ASTM D6080-1997(2007) 431 Standard Practice for Defining the Viscosity Characteristics of Hydraulic Fluids.pdf

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1、Designation: D 6080 97 (Reapproved 2007)An American National StandardStandard Practice forDefining the Viscosity Characteristics of Hydraulic Fluids1This standard is issued under the fixed designation D 6080; the number immediately following the designation indicates the year oforiginal adoption or,

2、 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 practice covers all hydraulic fluids based either onpetroleum, synthetic,

3、or naturally-occurring base stocks. It isnot intended for water-containing hydraulic fluids.1.2 For determination of viscosities at low temperature, thispractice uses millipascalsecond (mPas) as the unit of viscos-ity. For reference, 1 mPas is equivalent to 1 centipoise (cP).For determination of vis

4、cosities at high temperature, thispractice uses millimetre squared per second (mm2/s) as the unitof kinematic viscosity. For reference, 1 mm2/s is equivalent to1 centistoke (cSt).1.3 This practice is applicable to fluids ranging in kinematicviscosity from about 4 to 150 mm2/s as measured at a refere

5、ncetemperature of 40C and to temperatures from 50 to +16Cfor a fluid viscosity of 750 mPas.NOTE 1Fluids of lesser or greater viscosity than the range describedin 1.3 are seldom used as hydraulic fluids.Any mathematical extrapolationof the system to either higher or lower viscosity grades may not bea

6、ppropriate. Any need to expand the system should be evaluated on itsown merit.2. Referenced Documents2.1 ASTM Standards:2D 445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D 2270 Practice for Calculating Viscosity Index from Kine-matic V

7、iscosity at 40 and 100CD 2422 Classification of Industrial Fluid Lubricants byViscosity SystemD 2983 Test Method for Low-Temperature Viscosity ofLubricants Measured by Brookfield ViscometerD 5621 Test Method for Sonic Shear Stability of HydraulicFluidsE29 Practice for Using Significant Digits in Tes

8、t Data toDetermine Conformance with Specifications2.2 Society of Automotive Engineers (SAE) Standards:3J300 Engine Oil Viscosity ClassificationJ306 Axle and Manual Transmission Lubricant ViscosityClassification3. Terminology3.1 Definitions:3.1.1 densitythe mass per unit volume.3.1.2 hydraulic fluida

9、 fluid used in hydraulic systems fortransmitting power.3.1.3 in-service viscositythe viscosity of fluid duringoperation of a hydraulic pump or circuit components.3.1.4 kinematic viscositythe ratio of the viscosity to thedensity of a liquid.3.1.4.1 DiscussionKinematic viscosity is a measure of theres

10、istance to flow of a liquid under gravity.3.1.5 Newtonian fluida fluid that at a given temperatureexhibits a constant viscosity at all shear rates or shear stresses.3.1.6 non-Newtonian fluida fluid that exhibits a viscositythat varies with changing shear stress or shear rate.3.1.7 shear degradationt

11、he decrease in molecular weightof a polymeric thickener (VI improver) as a result of exposureto high shear stress.3.1.8 shear ratethe velocity gradient in fluid flow.3.1.9 shear stabilitythe resistance of a polymer-thickenedfluid to shear degradation.3.1.10 shear stressthe motivating force per unit

12、area forfluid flow.3.1.11 viscositythe ratio between the applied shear stressand shear rate.3.1.11.1 DiscussionViscosity is sometimes called the co-efficient of dynamic viscosity. This coefficient is a measure ofthe resistance to flow of the liquid.1This practice is under the jurisdiction of ASTM Co

13、mmittee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.N0.10on Specifications.Current edition approved Nov. 1, 2007. Published January 2008. Originallyapproved in 1997. Last previous edition approved in 2002 as D 608097(2002).2For referenced ASTM standar

14、ds, 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.3Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, P

15、A 15096-0001, http:/www.sae.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.12 viscosity index (VI)an arbitrary number used tocharacterize the variation of the kinematic viscosity of a fluidwith temperature.4. Summary of Prac

16、tice4.1 High VI hydraulic fluids often contain high molecularweight thickeners, called viscosity index (VI) improvers,which impart non-Newtonian characteristics to the fluid. Thesepolymers may shear degrade with use, and reduce the in-service viscosity of the fluids.4.2 This practice provides unifor

17、m guidelines for character-izing oils in terms of both their high and low temperatureviscosities before and after exposure to high shear stress.4.2.1 Since the performance of fluids at temperatures higherthan 40C is determined in the worst case, that is, most severesituation, by the sheared oil visc

18、osity, the viscosity andviscosity index used to characterize fluids in this practice arethose of the sheared fluid.4.2.2 This practice classifies oils at low temperature by theirnew oil properties. Low temperature viscosities do not de-crease greatly, if at all, with polymer shear degradation.Furthe

19、rmore, this approach ensures that the fluid will beproperly classified under the worst-case conditions, that is,when the fluid is new.4.3 This practice may be used with either Newtonian ornon-Newtonian hydraulic fluids. This provides the user with amore reasonable basis to compare fluids than previo

20、us prac-tices.5. Significance and Use5.1 The purpose of this practice is to establish viscositydesignations derived from viscosities measured by test meth-ods which have a meaningful relationship to hydraulic fluidperformance. This permits lubricant suppliers, lubricant users,and equipment designers

21、 to have a uniform and common basisfor designating, specifying, or selecting the viscosity charac-teristics of hydraulic fluids.5.2 This practice is not intended to be a replacement forClassification D 2422. Rather, it is an enhancement intended toprovide a better description of the viscosity charac

22、teristics oflubricants used as hydraulic fluids.5.3 This practice implies no evaluation of hydraulic oilquality other than its viscosity and shear stability under theconditions specified.5.4 While it is not intended for other functional fluids, thispractice may be useful in high-shear-stress applica

23、tions whereviscosity index (VI) improvers are used to extend the usefuloperating temperature range of the fluid.5.5 This practice does not apply to other lubricants forwhich viscosity classification systems already exist, for ex-ample, SAE J300 for automotive engine oils and SAE J306 foraxle and man

24、ual transmission lubricants.6. Procedure6.1 The low temperature viscosity grade of a fluid is basedon the viscosity of new oil measured using a Brookfieldviscometer, Test Method D 2983.6.1.1 The viscosity shall be interpolated from measurementsat three temperatures spanning the temperature at which

25、theviscosity is 750 mPas. A smooth graph of these data (logviscosity versus temperature) determines the temperature atwhich the oil has a viscosity of 750 mPas.6.1.2 The lower viscosity limit for Test Method D 2983 iscurrently stated to be 1000 mPas. This equipment limitation isshown in Table 1 of t

26、hat test method. Newer equipment isavailable which permits measurement of lower viscosities andTest Method D 2983 is currently being revised with a lowerviscosity limit of 500 mPas.6.1.3 The temperature determined in 6.1.1 shall be roundedto a whole number in accordance with Practice E29.6.1.4 The l

27、ow temperature viscosity grade is determined bymatching the temperature determined in 6.1.3 with the require-ments shown in Table 1.6.2 The high temperature viscosity designation of a fluid isthe 40C kinematic viscosity (Test Method D 445) of a fluidwhich has been sheared using Test Method D 5621.6.

28、2.1 The kinematic viscosity determined in 6.2 shall berounded to a whole number in accordance with Practice E29.6.2.2 For a fluid known to contain no polymeric compo-nents which will shear degrade, the high temperature viscositydesignation is the 40C kinematic viscosity (Test MethodD 445) of the new

29、 fluid, rounded per 6.2.1.6.2.3 If the 40C kinematic viscosity from 6.2.1 fails tomeet the same designation consistently (for example, it variesbecause of spread in base stock or component specifications, orvariability in kinematic viscosity or shear stability measure-ments), the lower designation m

30、ust be used to ensure conform-ance with 6.5 below.6.3 The viscosity index designation of the fluid is based onthe viscosity index as determined using Practice D 2270 onfluid which has been sheared using Test Method D 5621.6.3.1 The viscosity index determined in 6.3 shall be roundedto the nearest ten

31、 units in accordance with Practice E29. Thisvalue is the viscosity index designation.6.3.2 For fluids which do not contain polymeric compo-nents, the viscosity index is determined on the new fluid usingPractice D 2270. The viscosity index designation for the fluidis established by rounding this visc

32、osity index to the nearest tenunits in accordance with Practice E29.NOTE 2The guidelines for rounding viscosity in 6.2.1 and 6.2.2 andTABLE 1 Low Temperature Viscosity Grades for Hydraulic FluidClassificationsViscosity GradeTemperature, C, for Brookfield Viscosityof 750 mPasAmin maxL5 . 50L7 49 42L1

33、0 41 33L15 32 23L22 22 15L32 14 8L46 7 2L68 1 4L100 5 10L150 11 16AThe temperature range for a given L-grade is approximately equivalent to thatfor an ISO grade of the same numerical designation and having a viscosity indexof 100, that is, the temperature range for the L10 grade is approximately the

34、 sameas that for an ISO VG 10 grade with a viscosity index of 100.D 6080 97 (2007)2viscosity index in 6.3.1 and 6.3.2 are specific to this practice and shouldnot be confused with the larger number of significant figures that can bereported when Test Methods D 445 and D 2270 are used for otherpurpose

35、s.6.3.3 If the viscosity index fails to meet the same designa-tion consistently, that is, it varies between the lower values forone designation and the higher values for the next lowerdesignation (for example, it varies because of spread in basestock or component specifications, or variability in ki

36、nematicviscosity or shear stability measurements), the lower designa-tion must be used to ensure conformance with 6.5 below.6.4 For the sake of uniformity of nomenclature in identify-ing the viscosity characteristics of hydraulic fluids, the follow-ing designation shall be used:ISO VG xxLyy-zz (VI)w

37、here xx is the new oil viscosity grade as determined byClassification D 2422 (Table 2); Lyy is the low temperatureviscosity grade as determined in 6.1; zz is the high temperaturesheared viscosity designation as determined in 6.2; and VI isthe viscosity index designation as determined in 6.3.6.4.1 If

38、 the new oil viscosity does not meet a gradedescribed by Classification D 2422, the ISO VG xx portion ofthe designation does not apply. In such cases, the Lyy-zz (VI)designation may still be used, and the use of any otherdescriptors for the new oil is at the discretion of the fluidmarketer.6.4.2 Exa

39、mples of use of this practice are shown in Table 3.6.5 An oil blender may use any manufacturing control thatseems appropriate to his operation. However, it is the respon-sibility of the blender to ensure that all production fully meetsthe requirements for the viscosity designation on the container.7

40、. Interpretation of Results7.1 The designation determined for a hydraulic fluid asdescribed in 6.4 may be used in combination with a manufac-turers viscosity recommendations for specific equipment toestimate an acceptable temperature range over which that fluidmay be used in that equipment.7.2 The l

41、ow temperature grade determined in 6.1, Lyy,defines the lowest recommended fluid temperature at which thefluid may be used in equipment with a start-up, under load limitof 750 mPas, max.7.2.1 The low temperature limit is determined by comparingthe Lyy designation with the corresponding temperature i

42、nTable 1.7.2.2 Example 1aFor an oil with the designation:ISO VG 46L32-40 ,the low temperature grade is defined by L32. Reference toTable 1 indicates that this oil has a viscosity of 750 mPas at atemperature between 8 and 14C. Hence, in equipmentwhich has a low temperature start-up viscosity limit of

43、 750mPas, the oil in this example may be used down to atleast 8C.7.2.3 Example 2aFor an oil with the designation:ISO VG 68L46-57the low temperature grade is defined by L46. Reference toTable 1 indicates that this oil has a viscosity of 750 mPas at atemperature between 2 and 7C. Hence, in equipment w

44、hichhas a low temperature start-up viscosity limit of 750 mPas, theoil in this example may be used down to at least 2C.7.2.4 This practice is not quantitative when a manufacturerspecifies lower or higher start-up viscosity limits. However, theprocess described in 6.1 can be used to determine lowtemp

45、erature limitations corresponding to any start-up viscosity.7.3 The high temperature designation determined in 6.2 andthe viscosity index determined in 6.3, zz (VI), can be used incombination with the data in Figs. 1-4 to estimate hightemperature operating limits (Fig. 1 and Fig. 2) and optimumopera

46、ting temperatures (Fig. 3 and Fig. 4) for the fluid.7.3.1 Fig. 1 and Fig. 2 apply directly to equipment whichhas minimum operating kinematic viscosity limits of 10 and 13mm2/s, respectively.7.3.1.1 Find the value zz on the horizontal axis labeled HighTemperature Viscosity Designation.7.3.1.2 Read ve

47、rtically from the point defined by 7.3.1.1 tothe curve corresponding to the viscosity index, VI, interpolat-ing, if necessary.7.3.1.3 Read horizontally from the point defined by 7.3.1.2to the vertical axis labeled Temperature, C, for a KinematicViscosity of 10 (or 13) mm2/s. This is the upper temper

48、aturelimit for fluid operation.7.3.1.4 Example 1bFor the oil in Example 1a in 7.2.2, thehigh temperature designation and VI are 40 and 150, respec-tively. Assume that the equipment of interest has a recom-mended kinematic viscosity minimum of 13 mm2/s; hence, Fig.2 should be used. As described in 7.

49、3.1.1, find the value 40 onthe horizontal axis labeled High Temperature Viscosity Desig-nation. As described in 7.3.1.2, read vertically from 40 untilintersecting the curve labeled VI = 150. Finally, as described in7.3.1.3, read horizontally to the vertical axis labeled Tempera-ture, C, for a Kinematic Viscosity of 13 mm2/s. The valuecorresponding to a high temperature viscosity designation of40 and a viscosity index of 150 is 75C. Hence, in equipmentwhich has a recommended kinematic viscosity minimum of 13mm2/s,