1、Designation: D 2783 03 (Reapproved 2009)Standard Test Method forMeasurement of Extreme-Pressure Properties of LubricatingFluids (Four-Ball Method)1This standard is issued under the fixed designation D 2783; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n 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 lubri
3、cating 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 D 2596.1.3 This standard do
4、es 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 a
5、re to be regarded as thestandard. The values given in parentheses are for informationonly.2. Referenced Documents2.1 ASTM Standards:2D 2596 Test Method for Measurement of Extreme-PressureProperties of Lubricating Grease (Four-Ball Method)2.2 ANSI Standard:B 3.12 Metal Balls33. Terminology3.1 Definit
6、ions: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, Co
7、lumns 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 compensatio
8、n scar 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 i
9、n Table 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 c
10、oordinates are scar diameter inmillimetres and applied load in kilograms-force (or newtons),obtained under static conditions.3.1.5 Hertz scar diameterthe average diameter, in milli-metres, of an indentation caused by the deformation of the ballsunder static load (prior to test). It may be calculated
11、 from theequation1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.L0.11 on Tribiological Properties of Industrial Fluids and Lubricates.Current edition approved April 15, 2009. Published July 200
12、9. Originallyapproved in 1969. Last previous edition approved in 2003 as D 2783 03.This method was prepared under the joint sponsorship of the American Societyof Lubrication Engineers. Accepted by ASLE January 1969.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
13、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 Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.ABECompensation line.BPoint of last non
14、seizure load.BCRegion of incipient seizure.CDRegion of immediate seizure.DWeld point.FIG. 1 Schematic Plot of Scar Diameter Versus Applied Load1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Dh5 8.73 3 1022P!1/3(1)where:Dh= Hertz dia
15、meter 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 friction-measuring device is larger than with nonsei
16、-zure loads. See Fig. 1.3.1.7 incipient seizure or initial seizure regionthat regionat which, with an applied load, there is a momentary break-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
17、the optional friction-measuring device. See Fig. 1.3.1.8 last nonseizure loadthe last load at which themeasured scar diameter is not more than 5 % above thecompensation line at the load. See Fig. 1.3.1.9 load-wear index (or the load-carrying property of alubricant)an index of the ability of a lubric
18、ant to minimizewear at applied loads. Under the conditions of this test, specificloadings in kilograms-force (or newtons) having intervals ofapproximately 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 th
19、e corrected loadsdetermined for the ten applied loads immediately preceding theweld pair.3.1.10 weld pointunder the conditions 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-forc
20、e (or newtons) has beenexceeded.3.1.10.1 DiscussionSome lubricants do not allow truewelding, and extreme scoring of the 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 i
21、s operated with one steel ball under loadrotating against three steel balls held stationary in the form ofa cradle. Test 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 du
22、ration are made at increasing loadsuntil welding occurs. Ten tests are made below the weldingpoint. If ten loads have 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
23、by assuming that loads belowthe last nonseizure load will produce wear scars equal to the“compensation scar diameter.” 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 sp
24、ecification purposes, dif-ferentiates between lubricating fluids having low, medium, andhigh level of extreme-pressure 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. App
25、aratus6.1 Four-Ball Extreme-Pressure Tester,5illustrated in Figs.2 and 3.NOTE 1It is important to distinguish between 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
26、 wear test.6.2 Microscope, equipped with a calibrated measuring scaleand readable to an accuracy of 0.01 mm.6.3 Timer, 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 markin
27、gs.7. Materials7.1 Cleaning Solvent, safe, non-film forming, nonchlori-nated. (WarningFlammable. Harmful if inhaled. See A1.1.)NOTE 3Certain petroleum distillates, formerly used as solvents, havebeen eliminated due to possible toxic effects. Each user should select asolvent that can meet applicable
28、safety requirements and thoroughly cleanmachine parts. Reagent Grade Stoddard solvent is an example of a solventthat has been found suitable.4Further details applicable to this method may be found in: Sayles, F. S., et al.,“The Four-Ball E. P. Tester, An ASTM Method of Test,” National LubricatingGre
29、ase 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.TABLE 1 Suggested Form for Recording Test R
30、esultsColumn 1AppliedLoad, kgA(L)Column 2Average ScarDiameter,mm (X)Column 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.
31、5126 0.50 55.2160 0.54 75.8200 0.59 102.2250 137.5315 187.1400 258500 347620 462800 649ATo convert from kilograms-force to newtons, multiply by 9.806.D 2783 03 (2009)27.2 Rinse Solvent, same as in 7.1, but with higher volatility.ASTM n-Heptane is an example of one such rinse solvent thathas been fou
32、nd suitable. (WarningFlammable. Harmful ifinhaled. See A1.2.)FIG. 2 Sectional View of Four-Ball TesterFIG. 3 Four-Ball EP Test MachineD 2783 03 (2009)37.3 Test Balls6Test balls shall be chrome alloy steel, madefrom AISI standard steel No. E-52100, with diameter of 12.7mm (0.5 in.), Grade 25 EP (Extr
33、a Polish). Such balls aredescribed in ANSI Specifications B 3.12, for Metal Balls. TheExtra-Polish finish is not described in that specification. TheRockwell C hardness shall be 64 to 66, a closer limit than isfound in the ANSI requirement.8. Preparation of Apparatus8.1 Thoroughly clean four new tes
34、t 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 which mayaffect the results.8.2 Lower the cro
35、sshead 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 nutsecurely (Note 5). Pour the lubricating fluid
36、 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 range 68 67 h m (50 6 5 ftlb), applied, a
37、nd 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 thechuck into the chuck-holder.NOTE 6Exam
38、ine 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 chuckhas metal from the top ball adhering to i
39、t, 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 thehorizontal arm in the correct notch for a base t
40、est 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 to theindicator spring by means of the c
41、lip 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 thechuck and discard the ball.9.8 Measure the
42、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, measure to thenearest 0.01 mm the scar
43、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 (see 7.1) and then the rinse solvent (se
44、e 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 onall three balls, rather than one ball as
45、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 discrepancy is noted, thenwear scar measureme
46、nts 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, Column 3).9.10 Make additional runs at conse
47、cutively 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 higher load untilwelding is verified.NOTE 1
48、0Measuring 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 peeled off with a suitableinstrument. See
49、Figs. 4 and 5. If the scar periphery is obscure or not well6Steel balls meeting this description were used in developing the precision of thetest. They are available from the manufacturer of the test machine. All balls used inone test should be taken from one carton (of 500 balls) as received from the supplier. FIG. 4 Typical Test Ball ScarsBefore RemovalD 2783 03 (2009)4defined 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
