1、Designation: D 2783 03An American National StandardStandard 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 ado
2、ption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the load-carrying propert
3、ies of lubricating 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
4、 standard does 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 i
5、n SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.2. Referenced Documents2.1 ASTM Standards:D 2596 Test Method for Measurement of Extreme-PressureProperties of Lubricating Grease (Four-Ball Method)22.2 ANSI Standard:B 3.12 Metal Balls33. Terminolog
6、y3.1 Definitions: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
7、 Table 1, Columns 1 and 3.3.1.1.2 DiscussionSome lubricants give coordinateswhich are above the compensation line. Known examples of1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.L0 on Industri
8、al Lubricants.Current edition approved Aug. 10, 2003. Published September 2003. Originallyapproved in 1969. Last previous edition approved in 1998 as D 278388 (1998).This method was prepared under the joint sponsorship of the American Societyof Lubrication Engineers. Accepted by ASLE January 1969.2A
9、nnual Book of ASTM Standards, Vol 05.01.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.ABECompensation line.BPoint of last nonseizure load.BCRegion of incipient seizure.CDRegion of immediate seizure.DWeld point.FIG. 1 Schematic Plot of Scar
10、 Diameter Versus Applied LoadTABLE 1 Suggested Form for Recording Test ResultsColumn 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
11、.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 347620 462800 649ATo convert from kilograms-force to newtons, multiply by 9.806.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consho
12、hocken, PA 19428-2959, United States.such fluids are methyl phenyl silicone, chlorinated methylphenyl silicone, silphenylene, phenyl ether, and some mixturesof petroleum oil and chlorinated paraffins.3.1.2 compensation scar diameterthe average diameter, inmillimetres, of the wear scar on the station
13、ary 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 Table 1, Column 3.3.1.3 corrected loadthe load in kilograms-force (or new-tons) f
14、or 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 coordinates are scar diameter inmillimetres and applied load in kilograms-force (or
15、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 from theequationDh5 8.73 3 1022P!1/3(1)where:Dh= Hertz diameter of the contact are
16、a, 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-zure loads. See Fig. 1.
17、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 the optional friction-me
18、asuring 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 lubricant to minimizewear at a
19、pplied 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 the corrected loadsdetermi
20、ned 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-force (or newtons) has beene
21、xceeded.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 is operated with one stee
22、l 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 duration are made at incre
23、asing 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 by assuming that loads b
24、elowthe 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 specification purposes, di
25、f-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. Apparatus6.1 Four-Ball Extr
26、eme-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 wear test.6.2 Microscop
27、e, 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 markings.7. Materials7.1 Clean
28、ing 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 safety requirements and
29、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-Heptane is an example of one such rinse solvent thathas been found suitable. (WarningFlammable. Harmful ifinhaled.
30、 See A1.2.)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 LubricatingGrease Institute, NLGIA, Vol 32, No. 5, August 1968, pp. 162167.5Satisfactory sources of supply for this instrument are Falex Corp.,
31、1020AirparkDr., Sugar Grove, IL 605549585 and Stanhope-Seta Ltd., Park Close, Egham,Englefield Green, Surrey, England TW20 OXD.D2783032FIG. 2 Sectional View of Four-Ball TesterFIG. 3 Four-Ball EP Test MachineD27830337.3 Test Balls6Test balls shall be chrome alloy steel, madefrom AISI standard steel
32、No. E-52100, with diameter of 12.7mm (0.5 in.), Grade 25 EP (Extra 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 require
33、ment.8. Preparation of 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-
34、carrying properties which 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 an
35、d screw down the nutsecurely (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 i
36、s maintained within the range 68 67 h 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 c
37、huck (Note 6) and mount thechuck 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 alw
38、ays occurs. If the chuckhas 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 sufficie
39、nt weights on thehorizontal 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 o
40、n the test-lubricant cup 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 cu
41、p assembly; remove thechuck 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
42、by means of a microscope, 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 surfa
43、ces with cleaningsolvent (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
44、of the scar diameters onall 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
45、 the test balls; if discrepancy 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 sca
46、r diameter (Table 1, Column 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
47、 the test at the next higher 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 g
48、enerally be removed or peeled off with a suitableinstrument. See 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
49、should be taken from one carton (of 500 balls) as received from the supplier. FIG. 4 Typical Test Ball ScarsBefore RemovalD2783034defined 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)smo
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