1、Designation: D6080 12Standard 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. Scope*1.1 This practice covers all hydraulic fluids based either onpetroleum, synthetic, or naturally-occurring base stocks. It isnot inte
3、nded 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 m
4、illimetre 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
6、be 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 Vi
7、scos-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 of Lu-bricants Measured by Brookfield ViscometerD5621 Test Method for Sonic Shear St
8、ability 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.
9、1 Definitions:3.1.1 density, nthe mass per unit volume.3.1.2 hydraulic fluid, na fluid used in hydraulic systemsfor transmitting power.3.1.3 in-service viscosity, nthe viscosity of fluid duringoperation of a hydraulic pump or circuit components.3.1.4 kinematic viscosity, nthe ratio of the viscosity
10、to thedensity of a liquid.3.1.4.1 DiscussionKinematic viscosity is a measure of theresistance to flow of a liquid under gravity.3.1.5 Newtonian fluid, na fluid that at a given temperatureexhibits a constant viscosity at all shear rates or shear stresses.3.1.6 non-Newtonian fluid, na fluid that exhib
11、its a viscos-ity that varies with changing shear stress or shear rate.3.1.7 shear degradation, nthe decrease in molecularweight of a polymeric thickener (VI improver) as a result ofexposure to high shear stress.3.1.8 shear rate, nthe velocity gradient in fluid flow.3.1.9 shear stability, nthe resist
12、ance of a polymer-thickened fluid to shear degradation.3.1.10 shear stress, nthe motivating force per unit area forfluid flow.3.1.11 viscosity, nthe ratio between the applied shearstress and shear rate.3.1.11.1 DiscussionViscosity is sometimes called the co-efficient of dynamic viscosity. This coeff
13、icient is a measure ofthe resistance to flow of the liquid.1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.N0.10on Specifications.Current edition approved June 1, 2012. Published August 2012. Orig
14、inallyapproved in 1997. Last previous edition approved in 2010 as D608010. DOI:10.1520/D6080-12.2For 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 Docume
15、nt Summary page onthe ASTM website.3Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoho
16、cken, PA 19428-2959. United States13.1.12 viscosity index (VI), nan arbitrary number used tocharacterize the variation of the kinematic viscosity of a fluidwith temperature.4. Summary of Practice4.1 High VI hydraulic fluids often contain high molecularweight thickeners, called viscosity index (VI) i
17、mprovers,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 uniform guidelines for character-izing oils in terms of both their high and low temperatureviscosities before and a
18、fter 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 viscosity, the viscosity andviscosity index used to characterize fluids in this practice arethose of the sheared
19、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.Furthermore, this approach ensures that the fluid will beproperly classified under the worst-case conditions, that
20、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 previous prac-tices.5. Significance and Use5.1 The purpose of this practice is to establish viscositydesignations d
21、erived from viscosities 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 o
22、f hydraulic fluids.5.2 This practice is not intended to be a replacement forClassification D2422. 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 oilqualit
23、y 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 applications whereviscosity index (VI) improvers are used to extend the usefuloperating temperature range of the flui
24、d.5.5 This practice does not apply to other lubricants forwhich viscosity classification systems already exist, forexample, SAE J300 for automotive engine oils and SAE J306for axle and manual transmission lubricants.6. Procedure6.1 The low temperature viscosity grade of a fluid is basedon the viscos
25、ity of new oil measured using a Brookfieldviscometer, Test Method D2983.6.1.1 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 temperatu
26、re atwhich the oil has a viscosity of 750 mPas.6.1.2 The temperature determined in 6.1.1 shall be roundedto a whole number in accordance with Practice E29.6.1.3 The low temperature viscosity grade is determined bymatching the temperature determined in 6.1.2 with the require-ments shown in Table 1.6.
27、2 The high temperature viscosity designation of a fluid isthe 40C kinematic viscosity (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
28、to contain no polymeric compo-nents which will shear degrade, the high temperature 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
29、 variesbecause of spread in base stock or component specifications, orvariability in kinematic viscosity or shear stabilitymeasurements), the lower designation must be used to ensureconformance with 6.5 below.6.3 The viscosity index designation of the fluid is based onthe viscosity index as determin
30、ed using Practice D2270 onfluid which has been sheared using Test Method D5621.6.3.1 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 polymericcomponents,
31、 the viscosity index is determined on the new fluidusing Practice D2270. The viscosity index designation for thefluid is established by rounding this viscosity index to thenearest ten units in accordance with Practice E29.NOTE 2The guidelines for rounding viscosity in 6.2.1 and 6.2.2 andviscosity in
32、dex 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 D445 and D2270 are used for other purposes.TABLE 1 Low Temperature Viscosity Grades for Hydraulic FluidClassificationsViscosity GradeTemp
33、erature, C, for Brookfield Viscosityof 750 mPasAmin maxL5 . 50L7 49 42L10 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 that foran ISO grade of the same numerical designation and having a viscosity index of10
34、0, that is, the temperature range for the L10 grade is approximately the same asthat for an ISO VG 10 grade with a viscosity index of 100.D6080 1226.3.3 If the viscosity index fails to meet the same designa-tion consistently, that is, it varies between the lower values forone designation and the hig
35、her values for the next lowerdesignation (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 the sake of uniformity
36、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 D2422 (Table 2); Lyy is the low temperatureviscosity grade as determined in 6.1; zz i
37、s 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 D2422, the ISO VG xx portion ofthe designation does not apply. In such cases, the Ly
38、y-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 operation. However, it i
39、s 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 manufac-turers viscosity
40、 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 equipment with a start-up, unde
41、r 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 toTable 1 indicates that thi
42、s 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 low temperature grade is
43、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 practice is not quantitativ
44、e 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 index determined in 6.3,
45、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 kinematic viscosity limits
46、 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,interpolating, if necessary.7.3.1.3 Read horizontally from th
47、e 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 and 150, respec-tively. Assu
48、me 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 vertically from 40 untilintersect
49、ing the curve labeled VI = 150. Finally, as described in7.3.1.3, read horizontally to the vertical axis labeledTemperature, C, for a Kinematic Viscosity of 13 mm2/s. Thevalue corresponding to a high temperature viscosity designa-tion of 40 and a viscosity index of 150 is 75C. Hence, inequipment which has a recommended kinematic viscosityminimum of 13 mm2/s, fluid temperature for the oil in thisexample should not exceed 75C.7.3.1.5 Example 2bFor the oil in Example 2a in 7.2.3, thehigh temperature designation and VI
