1、Designation: D2783 03 (Reapproved 2014)Standard Test Method forMeasurement of Extreme-Pressure Properties of LubricatingFluids (Four-Ball Method)1This standard is issued under the fixed designation D2783; the number immediately following the designation indicates the year oforiginal adoption or, in
2、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. Scope1.1 This test method covers the determination of the load-carrying properties of lubrica
3、ting fluids. The following twodeterminations are made:1.1.1 Load-wear index (formerly Mean-Hertz load).1.1.2 Weld point by means of the four-ball extreme-pressure(EP) tester.1.2 For the determination of the load-carrying properties oflubricating greases, see Test Method D2596.1.3 This standard does
4、not purport 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.1.4 The values stated in SI units are
5、to be regarded as thestandard. The values given in parentheses are for informationonly.2. Referenced Documents2.1 ASTM Standards:2D2596 Test Method for Measurement of Extreme-PressureProperties of Lubricating Grease (Four-Ball Method)2.2 ANSI Standard:B 3.12 Metal Balls33. Terminology3.1 Definitions
6、:3.1.1 compensation linea line of plot on logarithmicpaper, as shown in Fig. 1, where the coordinates are scardiameter in millimetres and applied load in kilograms-force (ornewtons), obtained under dynamic conditions.3.1.1.1 DiscussionCoordinates for the compensation lineare found in Table 1, Column
7、s 1 and 3.3.1.1.2 DiscussionSome lubricants give coordinateswhich are above the compensation line. Known examples ofsuch fluids are methyl phenyl silicone, chlorinated methylphenyl silicone, silphenylene, phenyl ether, and some mixturesof petroleum oil and chlorinated paraffins.3.1.2 compensation sc
8、ar diameterthe average diameter, inmillimetres, of the wear scar on the stationary balls caused bythe rotating ball under an applied load in the presence of alubricant, but without causing either seizure or welding.3.1.2.1 DiscussionThe wear scar obtained shall be within5 % of the values noted in Ta
9、ble 1, Column 3.3.1.3 corrected loadthe load in kilograms-force (or new-tons) for each run obtained by multiplying the applied load bythe ratio of the Hertz scar diameter to the measured scardiameter at that load.3.1.4 Hertz linea line of plot on logarithmic paper, asshown in Fig. 1, where the coord
10、inates are scar diameter inmillimetres and applied load in kilograms-force (or newtons),obtained under static conditions.3.1.5 Hertz scar diameterthe average diameter, inmillimetres, of an indentation caused by the deformation of theballs under static load (prior to test). It may be calculated fromt
11、he equationDh5 8.73 31022P!1/3(1)where:Dh= Hertz diameter of the contact area, andP = the static applied load.3.1.6 immediate seizure regionthat region of the scar-loadcurve characterized by seizure or welding at the startup or bylarge wear scars. Initial deflection of indicating pen on theoptional
12、friction-measuring device is larger than with nonsei-zure loads. See Fig. 1.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.L0.11 on Tribiological Properties of Industrial Fluids
13、andLubricates.Current edition approved Dec. 1, 2014. Published February 2015. Originallyapproved in 1969. Last previous edition approved in 2009 as D2783 03 (2009)1.This method was prepared under the joint sponsorship of the American Societyof Lubrication Engineers. Accepted by ASLE January 1969. DO
14、I: 10.1520/D2783-03R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Stan
15、dards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.7 incipient seizure or initial seizure regionthat regionat which, with an applied load, there is a momentary brea
16、k-down of the lubricating film. This breakdown is noted by asudden increase in the measured scar diameter and a momen-tary deflection of the indicating pen of the optional friction-measuring device. See Fig. 1.3.1.8 last nonseizure loadthe last load at which themeasured scar diameter is not more tha
17、n 5 % above thecompensation line at the load. See Fig. 1.3.1.9 load-wear index (or the load-carrying property of alubricant), nan index of the ability of a lubricant to minimizewear at applied loads.3.1.9.1 DiscussionUnder the conditions of this test, spe-cific loadings in kilograms-force (or Newton
18、s) having intervalsof approximately 0.1 logarithmic units, are applied to the threestationary balls for ten runs prior to welding. The load-wearindex is the average of the sum of the corrected loadsdetermined for the ten applied loads immediately preceding theweld point.3.1.10 weld pointunder the co
19、nditions of this test, thelowest applied load in kilograms at which the rotating ballwelds to the three stationary balls, indicating the extreme-pressure level of the lubricants-force (or newtons) has beenexceeded.3.1.10.1 DiscussionSome lubricants do not allow truewelding, and extreme scoring of th
20、e three stationary ballsresults. In such cases, the applied load which produces amaximum scar diameter of 4 mm is reported as the weld point.4. Summary of Test Method4.1 The tester is operated with one steel ball under loadrotating against three steel balls held stationary in the form ofa cradle. Te
21、st lubricant covers the lower three balls. Therotating speed is 1760 6 40 rpm. The machine and testlubricant are brought to 18 to 35C (65 to 95F) and then aseries of tests of 10-s duration are made at increasing loadsuntil welding occurs. Ten tests are made below the weldingpoint. If ten loads have
22、not been run when welding occurs andthe scars at loads below seizure are within 5 % of thecompensation line (AB Fig. 1) no further runs are necessary.The total can be brought to ten by assuming that loads belowthe last nonseizure load will produce wear scars equal to the“compensation scar diameter.”
23、 Values of these “assumed” scarsare given in Table 1. For clarification of “last nonseizure load”and “weld point” see Fig. 1.45. Significance and Use5.1 This test method, used for specification purposes, dif-ferentiates between lubricating fluids having low, medium, andhigh level of extreme-pressure
24、 properties. The user of thismethod should determine to his own satisfaction whetherresults of this test procedure correlate with field performance orother bench test machines.6. Apparatus6.1 Four-Ball Extreme-Pressure Tester,5illustrated in Figs.2 and 3.NOTE 1It is important to distinguish between
25、the four-ball EP testerand the four-ball wear tester. The four-ball EP tester is designed for testingunder more severe conditions and lacks the sensitivity necessary for thefour-ball wear test.6.2 Microscope, equipped with a calibrated measuring scaleand readable to an accuracy of 0.01 mm.6.3 Timer,
26、 graduated in tenths of a second.NOTE 2Optional equipment with four-ball apparatus consists of afriction-measuring device electrically driven and conveniently graduatedin 10-s markings.4Further details applicable to this method may be found in: Sayles, F. S., et al.,“The Four-Ball E. P. Tester, An A
27、STM Method of Test,” National LubricatingGrease Institute, NLGIA, Vol 32, No. 5, August 1968, pp. 162167.5Satisfactory sources of supply for this instrument are Falex Corp., 1020AirparkDr., Sugar Grove, IL 605549585 and Stanhope-Seta Ltd., Park Close, Egham,Englefield Green, Surrey, England TW20 OXD
28、.ABECompensation line.BPoint of last nonseizure load.BCRegion of incipient seizure.CDRegion of immediate seizure.DWeld point.FIG. 1 Schematic Plot of Scar Diameter Versus Applied LoadTABLE 1 Suggested Form for Recording Test ResultsColumn 1AppliedLoad, kgA(L)Column 2Average ScarDiameter,mm (X)Column
29、 3CompensationScar Diameter,mmColumn4LDhFactorColumn 5CorrectedLoad,kgA(LDh/X)6 0.958 1.4010 0.21 1.8813 0.23 2.6716 0.25 3.5220 0.27 4.7424 0.28 6.0532 0.31 8.8740 0.33 11.9650 0.36 16.1063 0.39 21.8680 0.42 30.08100 0.46 40.5126 0.50 55.2160 0.54 75.8200 0.59 102.2250 137.5315 187.1400 258500 3476
30、20 462800 649ATo convert from kilograms-force to newtons, multiply by 9.806.D2783 03 (2014)27. Materials7.1 Cleaning Solvent, safe, non-film forming, nonchlori-nated. (Warning Flammable. Harmful if inhaled. See A1.1.)NOTE 3Certain petroleum distillates, formerly used as solvents, havebeen eliminated
31、 due to possible toxic effects. Each user should select asolvent that can meet applicable safety requirements and thoroughly cleanmachine parts. Reagent Grade Stoddard solvent is an example of a solventthat has been found suitable.7.2 Rinse Solvent, same as in 7.1, but with higher volatility.ASTM n-
32、Heptane is an example of one such rinse solvent thathas been found suitable. (WarningFlammable. Harmful ifinhaled. See A1.2.)FIG. 2 Sectional View of Four-Ball TesterFIG. 3 Four-Ball EP Test MachineD2783 03 (2014)37.3 Test Balls6Test balls shall be chrome alloy steel, madefrom AISI standard steel No
33、. E-52100, with diameter of 12.7mm (0.5 in.), Grade 25 EP (Extra Polish). Such balls aredescribed in B3.12, for Metal Balls. The Extra-Polish finish isnot described in that specification. The Rockwell C hardnessshall be 64 to 66, a closer limit than is found in the ANSIrequirement.8. Preparation of
34、Apparatus8.1 Thoroughly clean four new test balls, test-lubricant cup,and chuck assemblies by first washing with cleaning solvent(see 7.1) and then rinse solvent (see 7.2).NOTE 4Do not use solvents such as carbon tetrachloride or othersolvents that may inherently possess load-carrying properties whi
35、ch mayaffect the results.8.2 Lower the crosshead by raising the lever arm. Lock thelever arm in the raised position by means of a lockingarrangement for that purpose.9. Procedure9.1 Place the three test balls in the test-lubricant cup. Placethe lock ring over the test balls and screw down the nutsec
36、urely (Note 5). Pour the lubricating fluid to be tested overthe three test balls until they are covered.NOTE 5Subsequent independent investigations reported in 1971 byseveral laboratories indicate that optimum test repeatability is obtainedwhen the force on the lock-down nut is maintained within the
37、 range 68 67 m (50 6 5 ftlb), applied, and measured by means of a torque wrench.Significantly lower weld points were obtained when the force applied wasapproximately 136 Nm (100 ftlb).9.2 Bring the lubricant and cup to 18 to 35C (65 to 95F).9.3 Press one ball into the ball chuck (Note 6) and mount t
38、hechuck into the chuck-holder.NOTE 6Examine the chuck and top ball after each run. If the ballshows signs of movement in the chuck, even though welding of thefour-balls did not occur, the chuck should be replaced. When weldingoccurs slippage between ball and chuck nearly always occurs. If the chuckh
39、as metal from the top ball adhering to it, the metal must be removed orthe chuck replaced.9.4 Install the test-lubricant cup assembly on the test appa-ratus in contact with the fourth ball. Place the spacer betweencup and thrust bearing.9.5 Place the weight tray and sufficient weights on thehorizont
40、al arm in the correct notch for a base test load of 784 N(80 kg). Release the lever arm and gently apply (Note 7) thetest load to the balls, making certain the cup assembly andspacer are centered. If the optional friction-measuring device isused, connect the calibrated arm on the test-lubricant cup
41、to theindicator spring by means of the clip and wire.NOTE 7Shock-loading should be avoided as it may deform the ballspermanently.9.6 Start the motor and run for 10 6 0.2 s.NOTE 8The time for the apparatus to “coast” to a stop is notconsidered.9.7 Remove the test-lubricant cup assembly; remove thechu
42、ck and discard the ball.9.8 Measure the scar diameter of test balls as follows:9.8.1 Option ARemove the test balls. Clean the balls withcleaning solvent (see 7.1) and then rinse solvent (see 7.2).Wipe dry with a soft cloth. Place the individual balls on asuitable holder and by means of a microscope,
43、 measure to thenearest 0.01 mm the scar diameters both parallel (horizontal)and normal (vertical) to the striations in the scar surface of oneof the three test balls (Note 9).9.8.2 Option BLeave the balls clamped in the cup. Pourout the lubricating fluid. Wash the ball surfaces with cleaningsolvent
44、(see 7.1) and then the rinse solvent (see 7.2). Using amicroscope, measure to the nearest 0.01 mm the scar diametersboth parallel (horizontal) and normal (vertical) to the striationsin the scar surface of one of the three test balls (Note 9).9.8.3 Measurements by microscope of the scar diameters ona
45、ll three balls, rather than one ball as outlined in Options A orB, may be made if the operator so desires.NOTE 9It is recommended that prior to selection of OptionAor B, theoperator examines visually the test balls to ascertain no gross discrepancyin the wear scars formed on the test balls; if discr
46、epancy is noted, thenwear scar measurements on all three test balls must be made.9.9 Record (Table 1, Column 2) for the 784 N (80-kg) loadthe average scar diameter by any one of the three techniquesdescribed in 9.8. Compare this average scar diameter with thecompensation scar diameter (Table 1, Colu
47、mn 3).9.10 Make additional runs at consecutively higher test loads(Table 1, Column 1), recording the measured scar diameter(s)(Note 10) and discarding test balls, until welding occurs (Note11). Make a check run at this point. If welding does not occuron the check run, repeat the test at the next hig
48、her load untilwelding is verified.NOTE 10Measuring the scar diameter(s) of test balls in the incipientand immediate seizure region is sometimes difficult due to the flow ofmetal obliterating the full contact area formed by the rotating ball. In suchcases the metal flow can generally be removed or pe
49、eled off with a suitableinstrument. See Figs. 4 and 5. If the scar periphery is obscure or not welldefined an estimate of the scar diameter is made. See Figs. 6 and 7.NOTE 11Shut off the motor immediately to prevent damage to thetester. Excessive seizure between the ball and ball chuck may result ifcaution is not observed. Welding may be detected by any or all of thefollowing: (1) If friction-measuring device is used, a sharp transversemovement of the indicating pen, (2) increased noise level of motor, (3)smoking from test-oil cup,
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