2-Aaccording to DIN 51631:1999 or ISO 1250:1972.(WarningFlammable. Health hazard.)NOTE 4In the case of unavailability, please refer to SpecificationD 235 regarding Type I, Class B, mineral
34、spirits.8. Preparation of ApparatusPreparation of SRV I and II models8.1 Turn on the test machine and chart recorder and allow 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.NOT
35、E 5In most cases, this is accomplished by positioning the slidingswitch on electronic card NO. 291.35.20E (front side of electronics 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
36、 position.8.5 Set the frequency to 50 Hz.8.6 Set the desired span and calibrate the chart recorder inaccordance with the manufacturers instructions. Select thedesired chart speed.8.7 Turn on the heater control, and preheat the disk holder tothe desired temperature. 50C, 80C, and 120C are recom-mende
37、d (see Table 1). When the temperature has stabilized,turn on the chart recorder and depress the drive start toggleswitch until the timer begins to count and then adjust the strokeamplitude knob to 2.00 mm.8.8 Set the load charge amplifier to setting that correspondsto the 400-N load.8.9 Change the l
38、oad charge amplifier at each load inaccordance with the manufacturers instructions when thecoefficient of friction at each test load is to be studied.8.10 When the digital timer reaches 30 s, increase the loadto 100 N using the slow ramp speed rate, and maintain this loadfor 15 min.8.11 The 15-min i
39、nterval includes the loading ramp se-quence. The load has to be increase by 100 N every 2 min usingthe slow ramp until a load of 1200 N is reached, or the loadlimit of the test apparatus is attained, or failure occurs. Failureis indicated by a rise in coefficient of friction of greater than 0.2over
40、steady state for over 20 s or a stoppage in the oscillatingof the test machine (see Test Method D 5706 or D 6425.NOTE 6Because a 30-s break-in at 50 N is used, the load increasetimes will occur on the half minute of even minutes.8.12 When the 1200-N load run or maximum load of the testapparatus is c
41、ompleted or failure occurs, turn off the heatercontrol, release the load to minimum setting, (typically 13 or14 N), and remove the test ball, disk, and lubricating oil testspecimen.Preparation of SRV III and IV models8.13 When using SRV III and SRV IV models, clean andinstall the specimens as specif
42、ied under 9.1 to 9.7. Turn on thetest machine or the PC and allow to warm up for 15 min priorto running tests. The test parameters (Frequency = 50 Hz, testtemperature, stroke = 2 mm) are to be entered via the controlsoftware. The test will be run automatically. Test results(coefficient of friction,
43、normal load, total, linear wear length,sample temperature) will be displayed and saved.8.14 Generate a dynamic test program with the followingtest parameters. In this dynamic test program, the maximumload range should be set to a maximum of 2000 N.Frequency: 50 HzTest temperature: for example, 50C,
44、80C, or 120CStroke: 2 mmLoad 50 N for 30 s, then apply a load increment of 100 Nfor 15 min.After that, apply a load increment of 100 N every 2 min.9. Procedure for All SRV Models9.1 Using solvent resistant gloves, clean the test ball anddisk by wiping the surfaces with laboratory tissue soaked witht
45、he cleaning solvent. Repeat wiping until no dark residueFIG. 2 SRV Test Machine (Model IV)D7421083appears on the tissue. 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 nostreaking occurs
46、 on the surface.9.2 Ensure that the machine is unloaded (indicated by a loadreading of 13 or 14N), and install the ball holder (upperspecimen holder).9.3 Then install the disk (place on the block). Tighten thefastening screw until resistance just begins.9.4 Place the cleaned ball, using the tweezers
47、, in thedisassembled, cleaned, and dried ball holder. Tighten thefastening screw until resistance just begins. Install the ballholder, and test ball in the test chamber.9.5 Tighten both the ball and disk clamps until resistance totightening just begins. Then load unit to 100 N and tighten theball an
48、d disk clamps to a torque of 2.5 Nm. Reduce the loadto 50 N for break-in.9.6 Place 0.3 mL of the lubricating oil to be tested on thecleaned disk in to the center.9.7 Turn on the heater control or set the temperature valuein the software, and preheat the disk holder to the desiredtemperature. 50C, 80
49、C, and 120C are recommended (seeTable 1).10. Report10.1 Report the following information:10.1.1 Temperature, C,10.1.2 Stroke, mm,10.1.3 Frequency, Hz,10.1.4 Test ball material,10.1.5 Test disk material, and10.1.6 Lubricating oil test specimen (internal code or des-ignation name, brand name, performance level).10.2 Report the highest test load (pass/O.K.-load) at whichno seizure occurred and when required by specification,include a copy of the friction recording (sample recordingchart), which is generally recommended.NO
