1、Designation:D250914Designation:326/83(88)Standard 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
2、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 the determination of the load-carrying capacity of lubricating greases by
3、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 thesafety concerns,if any,associated with its use.It is theresponsibility of the
4、 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 Documents2.1 ASTM Adjuncts:Glossy Prints of Test Blocks Showing Various Types ofScar23.
5、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 asevidenced by seizure or welding.3.1.1.1 DiscussionThe values of load carrying capacity ofa lub
6、ricating 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 DiscussionWhen the lubricant film is substantiallymaintained,a smooth scar is obtained on the test blo
7、ck,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 scar on the test block and by the transfer of metal fromthe test block to the contacting surface of t
8、he 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 orstriations that occur in an otherwise smooth scar and that do notextend beyond the width of the scar ar
9、e 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 transferred metal,in-creased friction and wear,or unusual noise and vibration.3.1.4 wear,nthe removal of
10、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(weight)added tothe load lever mass(weight)pan,at which no scoring orseizure occurs.3.2.2 score value,nthe minimum
11、 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 steel 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
12、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 being tested betweenthe rotating cup and the stationary block and cause adhesion;and the maximum load(OK value)at which the ro
13、tating 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 Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.G0.04 on Functional
14、 Tests-Tribology.Current edition approved Oct.1,2014.Published February 2015.Originallyapproved in 1966.Last previous edition approved in 2008 as D2509 03(2008).This test method was adopted as an ASTM-IP Standard.DOI:10.1520/D2509-14.2Available from ASTM International Headquarters.Order Adjunct No.A
15、DJD2509.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.United States1 5.Significance and Use5.1 The test method is used widely for specification pur-pose
16、s 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 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 uniform rate 0.91 to1.36 kg/s(