1、Designation: D 7342 07An American National StandardStandard Test Method forShear Stability of Lubricating Grease in Presence of Water(Water Stability Test)1This standard is issued under the fixed designation D 7342; the number immediately following the designation indicates the year oforiginal adopt
2、ion 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 two procedures for determiningthe shear stabilit
3、y of lubricating grease in the presence of water(wet shear stability) by a full scale grease worker or a rollstability test apparatus. Both procedures can be used todetermine the relative wet shear stability of greases, but theresults between procedures are not directly comparable. Thistest method i
4、s also known as the water stability test.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of t
5、he user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 217 Test Methods for Cone Penetration of LubricatingGreaseD 1403 Test Methods for Cone Penetration of Lu
6、bricatingGrease Using One-Quarter and One-Half Scale ConeEquipmentD 1831 Test Method for Roll Stability of LubricatingGreaseD 1193 Specification for Reagent Water3. Terminology3.1 Definitions:3.1.1 consistency, nof lubricating grease, degree of resis-tance to movement under stress.3.1.1.1 Discussion
7、The term consistency is used some-what synonymously with penetration. Generally, consistencyrefers to the worked penetration of a grease. D 2173.1.2 lubricating grease, nsemi-fluid to solid product of adispersion of a thickener in a liquid lubricant.3.1.2.1 DiscussionThe dispersion of the thickener
8、forms atwo-phase system and immobilizes the liquid lubricant bysurface tension and other physical forces. Other ingredients arecommonly included to impart special properties. D 2173.1.3 penetration, nof lubricating grease, depth that thestandard cone, when released to fall under its own weight for5
9、s, enters the sample. D 2173.1.4 thickener, nin lubricating grease, substance com-posed of finely divided particles dispersed in a liquid lubricantto form the products structure.3.1.4.1 DiscussionThe thickener can be fibers (such asvarious metallic soaps) or plates or spheres (such as certainnon-soa
10、p thickener) which are insoluble or, at most, only veryslightly soluble in liquid lubricant. The general requirementsare that the solid particles to be relatively stable, gel-likestructure with the liquid lubricant. D 2173.1.5 wet shear stability, nof lubricating grease, changein consistency of a mi
11、xture of sample and small amount ofwater after a specified amount of working in a grease worker ora roll stability test apparatus.3.1.6 worked penetration, nof lubricating grease, thepenetration at 25C, without delay, of a sample after 60 doublestrokes in a standard grease worker. D 2173.1.7 working
12、, nof lubricating grease, subjection of asample to the shearing action of the standard grease worker.D 2174. Summary of Test Method4.1 A grease sample mixed with a small amount of water issubjected to low shear at 20 to 35C for a specified time orstrokes in a standard grease worker (Procedure A) or
13、a rollstability apparatus (Procedure B). The difference between thecone penetration before working and the cone penetration afteris used as a measure of the wet shear stability of the grease.5. Significance and Use5.1 It is known that contamination by water can affect theshear stability of some grea
14、ses in service. Both test proceduresspecified in this method are widely used to determine the wetshear stability of greases in service. Many grease specifications1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of
15、SubcommitteeD02.G0.07 on Research Techniques.Current edition approved May 1, 2007. Published May 2007.2For 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
16、Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.require these procedures as a wet shear stability test. Noaccurate correlation is established between the test results andwet shear stability of
17、 grease in actual service.6. Apparatus6.1 Motorized Grease Worker, as specified in Test MethodsD 217.6.2 Roll Stability Test Apparatus, as specified in TestMethod D 1831.6.3 Penetrometer, as specified in Test Methods D 217.6.4 One-Quarter or One-Half Scale Cone and Shaft withWorker, as described in
18、Test Methods D 1403.6.5 Electric Kitchen-type mixer, Low speed of 500 rpm.6.6 Suitable Mixing Bowl.7. Reagents and Materials7.1 Appropriate Volatile Gum-free Solvent, for example,mineral spirit solvent.7.2 Cloth or Paper Wiper, for wiping grease from thepenetrometer cone. The wiper should be soft, s
19、o as not toscratch the cone.7.3 Distilled Water, Specification D 1193, Type II minimumpurity.8. ProcedureProcedure AWet Prolonged Worked Test8.1 Measure the worked penetration for the grease to betested according to Test Methods D 217.8.2 For each determination, prepare a homogeneous mix-ture of gre
20、ase and water by placing 450 6 1 g of grease and 506 1 g of distilled water in a suitable mixing bowl using anelectric kitchen-type mixer or mixing by hand in a suitablecontainer.8.2.1 Gradually add the calculated amount of distilled waterto the grease in the bowl.8.2.2 Mix the contents for 4 6 1 mi
21、n.Aspatula may be usedto channel the constituents to the mixer.8.2.3 The objective of foregoing sections is to produce amixture of nine parts of grease and one part of water thattransfer to a worker cup.NOTE 1If free water is observed after mixing, then additional mixingis required.8.3 Fill a standa
22、rd Test Methods D 217 grease worker withthe mixture and work the sample on a motorized grease workerfor 100 000 double strokes (approximately 28 h). After work-ing is completed, bring the grease worker and the sample to 256 0.5C in accordance with the procedure described in TestMethods D 217 for pro
23、longed worked penetration.8.4 Immediately after the grease sample reaches 25 60.5C, rework the sample an additional 60 double strokes.Determine the worked penetration.Procedure BWet Shell Roll Test8.5 Determine the worked penetration of the grease to betested in accordance with Test Methods D 1403.8
24、.6 Transfer 63.0 6 0.2 g of unworked grease to testcylinder. Distribute the grease uniformly on the inside wall ofthe cylinder with a spatula.8.7 Place the weighed roll in the cylinder.8.8 Add 7.0 6 0.2 g distilled water to the cylinder, andtighten the cap.8.9 Mount the cylinder in position, start t
25、he machine, andrecord the time and room temperature which should be limitedto 20 to 35C. If the cylinder is enclosed within a cabinet, thetemperature around cylinder shall be maintained at 20 to 35C.8.10 After rolling the cylinder for 2 h 6 5 min, remove thegrease from the cylinder promptly and proc
26、eed with therequirements of worked penetration in Test Methods D 1403.Record the worked penetration. After transferring the grease tothe worker, clean the test apparatus by wiping with clean clothor tissue.8.11 Convert the fractional scale penetration values deter-mined by Test Methods D 1403 (befor
27、e and after test) into theequivalent full scale cone penetration values using the appro-priate equations described in Test Methods D 1403.9. Calculation9.1 Calculate the change in consistency of the sample asfollows:Penetration change 5 P22 P1(1)where:P2= final full-scale penetration reading, andP1=
28、 initial full-scale penetration reading.NOTE 2Penetration reading is measured in tenths of a millimetre. Anegative penetration change indicates hardening of grease while a positivepenetration change indicates softening.10. Report10.1 The value calculated in 9.1 is reported with the testprocedure as
29、the wet shear stability of the grease. For Proce-dure B, a notation if free water is present is useful information.11. Precision and Bias11.1 PrecisionThe precision of this test method as deter-mined by a statistical examination of interlaboratory test resultsshown in Tables 1 and 2. Their round rob
30、in samples are listedin Table 3.11.1.1 RepeatabilityThe difference between successiveresults obtained by the same operator with the same apparatusunder constant operating conditions on identical test materialswould, in the long run, in normal and correct operation of thetest method exceed the follow
31、ing values only in one case intwenty:Procedure A 20 unitsProcedure B 18 units11.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories on identical test material would, inthe long run, in the normal and correct o
32、peration of the testmethod, exceed the following values only in one case intwenty:Procedure A 26 unitsProcedure B 31 unitsD734207211.2 BiasThe interlaboratory tests confirm that there is asignificant bias between Procedure A and Procedure B in thistest method. Both procedures can be used to determin
33、e therelative wet shear stability of greases, but the results betweenprocedures are not directly comparable.TABLE 1 Round Robin Test Results for Procedure ALabSampleS1 S2 S3 S4 S51+25 +122 +100 +55 +29+24 +126 +103 +60 +322+11 +117 +88 +72 +250 +112 +90 +71 +283+154 +107 +97 +62 +24+159 +118 +99 +53
34、 +74+1 +120 +97 +53 +27+6 +123 +96 +80 +275+29 +115 +86 +54 +28+12 +114 +109 +63 +286+25 +95 +99 +49 +25+20 +88 +104 +44 +317+11 +117 +79 +48 +25-2 +89 +92 +61 +2380 +117 +96 +62 +36+3 +122 +88 +68 +339+11 +118 +100 +59 +18+17 +113 +87 +64 +2010+11 +108 . +70 +32+10 +91 . +67 +37TABLE 2 Round Robin
35、Test Results for Procedure BLabSampleS1 S2 S3 S4 S51-3 +32 +64 +40 +24+2 +16 +68 +39 +232+4 +38 +54 +52 +18+3 +48 +60 +37 +263+26 -12 +52 +22 +3+12 0 +50 +38 -24-18 +26 +38 +37 +2-21 +29 +39 +42 +275+8 +64 +58 +40 +24+4 +26 +60 +36 +206-6 +44 +55 +36 +20-2 +37 +58 +34 +247-12 +60 +30 +32 +12-4 +60 +
36、52 +26 +108+2 +42 +58 +40 +200 +50 +62 +44 +229+30 +79 +41 +26 +19+19 +90 +33 +22 +2210+2 +50 . +20 +10+10 +52 . +48 +12D734207312. Keywords12.1 cone penetration; consistency; grease worker; lubricat-ing grease; penetration; roll stability; water stability test; wetshear stabilityASTM International
37、takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own
38、 responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be add
39、ressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at
40、 the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 3 Round Robin SamplesSample Code NLGI Grade Thickener TypeS1 2 Al-complexS2 3 LithiumS3 2 PolyureaS4 1 LithiumS5 1 Li-complexD7342074
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