1、Designation: D7421 11D7421 16Standard Test Method forDetermining Extreme Pressure Properties of LubricatingOils Using High-Frequency, Linear-Oscillation (SRV) TestMachine1This standard is issued under the fixed designation D7421; the number immediately following the designation indicates the year of
2、original 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 test method covers a procedure for determining extrem
3、e pressure properties of lubricating oils for hydraulics, gears,and engines under high-frequency linear-oscillation motion using the SRV test machine.NOTE 1This test method was developed and the international round robin tests were jointly performed with the DIN 51834 working group. Thisprocedure is
4、 based on the 2005 revision of Test Method D5706 for greases and differs regarding the stroke length and the cleaning solvent.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address al
5、l 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 regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A295/A295M Specificati
6、on for High-Carbon Anti-Friction Bearing SteelD235 Specification for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Dry Cleaning Solvent)D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and LubricantsD5706 Test Method for Determining Extreme Pressure Properties of Lubricating Grease
7、s 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 TestMachineE45 Test Methods for Determining the Inclusion Content of SteelG40 Terminology Relating to Wear and Erosion2.2 DI
8、N Standards:3DIN 51631:199951631:199904 Mineral spirits; special boiling point spirits; requirementsDIN EN ISO 683-17 Heat-treated Steels, alloy steels and free-cutting steels Part steelsPart 17 : Ball and roller bearing steels(ReplacesReplaces DIN 17230-1980)17230-1980DIN EN ISO 13565-2:1998 Geomet
9、rical Product Specifications (GPS) Surface (GPS)Surface texture: Profile method;Surfaces having stratified functional properties Part propertiesPart 2: Height characterization using linear material ratiocurve Replacement of DIN 4776:1990: Measurement of surface roughness; parameters RK, RPK, RVK, Mr
10、1, Mr2 for thedescription of the material portion3. 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, which are uncharacteristic of
11、the given tribological systems long-termbehavior. G401 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.L0 on Industrial Lubricants and Engineering Sciences of High Performance Flui
12、ds and Solids.Current edition approved Dec. 1, 2011Oct. 1, 2016. Published March 2012February 2017. Originally approved in 2008. Last previous edition approved in 20082011 asD7421D7421 11.08. DOI: 10.1520/D7421-11.10.1520/D7421-16.2 For referencedASTM standards, visit theASTM website, www.astm.org,
13、or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from Beuth Verlag GmbH (DIN, Deutsches Institut fur Normung e.V.), Burggrafenstrasse 6, 10787, Berlin, Germany, http:/
14、www.en.din.de.This document 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 con
15、sult prior editions as appropriate. 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 standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken
16、, PA 19428-2959. United States13.1.2 coeffcient of friction, or f,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 bodie
17、s pressed against each other,as calculated from Hertzs equations of elastic deformation published in 1881. G403.1.4 Hertzian contact pressure, nmagnitude of the pressure at any specified location in a Hertzian contact area, as calculatedfrom Hertzs equations of elastic deformation. The Hertzian cont
18、act pressure can also be calculated and reported as maximumvalue Pmax in the centre of the contact or as Paverage as average over the total contact area. G40D41753.1.5 lubricant, nany material interposed between two surfaces that reduces the friction or wear, or both between them. D41753.1.6 Ra (C.L
19、.A.), nin measuring surface finish, the arithmetic average of the absolute distances of all profile points from themean line for a given distance.4 Amstutz 43.1.6.1 DiscussionC.L.A. means center line average, and it is the synonym to Ra.3.1.7 Rpk, nReduced peak height according to DIN EN ISO 13565-2
20、:1998. Rpk is the mean height of the peak sticking outabove the core profile section.3.1.8 Rvk, nReduced valley height according to DIN EN ISO 13565-2:1998. Rvk is the mean depth of the valley reachinginto the material below the core profile section.3.1.9 Rz (DIN), nin measuring surface finish, the
21、average of all Ry values (peak to valley heights) in the assessment length.4Amstutz 43.2 Definitions of Terms Specific to This Standard:3.2.1 extreme pressure, adjin lubrication, characterized by metal surfaces in contact under high-stress rubbing conditions. Itis not limited to metallic materials.3
22、.2.2 seizure, nlocalized fusion of metal between the rubbing surfaces of the test pieces. D57063.2.2.1 DiscussionIn this test method, seizure is indicated by a sharp rise in the coefficient of friction, over steady state, of 0.2 for over 20 s. 20 s.In severe cases, a stoppage in the motor will occur
23、. (These criteria were believed to be right, because this test method is relatedto liquid lubricants.)3.3 Abbreviations:3.3.1 SRV, nSSchwingung,chwingung, RReibung,eibung, VVerschlei erschlei (German); oscillating, friction, wear (Englishtranslation).4. Summary of Test Method4.1 This test method is
24、performed on an SRV test machine using a steel test ball oscillating against a stationary steel test diskwith lubricant between them. Test load is increased in 100-N100 N increments until seizure occurs. The load, immediately priorto the load at which seizure occurs, is measured and reported as O.K.
25、-load, which can be converted in Hertzian contact pressures.NOTE 2Test 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
26、 be substituted for the test balls.NOTE 3With regard to the test chamber and the operating conditions, SRV models III III, IV, and IVV are identical. However, the SRV IV allowsand V allow to incline the axis of movement. Both models are fully computer controlled. In SRV IV and V models, the test des
27、cribed here is runhorizontally and without inclination. SRV I and II models can also perform this test, but they are limited with regard to maximum load and stroke. Asmodern and high performance oils may exceed an O.K.-load of 1200 N, 1200 N, seizure may not be reached. Optimol Instruments supplies
28、an upgradekit to allow for SRV I and SRV II models to be operated at 1600 N, 1600 N, if needed. SRV III test machines after 1995 reach 2000 N. SRV IV and SRVV models can be equipped with a maximum test load unit of 2500 N.5. Significance and Use5.1 This laboratory test method can be used to quickly
29、determine extreme pressure properties of lubricating oils at selectedtemperatures specified for use in applications where not only high-speed vibrational or start-stop motions are present with highHertzian point contact. This test method has found wide application in qualifying lubricating oils used
30、 in constant velocity jointsof front-wheel-drive automobiles, gear-hydraulic circuit, rear axles, gears and engine components. Users of this test method shoulddetermine whether results correlate with field performance or other applications.4 Amstutz, Hu, “Surface Texture: The Parameters,” Bulletin M
31、I-TP-003-0785, Sheffield Measurement Division, Warner and Swasey, 1985.D7421 1626. Apparatus6.1 SRV Test Machine, 5 illustrated in Figs. 1-34.6.2 Test Balls, 5 52100 steel, 6060 HRC 6 2 Rc 2 HRC hardness, 0.0250.025 m 6 0.005-m0.005 m Ra surface finish,10-mm10 mm diameter.6.3 Lower Test Disk, vacuum
32、 arc remelted (VAR) AISI 52100 steel with a inclusion rating using Method D, Type A, and aseverity level number of 0.5 according to Specification A295/A295M or Test Methods E45 or an inclusion sum value K1 10 inaccordance with DIN EN ISO 683-17 and spherodized annealed to obtain globular carbide, 60
33、60 HRC 6 2 Rc 2 HRC hardness,with the surfaces of the disk being lapped and free of lapping raw materials. The topography of the disk will be determined byfour values, 24-mm24 mm diameter by 7.85 mm 7.85 mm thick:0.5 m 20 sCoefficient of friction, f (cut-off value for one-off increase of level): 0.3
34、58.2.3 Test parameters:Frequency: 50 HzStroke: 2.00 mmTemperature: for example, 50 C or 80 C or 120 CPre-load: 50 N for 30 sTest load: running-in under 100 N for 15 min, then steps of 100 N with a duration of 2 min until the maximum test load (usually 2000 N) has been reached. Total testduration: up
35、 to 53.5 minNOTE 6Because a 30 s break-in at 50 N is used, the load increase times will occur on the half minute of even minutes.NOTE 7For optimal comparability with older SRV models I and II, the test load should be set as a ramp function with a gradient of 7.5 N s.8.2.4 Sample rates for result-rel
36、evant measurement channels:1. Base of the Receiving Block 7. Upper Specimen Holder2. Piezo Force Measurement Elements 8. Drive Rods of the Load Unit3. Supporting Surface (Head Plate) of the Receiving Block 9. Test Disk4. Lower Specimen Holder 10. Test Ball5. Position of the Electrical Resistance Hea
37、ting Resistance Thermometer Fn Normal Force (Test Load)6. Oscillation Drive Rods Ff Friction ForceFIG. 4 Test Chamber Elements of SRV Models IV and VD7421 165TABLE 1 Precision DataNOTE 1Extreme pressure pass loads of oils without outliers ( = 10 mm Ball; Stroke = 1 or 2 mm; 100 N load increment ever
38、y 2 min; = 50 Hz, data per 15.10.2006; SRV I, SRV II, SRVIII, and SRV IV models).NOTE 2The repeatability and the reproducibility were calculated using the ASTM software (ADJD6300 D2PP). Values in parentheses represent an initial, average (mean) Hertzian contactpressure using the mean test load and t
39、he initial test geometry at the beginning of the test.DIN E518345/ASTM D7421 Oil ISRVOil ISRVOil ISRVOil ISRVOil IIHLP46Oil IIHLP46Oil IIHLP46Oil IIHLP46Oil III5W-30Oil III5W-30Oil III5W-30Oil III5W-30Test-T 80C 80C 120C 120C 80C 80C 120C 120C 80C 80C 120C 120CTest-T 80 C 80 C 120 C 120 C 80 C 80 C
40、120 C 120 C 80 C 80 C 120 C 120 CStroke, mm 1 2 1 2 1 2 1 2 1 2 1 2Number of Results 30 52 30 54 30 46 30 46 30 48 30 54Degree of Freedom 17 28 16 33 17 27 19 29 17 36 16 36Higheset test load (N) mean (MPa) 890(3006)1129(3255)890(3006)1013(3139)790(2889)1521(3598)873(2987)1477(3567)1146(3270)1223(33
41、42)970(3093)1092(3218)Standard Deviation 322 186 335 172 250 217 256 217 275 203 293 150Reproducibility, R 961 540 1006 494 747 629 758 629 821 584 880 430Repeatability, r 422 185 352 247 325 292 426 334 339 410 306 250D7421166Coefficient of friction, f: #32 ms.Stroke: #2 sTest load: #2 sFrequency:
42、#2 sTemperature: #2 sAfter that, apply a load increment of 100 N every 2 minNOTE 8For SRV V models, it is recommended to do one sampling per period (that is, 20 ms) for coefficient of friction and stroke.8.12 When the 1200-N load run or maximum load of the test apparatus is completed or failure occu
43、rs, turn off the heater control,release the load to minimum setting, (typically 13 or 14 N), and remove the test ball, disk, and lubricating oil test specimen.Preparation of SRV III and IV models8.13 When using SRV III and SRV IV models, clean and install the specimens as specified under 9.1 to 9.7.
44、 Turn on the testmachine or the PC and allow to warm up for 15 min prior to running tests. The test parameters (Frequency = 50 Hz, testtemperature, stroke = 2 mm) are to be entered via the control software. The test will be run automatically. Test results (coefficientof friction, normal load, total,
45、 linear wear length, sample temperature) will be displayed and saved.8.14 Generate a dynamic test program with the following test parameters. In this dynamic test program, the maximum loadrange should be set to a maximum of 2000 N.Frequency: 50 HzTest temperature: for example, 50C, 80C, or 120CStrok
46、e: 2 mmLoad 50 N for 30 s, then apply a load increment of 100 N for 15 min.After that, apply a load increment of 100 N every 2 min.9. Procedure for All SRV Models9.1 SRV III, SRV IV, and SRV V models are fully computer-controlled and allow automated tests.9.2 Using solvent resistant gloves, clean th
47、e test ball and disk by wiping the surfaces with laboratory tissue soaked with thecleaning solvent. Repeat wiping until no dark residue appears on the tissue. Immerse the test ball and disk in a beaker of thecleaning solvent under ultrasonic vibration for 10 min. 10 min. Dry the test ball and disk w
48、ith a clean tissue to ensure no streakingoccurs on the surface.9.3 Ensure that the machine is unloaded (indicated by a load reading of 13 or 14N), and install the ball holder (upperspecimen holder).test load unit is in the release position (refer to operating manual for details).9.3 Then install the
49、 disk (place on the block). Tighten the fastening screw until resistance just begins.9.4 Place the cleaned ball, using the tweezers, in the disassembled, cleaned, and dried ball holder. Tighten the fastening screwuntil resistance just begins. Install the ball holder, and test ball in the test chamber.chamber9.5 Tighten both the ball and disk clamps until resistance to tightening just begins. Then load unit to 100 N and tighten the balland disk clamps to a torque of 2.5 Nm. R
