1、Designation: D6185 10Standard Practice forEvaluating Compatibility of Binary Mixtures of LubricatingGreases1This standard is issued under the fixed designation D6185; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 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 practice covers a protocol for evaluating thecompatibility of one or three binary mixtures of lubricatinggreases by c
3、omparing their properties or performance relativeto those of the neat greases comprising the mixture.1.2 Three properties are evaluated in a primary testingprotocol using standard test methods: (1) dropping point byTest Method D566 (or Test Method D2265); (2) shear stabilityby Test Methods D217, 100
4、 000stroke worked penetration;and (3) storage stability at elevated-temperature by change in60-stroke penetration (Test Method D217). For compatiblemixtures (those passing all primary testing), a secondary(nonmandatory) testing scheme is suggested when circum-stances indicate the need for additional
5、 testing.1.3 Sequential or concurrent testing is continued until thefirst failure. If any mixture fails any of the primary tests, thegreases are incompatible. If all mixtures pass the three primarytests, the greases are considered compatible.1.4 This practice applies only to lubricating greases havi
6、ngcharacteristics suitable for evaluation by the suggested testmethods. If the scope of a specific test method limits testing tothose greases within a specified range of properties, greasesoutside that range cannot be tested for compatibility by that testmethod. An exception to this would be when th
7、e testedproperty of the neat, constituent greases is within the specifiedrange, but the tested property of a mixture is outside the rangebecause of incompatibility.1.5 This practice does not purport to cover all test methodsthat could be employed.1.6 The values stated in SI units are to be regarded
8、asstandard. No other units of measurement are included in thisstandard.1.7 This standard does not purport to address all the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andpractices and determine the applicabil
9、ity of regulatory limita-tions prior to use. For specific safety information, see 7.2.3.2. Referenced Documents2.1 ASTM Standards:2D217 Test Methods for Cone Penetration of LubricatingGreaseD566 Test Method for Dropping Point of LubricatingGreaseD972 Test Method for Evaporation Loss of LubricatingGr
10、eases and OilsD1092 Test Method for Measuring Apparent Viscosity ofLubricating GreasesD1263 Test Method for Leakage Tendencies of AutomotiveWheel Bearing Greases3D1264 Test Method for Determining the Water WashoutCharacteristics of Lubricating GreasesD1403 Test Methods for Cone Penetration of Lubric
11、atingGrease Using One-Quarter and One-Half Scale ConeEquipmentD1478 Test Method for Low-Temperature Torque of BallBearing GreaseD1742 Test Method for Oil Separation from LubricatingGrease During StorageD1743 Test Method for Determining Corrosion PreventiveProperties of Lubricating GreasesD1831 Test
12、Method for Roll Stability of Lubricating GreaseD2265 Test Method for Dropping Point of LubricatingGrease Over Wide Temperature RangeD2266 Test Method for Wear Preventive Characteristics ofLubricating Grease (Four-Ball Method)D2509 Test Method for Measurement of Load-CarryingCapacity of Lubricating G
13、rease (Timken Method)D2595 Test Method for Evaporation Loss of LubricatingGreases Over Wide-Temperature RangeD2596 Test Method for Measurement of Extreme-PressureProperties of Lubricating Grease (Four-Ball Method)D3336 Test Method for Life of Lubricating Greases in BallBearings at Elevated Temperatu
14、res1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.G0.01on Chemical and General Laboratory Tests.Current edition approved July 1, 2010. Published July 2010. Originally approvedin 1997. Last previo
15、us edition approved in 2008 as D618597(2008). DOI:10.1520/D6185-10.2For 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 we
16、bsite.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D3337 Test Method for Determining Life and Torque ofLubricating Greases in Small Bal
17、l Bearings3D3527 Test Method for Life Performance of AutomotiveWheel Bearing GreaseD4049 Test Method for Determining the Resistance ofLubricating Grease to Water SprayD4170 Test Method for Fretting Wear Protection by Lubri-cating GreasesD4175 Terminology Relating to Petroleum, PetroleumProducts, and
18、 LubricantsD4290 Test Method for Determining the Leakage Tenden-cies of Automotive Wheel Bearing Grease Under Acceler-ated ConditionsD4425 Test Method for Oil Separation from LubricatingGrease by Centrifuging (Koppers Method)D4693 Test Method for Low-Temperature Torque ofGrease-Lubricated Wheel Bear
19、ingsD4950 Classification and Specification for Automotive Ser-vice GreasesD5706 Test Method for Determining Extreme PressureProperties of Lubricating Greases Using a High-Frequency, Linear-Oscillation (SRV) Test MachineD5707 Test Method for Measuring Friction and Wear Prop-erties of Lubricating Grea
20、se Using a High-Frequency,Linear-Oscillation (SRV) Test Machine2.2 Federal Standard:Federal Test Method 3467.1 (Standard 791C), Storage Sta-bility of Lubricating Grease43. Terminology3.1 Definitions:3.1.1 bleed (bleeding), nof lubricating greases, the sepa-ration of a liquid lubricant from a lubrica
21、ting grease for anycause.3.1.2 lubricant, nany material interposed between twosurfaces that reduces the friction or wear between them.D41753.1.3 lubricating grease, na semifluid to solid product ofa dispersion of a thickener in a liquid lubricant.3.1.3.1 DiscussionThe dispersion of the thickener for
22、ms atwo-phase system and immobilizes the liquid lubricant bysurface tension and other physical forces. Other ingredientsimparting special properties are often included. D2173.1.4 spatulate, vto mix or blend by spreading and foldingwith a flat thin, usually metal, tool.3.1.5 syneresis, nof lubricatin
23、g greases, the separation ofliquid lubricant from a lubricating grease due to shrinkage orrearrangement of the structure.3.1.5.1 DiscussionSyneresis is a form of bleeding causedby physical or chemical changes of the thickness. Separation offree oil or the formation of cracks that occur in lubricatin
24、ggreases during storage in containers is most often due tosyneresis.3.1.6 thickener, nin a lubricating grease, a substancecomposed of finely divided particles dispersed in a liquidlubricant to form the products structure.3.1.6.1 DiscussionThe thickener can be fibers (such asvarious metallic soaps) o
25、r plates or spheres (such as certainnon-stop thickeners) which are insoluble or, at most, only veryslightly soluble in the liquid lubricant. The general require-ments are that the solid particles be extremely small, uniformlydispersed, and capable of forming a relatively stable, gel-likestructure wi
26、th the liquid lubricant. D2173.2 Definitions of Terms Specific to This Standard:3.2.1 compatibility, n of lubricating greases, the charac-teristic of lubricating greases to be mixed together withoutsignificant degradation of properties or performance.3.2.1.1 DiscussionWhen a mixture of two greases h
27、asproperties or performance significantly inferior to both of theneat, constituent greases, then the two greases are incompat-ible. If the properties are inferior to those of one neat grease butnot inferior to those of the other, then such is not necessarilyconsidered an indication of incompatibilit
28、y. To be consideredsignificantly inferior, the property of the mixture would beworse than the poorer of the two neat greases by an amountexceeding the repeatability of the test method used to evaluatethe property (see pass and fail). Incompatibility most often ismanifested by a degradation in physic
29、al properties rather thanin chemical properties, although, occurrence of the latter is notunknown.3.2.2 borderline compatibility, nof lubricating greases,the characteristic of lubricating greases to be mixed togetherwith only slight degradation of properties or performance.3.2.2.1 DiscussionSlight d
30、egradation means that theproperties or performance of the mixture is poorer than those ofthe two neat greases but by an amount less than the repeatabil-ity of the test method used to evaluate the property. (Seeborderline pass.)3.2.3 primary compatibility tests, nof lubricating greases,those test met
31、hods employed first to evaluate compatibility.3.2.3.1 DiscussionThe test methods considered the mostsignificant in the evaluation of grease compatibility, insofar asthey provide the most information with the least expenditure oftesting resources, include tests for dropping point, consistency(usually
32、 softening) after shearing conditions, and consistencychange after storage at elevated temperatures.3.2.4 secondary compatibility tests, nof lubricatinggreases, those test methods used to evaluate compatibilitywhen the primary compatibility tests are insufficient or incon-clusive.3.2.4.1 DiscussionS
33、uch tests are driven by the criticalfeatures of a given application. For example, if the applicationsubjects the grease to water contamination, water washout orwater spray-off tests and, perhaps, corrosion tests would beused for additional evaluation. Secondary compatibility testsare suggested, but
34、not required, by this practice.3.2.5 pass, nin compatibility testing of grease mixtures, atest result that is equal to or better than that of the poorer of thetwo constituent greases.3.2.6 borderline pass, n in compatibility testing of greasemixtures, a test result that is inferior to that of the po
35、orer of thetwo constituent greases by an amount not exceeding therepeatability of the test method used for the evaluation.4Available from Standardization Documents Order Desk, Bldg. 4, Section D,700 Robbins Ave., Philadelphia, PA 191115094, Attn: NPODS.D6185 1023.2.6.1 DiscussionBorderline pass, bor
36、derline fail, bor-derline compatible, and borderline incompatible are synony-mous terms.3.2.7 fail, nin compatibility testing of grease mixtures, atest result that is inferior to that of the poorer of the twoconstituent greases by an amount exceeding the repeatability ofthe test method used for the
37、evaluation.3.2.8 50:50 mixture, na uniform blend of 50 mass % ofeach of two component greases.3.2.9 10:90 mixture, na uniform blend of 10 mass % ofone grease with 90 mass % of a second grease.3.2.10 90:10 mixture, na uniform blend of 90 mass % ofone grease with 10 mass % of a second grease.4. Summar
38、y of Practice4.1 Option 1A 50:50 mixture of two greases to beevaluated for compatibility is prepared by spatulating. Thismixture and the two neat, constituent greases are tested usingthe primary compatibility tests (dropping point, 100 000-strokeworked penetration, and change in 60-stroke penetratio
39、n due tohigh-temperature storage). Depending on the performance ofthe mixture, relative to those of the constituent greases, 10:90and 90:10 mixtures may need to be tested in addition. Alter-natively, Option 2 can be used. Instead of testing mixtures insequential order, 10:90 and 90:10 mixtures are t
40、ested at thesame time the 50:50 mixture is evaluated. If all mixtures passthe primary compatibility tests, or if the application requiresthe evaluation of specific properties, secondary compatibilitytests can be employed for further evaluation. Such tests can berun concurrently, if desired.5. Signif
41、icance and Use5.1 The compatibility of greases can be important for usersof grease-lubricated equipment. It is well known that themixing of two greases can produce a substance markedlyinferior to either of its constituent materials. One or more of thefollowing can occur. A mixture of incompatible gr
42、eases mostoften softens, sometimes excessively. Occasionally, it canharden. In extreme cases, the thickener and liquid lubricant willcompletely separate. Bleeding can be so severe that the mixedgrease will run out of an operating bearing. Excessive syneresiscan occur, forming pools of liquid lubrica
43、nt separated from thegrease. Dropping points can be reduced to the extent thatgrease or separated oil runs out of bearings at elevatedoperating temperatures. Such events can lead to catastrophiclubrication failures.5.1.1 Because of such occurrences, equipment manufactur-ers recommend completely clea
44、ning the grease from equipmentbefore installing a different grease. Service recommendationsfor grease-lubricated equipment frequently specify the cave-atdo not mix greases under any circumstances. Despite thisadmonition, grease mixing will occur and, at times, cannot beavoided. In such instances, it
45、 would be useful to know whetherthe mixing of two greases could lead to inadequate lubricationwith disastrous consequences. Equipment users most often donot have the resources to evaluate grease compatibility andmust rely on their suppliers. Mixing of greases is a highlyimprudent practice. Grease an
46、d equipment manufacturers alikerecognize such practices will occur despite all warnings to thecontrary. Thus, both users and suppliers have a need to knowthe compatibility characteristics of the greases in question.5.2 There are two approaches to evaluating the compatibil-ity of grease mixtures. One
47、 is to determine whether suchmixtures meet the same specification requirements as theconstituent components. This approach is not addressed by thispractice. Instead, this practice takes a specification-independent approach; it describes the evaluation of compat-ibility on a relative basis using spec
48、ific test methods.5.2.1 Three test methods are used because fewer are notsufficiently definitive. For example, in one study, using100 000-stroke worked penetration for evaluation, 62 % of themixtures were judged to be compatible.5In a high-temperaturestorage stability study, covering a broader spect
49、rum of greasetypes, only one-third of the mixtures were compatible.5Thesestudies used different criteria to judge compatibility.5.2.2 Compatibility cannot be predicted with certainty fromforeknowledge of grease composition. Generally, greases hav-ing the same or similar thickener types will be compatible.Uncommonly, even greases of the same type, although nor-mally compatible when mixed, can be incompatible because ofincompatible additive treatments. Thus, compatibility needs tobe judged on a case-by-case basis.5.3 Two constituent greases are blended in s
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