1、Designation: D6185 11 (Reapproved 2017)Standard 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
2、, 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 practice covers a protocol for evaluating thecompatibility of one or three binary mixtures of lubri
3、catinggreases by comparing 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
4、 Methods D217, 100 000-stroke 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
5、need for additional 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 lubri
6、cating greases havingcharacteristics 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 th
7、is would be when the 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
8、are to be regarded asstandard. No other units of measurement are included in thisstandard.1.7 This 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, health, and envir
9、onmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific safety information, see 7.2.3.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles
10、for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D217 Test Methods for Cone Penetration of LubricatingGreaseD566 Test Method for Dropping Point of Lu
11、bricating GreaseD972 Test Method for Evaporation Loss of LubricatingGreases and OilsD1092 Test Method for Measuring Apparent Viscosity ofLubricating GreasesD1263 Test Method for Leakage Tendencies of AutomotiveWheel Bearing Greases (Withdrawn 2010)3D1264 Test Method for Determining the Water Washout
12、Characteristics of Lubricating GreasesD1403 Test Methods for Cone Penetration of LubricatingGrease 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
13、Method for Determining Corrosion PreventiveProperties of Lubricating GreasesD1831 Test Method for Roll Stability of Lubricating GreaseD2265 Test Method for Dropping Point of LubricatingGrease Over Wide Temperature Range1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProduc
14、ts, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-mittee D02.G0.01 on Chemical and General Laboratory Tests.Current edition approved Dec. 15, 2017. Published February 2018. Originallyapproved in 1997. Last previous edition approved in 2011 as D6185 11. DOI:10.1520/D6185-11R
15、17.2For 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.3The last approved version of this historical standard is
16、referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles f
17、or theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1D2266 Test Method for Wear Preventive Characteristics ofLubricating Grease (Four-Ball Method)D2509 Test Method for Measurement of Load-Carrying
18、Capacity of Lubricating Grease (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 BallBeari
19、ngs at Elevated TemperaturesD3337 Test Method for Determining Life and Torque ofLubricating Greases in Small Ball Bearings (Withdrawn2009)3D3527 Test Method for Life Performance of AutomotiveWheel Bearing GreaseD4049 Test Method for Determining the Resistance ofLubricating Grease to Water SprayD4170
20、 Test Method for Fretting Wear Protection by Lubri-cating GreasesD4175 Terminology Relating to Petroleum Products, LiquidFuels, and LubricantsD4290 Test Method for Determining the Leakage Tenden-cies of Automotive Wheel Bearing Grease Under Accel-erated ConditionsD4425 Test Method for Oil Separation
21、 from LubricatingGrease by Centrifuging (Koppers Method)D4693 Test Method for Low-Temperature Torque of Grease-Lubricated Wheel BearingsD4950 Classification and Specification for Automotive Ser-vice GreasesD5706 Test Method for Determining Extreme PressureProperties of Lubricating Greases Using a Hi
22、gh-Frequency, Linear-Oscillation (SRV) Test MachineD5707 Test Method for Measuring Friction and Wear Prop-erties of Lubricating Grease Using a High-Frequency,Linear-Oscillation (SRV) Test Machine2.2 Federal Standard:Federal Test Method 3467.1 (Standard 791C), Storage Sta-bility of Lubricating Grease
23、43. Terminology3.1 Definitions:3.1.1 bleed (bleeding), nof lubricating greases, the sepa-ration of a liquid lubricant from a lubricating 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
24、 semifluid to solid product ofa dispersion of a thickener in a liquid lubricant.3.1.3.1 DiscussionThe dispersion of the thickener forms atwo-phase system and immobilizes the liquid lubricant bysurface tension and other physical forces. Other ingredientsimparting special properties are often included
25、. D2173.1.4 spatulate, vto mix or blend by spreading and foldingwith a flat thin, usually metal, tool.3.1.5 syneresis, nof lubricating 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 bleed
26、ing causedby physical or chemical changes of the thickness. Separation offree oil or the formation of cracks that occur in lubricatinggreases during storage in containers is most often due tosyneresis.3.1.6 thickener, nin a lubricating grease, a substancecomposed of finely divided particles disperse
27、d in a liquidlubricant to form the products structure.3.1.6.1 DiscussionThe thickener can be fibers (such asvarious metallic soaps) or 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
28、are that the solid particles be extremely small, uniformlydispersed, and capable of forming a relatively stable, gel-likestructure with 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 greas
29、es to be mixed together withoutsignificant degradation of properties or performance.3.2.1.1 DiscussionWhen a mixture of two greases hasproperties or performance significantly inferior to both of theneat, constituent greases, then the two greases are incompat-ible. If the properties are inferior to t
30、hose of one neat grease butnot inferior to those of the other, then such is not necessarilyconsidered an indication of incompatibility. 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
31、 the test method used to evaluatethe property (see pass and fail). Incompatibility most often ismanifested by a degradation in physical properties rather thanin chemical properties, although, occurrence of the latter is notunknown.3.2.2 borderline compatibility, nof lubricating greases,the character
32、istic of lubricating greases to be mixed togetherwith only slight degradation of properties or performance.3.2.2.1 DiscussionSlight degradation 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
33、 method used to evaluate the property. (Seeborderline pass.)3.2.3 primary compatibility tests, nof lubricating greases,those test methods employed first to evaluate compatibility.3.2.3.1 DiscussionThe test methods considered the mostsignificant in the evaluation of grease compatibility, insofar asth
34、ey provide the most information with the least expenditure oftesting resources, include tests for dropping point, consistency(usually softening) after shearing conditions, and consistencychange after storage at elevated temperatures.3.2.4 secondary compatibility tests, nof lubricatinggreases, those
35、test methods used to evaluate compatibilitywhen the primary compatibility tests are insufficient or incon-clusive.3.2.4.1 DiscussionSuch tests are driven by the criticalfeatures of a given application. For example, if the application4Available from Standardization Documents Order Desk, Bldg. 4, Sect
36、ion D,700 Robbins Ave., Philadelphia, PA 191115094, Attn: NPODS.D6185 11 (2017)2subjects 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 not required, by thi
37、s 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 poorer of thetwo const
38、ituent greases by an amount not exceeding therepeatability of the test method used for the evaluation.3.2.6.1 DiscussionBorderline pass, borderline fail, bor-derline compatible, and borderline incompatible are synony-mous terms.3.2.7 fail, nin compatibility testing of grease mixtures, atest result t
39、hat is inferior to that of the poorer of the twoconstituent greases by an amount exceeding the repeatability ofthe test method used for the evaluation.3.2.8 50:50 mixture, na uniform blend of 50 % by mass ofeach of two component greases.3.2.9 10:90 mixture, na uniform blend of 10 % by mass ofone gre
40、ase with 90 % by mass of a second grease.3.2.10 90:10 mixture, na uniform blend of 90 % by massof one grease with 10 % by mass of a second grease.4. Summary of Practice4.1 Option 1A 50:50 mixture of two greases to beevaluated for compatibility is prepared by spatulating. Thismixture and the two neat
41、, constituent greases are tested usingthe primary compatibility tests (dropping point, 100 000-strokeworked penetration, and change in 60-stroke penetration due tohigh-temperature storage). Depending on the performance ofthe mixture, relative to those of the constituent greases, 10:90and 90:10 mixtu
42、res may need to be tested in addition.Alternatively, Option 2 can be used. Instead of testing mixturesin sequential order, 10:90 and 90:10 mixtures are tested at thesame time the 50:50 mixture is evaluated. If all mixtures passthe primary compatibility tests, or if the application requiresthe evalua
43、tion of specific properties, secondary compatibilitytests can be employed for further evaluation. Such tests can berun concurrently, if desired.5. Significance and Use5.1 The compatibility of greases can be important for usersof grease-lubricated equipment. It is well known that themixing of two gre
44、ases can produce a substance markedlyinferior to either of its constituent materials. One or more of thefollowing can occur. A mixture of incompatible greases mostoften softens, sometimes excessively. Occasionally, it canharden. In extreme cases, the thickener and liquid lubricant willcompletely sep
45、arate. Bleeding can be so severe that the mixedgrease will run out of an operating bearing. Excessive syneresiscan occur, forming pools of liquid lubricant separated from thegrease. Dropping points can be reduced to the extent thatgrease or separated oil runs out of bearings at elevatedoperating tem
46、peratures. Such events can lead to catastrophiclubrication failures.5.1.1 Because of such occurrences, equipment manufactur-ers recommend completely cleaning the grease from equipmentbefore installing a different grease. Service recommendationsfor grease-lubricated equipment frequently specify the c
47、ave-atdo not mix greases under any circumstances. Despite thisadmonition, grease mixing will occur and, at times, cannot beavoided. In such instances, it would be useful to know whetherthe mixing of two greases could lead to inadequate lubricationwith disastrous consequences. Equipment users most of
48、ten donot have the resources to evaluate grease compatibility andmust rely on their suppliers. Mixing of greases is a highlyimprudent practice. Grease and equipment manufacturers alikerecognize such practices will occur despite all warnings to thecontrary. Thus, both users and suppliers have a need
49、to knowthe compatibility characteristics of the greases in question.5.2 There are two approaches to evaluating the compatibil-ity of grease mixtures. One 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 specific test methods.5.2.1 Three test methods are used because fewer are notsufficiently definitive. For exampl
