1、Designation: D 6080 97 (Reapproved 2002)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 is applicable to all hydraulic fluids basedeither on petroleum, s
3、ynthetic, or naturally-occurring basestocks. It is not 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 determinat
4、ion of viscosities 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 a
5、t a referencetemperature 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
6、may not beappropriate. Any need to expand the system should be evaluated on itsown merit.2. Referenced Documents2.1 ASTM Standards:D 445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and the Calculation of DynamicViscosity)2D 2270 Practice for Calculating Viscosity Index from
7、 Kine-matic Viscosity at 40 and 100C2D 2422 Classification of Industrial Fluid Lubricants byViscosity System2D 2983 Test Method for Low-Temperature Viscosity ofLubricants Measured by Brookfield Viscometer2D 5621 Test Method for Sonic Shear Stability of HydraulicFluids3E 29 Practice for Using Signifi
8、cant Digits in Test Data toDetermine Conformance with Specifications42.2 Society of Automotive Engineers (SAE) Standards:5J300 Engine Oil Viscosity ClassificationJ306 Axle and Manual Transmission Lubricant ViscosityClassification3. Terminology3.1 Definitions:3.1.1 viscositythe ratio between the appl
9、ied shear stressand shear rate.3.1.1.1 DiscussionViscosity is sometimes called the coef-ficient of dynamic viscosity. This coefficient is a measure of theresistance to flow of the liquid.3.1.2 kinematic viscositythe ratio of the viscosity to thedensity of a liquid.3.1.2.1 DiscussionKinematic viscosi
10、ty is a measure of theresistance to flow of a liquid under gravity.3.1.3 shear stressthe motivating force per unit area forfluid flow.3.1.4 shear ratethe velocity gradient in fluid flow.3.1.5 Newtonian fluida fluid that at a given temperatureexhibits a constant viscosity at all shear rates or shear
11、stresses.3.1.6 non-Newtonian fluida fluid that exhibits a viscositythat varies with changing shear stress or shear rate.3.1.7 densitythe mass per unit volume.3.1.8 hydraulic fluida fluid used in hydraulic systems fortransmitting power.3.1.9 viscosity index (VI)an arbitrary number used tocharacterize
12、 the variation of the kinematic viscosity of a fluidwith temperature.3.1.10 shear degradationthe decrease in molecularweight of a polymeric thickener (VI improver) as a result ofexposure to high shear stress.3.1.11 in-service viscositythe viscosity of fluid duringoperation of a hydraulic pump or cir
13、cuit components.3.1.12 shear stabilitythe resistance of a polymer-thickened fluid to shear degradation.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. Thes
14、e1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.N0 onHydraulic Fluids.Current edition approved Dec. 10, 2002. Published March 2003. Originallyapproved in 1997. Last previous edition approved in 1
15、997 as D 6080 97.2Annual Book of ASTM Standards, Vol 05.01.3Annual Book of ASTM Standards, Vol 05.03.4Annual Book of ASTM Standards, Vol 14.02.5Available from Society of Automotive Engineers, 400 Commonwealth Dr.,Warrendale, PA 15096.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700,
16、 West Conshohocken, PA 19428-2959, United States.polymers may shear degrade with 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
17、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 viscosity, the viscosity andviscosity index used to characterize fluids in this practice arethose of the sheared fluid.4.2.2 This pract
18、ice classifies oils at low temperature by theirnew oil properties. Low temperature 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 n
19、ew.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 previous prac-tices.5. Significance and Use5.1 The purpose of this practice is to establish viscositydesignations derived from viscositie
20、s measured by test meth-ods which have a meaningful relationship to hydraulic 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
21、 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 characteristics oflubricants used as hydraulic fluids.5.3 This practice implies no evaluation of hydraulic oilquality other than its visc
22、osity 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 applications whereviscosity index (VI) improvers are used to extend the usefuloperating temperature range of the fluid.5.5 This practice d
23、oes 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 manual transmission lubricants.6. Procedure6.1 The low temperature viscosity grade of a fluid is basedon the viscosity of new oil meas
24、ured using a Brookfieldviscometer, Test Method D 2983.6.1.1 The viscosity shall 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
25、 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 that method. Newer equipment is availablewhich permits measurement of lower viscosities and TestMethod D 2983 is currently being rev
26、ised 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 E 29.6.1.4 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
27、 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 5621.6.2.1 The kinematic viscosity determined in 6.2 shall berounded to a whole number in accordance with Practice E 29.6.2.2 For a fluid know
28、n 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 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,
29、 it variesbecause of spread in base stock or component specifications, orvariability 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 d
30、etermined 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 units in accordance with Practice E 29. Thisvalue is the viscosity index designation.6.3.2 For fluids which do not contain polymeric
31、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 viscosity index to the nearest tenunits in accordance with Practice E 29.NOTE 2The guidelines for rounding viscosity in 6.2.1 and 6.2.2 a
32、ndviscosity 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 otherpurposes.6.3.3 If the viscosity index fails to meet the same designa-tion consistently,
33、that is, it varies between the lower values forone designation and the higher values for the next lowerTABLE 1 Low Temperature Viscosity Grades for Hydraulic FluidClassificationsViscosity GradeTemperature, C, for Brookfield Viscosityof 750 mPasAmin maxL5 . 50L7 49 42L10 41 33L15 32 23L22 22 15L32 14
34、 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 sameas that for an ISO VG 10 g
35、rade with a viscosity index of 100.D 6080 97 (2002)2designation (for example, it varies because 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
36、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)where xx is the new oil viscosity grade as determined byClassification D 2422 (Table 2); Lyy is the low temperatureviscosity grade as
37、 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 the new oil viscosity does not meet a gradedescribed by Classification D 2422, the ISO VG xx portion ofthe designation does not app
38、ly. 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 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
39、 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. Interpretation of Results7.1 The designation determined for a hydraulic fluid asdescribed in 6.4 may be used in combination with a
40、 manufac-turers viscosity recommendations for specific equipment toestimate an acceptable temperature 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 equipm
41、ent 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 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 toT
42、able 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 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
43、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 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 pr
44、actice is not quantitative when a manufacturerspecifies lower or higher start-up viscosity limits. 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
45、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 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 k
46、inematic 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 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.
47、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 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 a
48、nd 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 7.3.1.1, find the value 40 onthe horizontal axis labeled High Temperature Viscosity Desig-nation. As described in 7.3.1.2, read vertic
49、ally 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, fluid temperature for the oil in this example should notexceed 75C.7.3.1.5 Example 2bFor the oil in Example 2a in 7.2.3, thehigh te
