1、Designation: D6080 10Standard Practice forDefining the Viscosity Characteristics of Hydraulic Fluids1This standard is issued under the fixed designation D6080; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. 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 all hydraulic fluids based either onpetroleum, synthetic, or naturally-occurring base stocks. It isnot inten
3、ded 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 viscosities at high temperature, thispractice uses mi
4、llimetre 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 referencetemperature of 40C and to temperatures from 50
5、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 beappropriate. Any need to expand the system should b
6、e evaluated on itsown merit.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.2. Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Vis
7、cos-ity)D2270 Practice for Calculating Viscosity Index from Kine-matic Viscosity at 40 and 100CD2422 Classification of Industrial Fluid Lubricants by Vis-cosity SystemD2983 Test Method for Low-Temperature Viscosity ofLubricants Measured by Brookfield ViscometerD5621 Test Method for Sonic Shear Stabi
8、lity of HydraulicFluidsE29 Practice for Using Significant Digits in Test 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 D
9、efinitions:3.1.1 densitythe mass per unit volume.3.1.2 hydraulic fluida 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 o
10、f a liquid.3.1.4.1 DiscussionKinematic viscosity is a measure of theresistance 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 v
11、aries with changing shear stress or shear rate.3.1.7 shear degradationthe 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
12、 to shear degradation.3.1.10 shear stressthe motivating force per unit 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
13、 flow of the liquid.3.1.12 viscosity index (VI)an arbitrary number used tocharacterize the variation of the kinematic viscosity of a fluidwith temperature.1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommitt
14、ee D02.N0.10on Specifications.Current edition approved May 1, 2010. Published August 2010. Originallyapproved in 1997. Last previous edition approved in 2007 as D608097 (2007).DOI: 10.1520/D6080-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
15、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, PA 15096-0001, http:/www.sae.org.1Copyright ASTM International, 100 Barr Ha
16、rbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Practice4.1 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 wi
17、th use, and reduce the in-service viscosity of the fluids.4.2 This practice provides uniform 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
18、40C is determined in the worst case, that is, most severesituation, by the sheared oil viscosity, 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 tempera
19、ture viscosities do not de-crease greatly, if at all, with polymer shear degradation.Furthermore, 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 hydraul
20、ic fluids. This provides the user with amore reasonable basis to compare fluids than previous 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
21、fluidperformance. This permits lubricant suppliers, lubricant users,and equipment designers 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 D2422. Ra
22、ther, it is an enhancement intended toprovide a better description of the viscosity characteristics 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 int
23、ended for other functional fluids, thispractice may be useful in high-shear-stress applications 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 alr
24、eady exist, for ex-ample, SAE J300 for automotive engine oils and SAE J306 foraxle and manual 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 D2983.6.1.1 The viscosity shall
25、be interpolated from measurementsat three temperatures spanning the temperature at which 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 D29
26、83 iscurrently stated to be 1000 mPas. This equipment limitation isshown in Table 1 of that test method. Newer equipment isavailable which permits measurement of lower viscosities andTest Method D2983 is currently being revised with a lowerviscosity limit of 500 mPas.6.1.3 The temperature determined
27、 in 6.1.1 shall be roundedto a whole number in accordance with Practice E29.6.1.4 The low 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 vis
28、cosity (Test Method D445) of a fluidwhich has been sheared using Test Method D5621.6.2.1 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 temperat
29、ure viscositydesignation is the 40C kinematic viscosity (Test MethodD445) of the new 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, orvariabili
30、ty in kinematic viscosity or shear stability measure-ments), the lower designation must 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 D2270 onfluid which has been sheared using Test Method D5
31、621.6.3.1 The viscosity index determined in 6.3 shall be roundedto the nearest ten 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 D2270.
32、The viscosity index designation for the fluid isestablished by rounding this viscosity index to the nearest tenunits in accordance with Practice E29.NOTE 2The guidelines for rounding viscosity in 6.2.1 and 6.2.2 andviscosity index in 6.3.1 and 6.3.2 are specific to this practice and shouldnot be con
33、fused with the larger number of significant figures that can bereported when Test Methods D445 and D2270 are used for other purposes.TABLE 1 Low Temperature Viscosity Grades for Hydraulic FluidClassificationsViscosity GradeTemperature, C, for Brookfield Viscosityof 750 mPasAmin maxL5 . 50L7 49 42L10
34、 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
35、sameas that for an ISO VG 10 grade with a viscosity index of 100.D6080 1026.3.3 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
36、of spread in basestock or component specifications, or variability in kinematicviscosity 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 hydrauli
37、c fluids, the follow-ing designation shall be used:ISO VG xxLyy-zz (VI)where xx is the new oil viscosity grade as determined byClassification D2422 (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;
38、 and VI isthe viscosity index designation as determined in 6.3.6.4.1 If the new oil viscosity does not meet a gradedescribed by Classification D2422, 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 otherdescripto
39、rs for the new oil is at the discretion of the fluidmarketer.6.4.2 Examples 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
40、meetsthe requirements for the viscosity designation on the container.7. 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 temperat
41、ure range over which that fluidmay be used in that equipment.7.2 The low 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 determine
42、d by comparingthe Lyy designation with the corresponding temperature inTable 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. Henc
43、e, in equipmentwhich has a low temperature start-up viscosity limit of 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 viscosi
44、ty of 750 mPas at atemperature between 2 and 7C. Hence, in equipment whichhas 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.
45、 However, theprocess described in 6.1 can be used to determine lowtemperature 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
46、 hightemperature operating limits (Fig. 1 and Fig. 2) and optimumoperating 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 horizon
47、tal axis labeled HighTemperature Viscosity Designation.7.3.1.2 Read vertically 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,
48、for a KinematicViscosity of 10 (or 13) mm2/s. This is the upper temperaturelimit 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 viscosit
49、y minimum of 13 mm2/s; hence, Fig.2 should be used. As described in 7.3.1.1, 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 equ
