1、Designation: D2509 141Standard Test Method forMeasurement of Load-Carrying Capacity of LubricatingGrease (Timken Method)1This standard is issued under the fixed designation D2509; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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.1NOTEThe IP designation was removed and footnote 1 was revised editorially in March 2017.1. Scope*1.1 This test method co
3、vers the determination of the load-carrying capacity of lubricating greases by means of theTimken Extreme Pressure Tester.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 purport to address all of
4、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. For specificwarning statements, see 7.1, 7.2, and 9.4.2. Referenced
5、 Documents2.1 ASTM Adjuncts:Glossy Prints of Test Blocks Showing Various Types ofScar23. Terminology3.1 Definitions:3.1.1 load-carrying capacity, of a lubricating grease, nthemaximum load or pressure that can be sustained by a lubricat-ing grease without failure of the sliding contact surfaces asevi
6、denced by seizure or welding.3.1.1.1 DiscussionThe values of load carrying capacity ofa lubricating grease vary according to test method.3.1.2 scoring, in tribology, na severe form of wear char-acterized by the formation of extensive grooves and scratchesin the direction of sliding.3.1.2.1 Discussio
7、nWhen the lubricant film is substantiallymaintained, a smooth scar is obtained on the test block, butwhen there is a breakdown of the lubricant film, scoring orsurface failure of the test block takes place as shown in Fig. 1.2In its simplest and recognized form, scoring is characterized bya wide sca
8、r on the test block and by the transfer of metal fromthe test block to the contacting surface of the test cup.The formof surface failure more usually encountered, however, consistsof a comparatively smooth scar, which shows local damagethat usually extends beyond the width of the scar. Scratches ors
9、triations that occur in an otherwise smooth scar and that do notextend beyond the width of the scar are not considered scoringin this test method. The term scuffing is sometimes used as asynonym for scoring.3.1.3 seizure or welding, nlocalized fusion of rubbingmetal, usually indicated by streaks of
10、transferred metal, in-creased friction and wear, or unusual noise and vibration.3.1.4 wear, nthe removal of metal from a rubbing surfaceby mechanical action, or by a combination of mechanical andchemical actions.3.2 Definitions of Terms Specific to This Standard:3.2.1 OK value, nthe maximum mass (we
11、ight) added tothe load lever mass (weight) pan, at which no scoring orseizure occurs.3.2.2 score value, nthe minimum mass (weight) added tothe load lever mass (weight) pan, at which scoring or seizureoccurs.4. Summary of Test Method4.1 The tester is operated with a steel test cup rotatingagainst a s
12、teel test block.The rotational speed is 800 6 5 r/min,which is equivalent to a linear speed of 123.71 6 0.77 m/min(405.88 6 2.54 ft/min). Grease samples are brought to andapplied at 24 6 6C (75 6 10F).4.2 Two determinations are made: the minimum load (scorevalue) that will rupture the lubricant film
13、 being tested betweenthe rotating cup and the stationary block and cause adhesion;and the maximum load (OK value) at which the rotating cupwill not rupture the lubricant film and cause adhesion betweenthe rotating cup and the stationary block.1This test method is under the jurisdiction of ASTM Commi
14、ttee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.G0.04 on Functional Tests - Tribology.Current edition approved Oct. 1, 2014. Published February 2015. Originallyapproved in 1966. Last previous edition approved in 2008 as D2509 03 (2008).
15、DOI:10.1520/D2509-14E01.2Available from ASTM International Headquarters. Order Adjunct No.ADJD2509. Original adjunct produced in 1972.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. U
16、nited StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barri
17、ers to Trade (TBT) Committee.15. Significance and Use5.1 The test method is used widely for specification pur-poses and is used to differentiate between greases having low,medium, or high levels of extreme pressure characteristics. Theresults may not correlate with results from service.6. Apparatus
18、and Materials6.1 Timken Extreme Pressure Tester , described in detail inAnnex A1 and illustrated in Fig. 2.6.2 Sample Feed Devices, for supplying the test specimenswith grease are described in Annex A1.6.3 Loading Mechanism, for applying and removing theload mass (weight) without shock at the unifor
19、m rate 0.91 to1.36 kg/s (2 to 3 lb/s).Adetailed description is given in AnnexA1.6.4 Test Cups,3,4of carburized steel, having a RockwellHardness C Scale Number of 58 to 62, or a Vickers HardnessNumber of 653 to 746. The cups have a width of 13.06 6 0.05mm (0.514 6 0.002 in.), a perimeter of 154.51 6
20、0.23 mm(6.083 6 0.009 in.), a diameter of 49.22 +0.025, 0.127 mm(1.938 +0.001, 0.005 in.), and a maximum radial run-out of0.013 mm (0.0005 in.). The axial surface roughness should liebetween 0.51 and 0.76 m (20 and 30 in.) C.L.A.6.5 Test Blocks4,5with test surfaces 12.32 6 0.10 mm (0.4856 0.004 in.)
21、 wide and 19.05 6 0.41 mm (0.750 6 0.016 in.)long, of carburized steel, having a Rockwell Hardness C ScaleNumber of 58 to 62, or a Vickers Hardness Number of 653 to746. Each block is supplied with four ground faces and thesurface roughness should lie between 0.51 and 0.76 m (20 and30 in.) C.L.A.6.6
22、Microscope,4,6low-power (50 to 60), having suffi-cient clearance under objective to accommodate the test block.It should be fitted with a filar micrometer so that the scar widthmay be measured with an accuracy of 60.05 mm (60.002 in.).6.7 Timer, graduated in minutes and seconds.7. Reagents7.1 Aceton
23、e, reagent grade, minimum purity. (WarningExtremely flammable. Vapors can cause flash fire.)7.2 Stoddard Solvent, also known as Mineral Spirits, reagentgrade. (WarningCombustible. Vapor harmful.)8. Preparation of Apparatus8.1 Clean the apparatus with Stoddard solvent and acetone(see 7.1 and 7.2), an
24、d blow dry. Shield the sump outlet anddisconnect the oil pump to eliminate wear on the unused pump.Replace the oil reservoir with the grease feed device.3The sole source of supply of the test cups known to the committee at this timeis Falex Corporation, 1020 Airpark Dr., Sugar Grove, IL, 60554-9585
25、under PartNo. F-25061.4If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.5The sole source of supply of the test bloc
26、ks known to the committee at this timeis Falex Corporation, 1020 Airpark Dr., Sugar Grove, IL, 60554-9585 under PartNo. F-25001.6The sole source of supply of the apparatus known to the committee at this timeis Falex Corporation, 1020 Airpark Dr., Sugar Grove, IL, 60554-9585.FIG. 1 Test Blocks Showin
27、g Various Types of ScarD2509 14128.2 Select a new test cup and block, wash with Stoddardsolvent, and dry with a clean soft cloth or paper. Immediatelybefore use rinse the test cup and block with acetone and blowthem dry. Do not use solvents such as carbon tetrachloride orothers that may inherently p
28、ossess load-carrying propertieswhich may affect the results.8.3 Assemble the tester carefully (Fig. 3), placing the testcup on the spindle and making certain that it is well seated,drawing it up firmly but avoiding possible distortion fromexcessive tightening (Note 1). Place the test block in the te
29、stblock holder and adjust the levers so that all the knife edges arein proper alignment. Exercise special care in placing the stirrupof the spring-weight platform assembly (selection of whichwill depend on the loading device) in the groove of theload-lever arm to avoid premature shock to the test bl
30、ock whenthe load is applied. To ensure the test block, test block holder,and lever arms are properly aligned and seated, coat the testblock and test cup with the grease to be tested, and rotate themachine slowly for a few revolutions either by hand or bysuitable control mechanism. If the parts are i
31、n alignment, thegrease will be wiped off the cup over its entire width.NOTE 1At this point it is recommended that a dial indicator be usedto check that the radial run-out of the cup in situ does not exceed 0.001 in.(0.025 mm) total indicator movement.9. Procedure9.1 Bring the grease to 24 6 6C (75 6
32、 10F). Fill thegrease-feeding device with grease, avoiding the inclusion of airbubbles. Apply a film of grease to the test cup and block andthoroughly grease the guide bushing with the test grease. Donot heat the grease.9.2 Apply the grease at 24 6 6C (75 6 10F) to the testblock through the grease-f
33、eed mechanism at the uniform rate of45 6 9 g/min (0.1 6 0.02 lb/min). Start the motor and run for30 s to break-in. If the equipment used is equipped withacceleration control, start the motor and gradually increase therotational speed of the spindle to achieve 800 6 5 rpm after15 s. Run for a further
34、 15 s to complete the break-in.FIG. 2 Timken TesterD2509 14139.3 After the break-in period of 30 s, start the timer andapply at 8.9 to 13.3 N/s (2 to 3 lbf/s), a load of 133.4 N (30 lbf).(A starting load of 133.4 N (30 lbf/s) is recommended. Theload lever arm, spring, and mass (weight) carrier assem
35、bly arenot considered part of the applied load.) Then allow themachine to run at 800 6 5 rpm for 10 min 6 15 s after loadapplication is initiated, unless a score is detected before thatperiod. Excessive noise and fluctuations in the spindle speedindicate scoring of the test components. Stop the mach
36、ine atonce, turn off the supply of grease lubricant, and remove theload.9.4 If, after the load has been applied, scoring is evident byvibration or noise, stop the tester at once, remove the load, andturn off the flow of lubricant. Since the excessive heatFIG. 2 Timken Tester (continued)FIG. 3 Assemb
37、ly of Tester Showing Test PiecesD2509 1414developed with deep scoring may alter the surface character-istics of the entire block, discard the test block. (WarningThe machine and test pieces may be hot at this point and careshould be exercised in their handling.)9.5 If no scoring/scuffing is detected
38、, allow the tester to runfor 10 min 6 15 s from the start of the application of the load.At the end of the 10 min 6 15 s period, reverse the loadingdevice and remove the load from the lever arm. Turn off themotor, allow the spindle to come to rest, then turn off the flowof grease. Remove the load le
39、ver and inspect the condition ofthe test block surface. The lubricant has failed at the imposedload if the wear scar indicates any scoring/scuffing or welding.Significant tapering indicates improper alignment or setup andtest run should be repeated. See Fig. 1.NOTE 2Microscopical observations should
40、 not be used to define ifscoring has occurred, but a skilled operator may use a microscope toexamine the wear scar for further information.9.6 If no score is observed, turn the test block to expose anew surface of contact and, with a new test cup, repeat the testwith a load 44.5-N (10-lbf) heavier a
41、nd in successive testsincrease it in 44.5-N (10-lbf) increments until a load thatproduces a score is reached. At this point decrease the load by22.2 N (5 lbf) for the final determination.9.7 If a score is produced at the 133.4-N (30-lbf) load,reduce the load by 26.7-N (6-lbf) decrements until no sco
42、ringis realized.At this point, increase the load by 13.3 N (3 lbf) forthe final determination.9.8 When the wear scar evidence at any load stage makesthe definition of the onset of scoring questionable, repeat thetest at the same load. If the second test produces a score, recorda score rating for thi
43、s load. Similarly, if the second testproduces no scoring, record a no score rating. If the second testagain yields a questionable result, simply withhold judgment ofthe rating at this load stage and test the grease at theimmediately next higher and lower load stages. Then assign arating to the load
44、stage in question which is identical to therating obtained at the immediately next higher load stageemployed (see Annex A2).NOTE 3Two other procedures that may be conducted with thisapparatus are described by Appendix X1 and Appendix X2.10. Calculation and Report10.1 Report the OK and score values i
45、n terms of the masses(weights) placed on the mass (weight) pan hanging from theend of the load-lever arm; do not include the mass (weight) ofthe pan assembly. Report the values in multiples of 2.27 kg (5lb) above 13.71 kg (30 lb) and in multiples of 1.36 kg (3 lb)below 30 lb.10.2 When desired, the c
46、ontact (unit) pressure which existsbetween the cup and block at the conclusion of the test may becalculated.7After the OK value has been determined, removethe test block and wash with Stoddard solvent, rinse withacetone, and blow dry. By means of a filar micrometermicroscope, measure the width of th
47、e scars on those blockswhich successfully carried this load. Make all measurements to0.05 mm (0.002 in.) Calculate the contact pressure, C,asfollows:C, psi 5 LX1G!#/YZ or 20X1G!#/Z (1)C, MPa 5 9.81 LX10.454G!#/YZ (2)where:L = 10 = mechanical advantage of load-lever arm,G = load-lever constant (value
48、 is stamped on lever arm ofeach tester),X = mass (weight) placed on the weight pan, lbX = mass (weight) placed on the weight pan, kg,Y = length of test scar (1/2 in.),Y = length of test scar (12.7 mm),Z = average width of test scar, in., andZ = average width of test scar, mm.11. Precision and Bias11
49、.1 The precision of this test is not known to have beenobtained in accordance with currently accepted guidelines (forexample, Research Report RR:D02-1007).11.2 The following criteria should be used for judging theacceptability of OK load results (95 % confidence):11.2.1 RepeatabilityDuplicate results by the same opera-tor should be considered suspect if they differ by more than23 % of their mean. Table X3.1, based on this level ofrepeatability, and the use of the load increments specified in themethod, may be used to quickly check the
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1