ASTM D6080-2018a Standard Practice for Defining the Viscosity Characteristics of Hydraulic Fluids.pdf

1、Designation: D6080 18D6080 18aStandard 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 la

2、st revision. 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 on petroleum, synthetic, or naturally-occurring base stocks. It

3、is notintended for water-containing hydraulic fluids.1.2 For determination of viscosities at low temperature, this practice uses millipascalsecond (mPas) as the unit of viscosity.For reference, 1 mPas is equivalent to 1 centipoise (cP). For determination of viscosities at high temperature, this prac

4、tice usesmillimetre squared per second (mm2/s) as the unit of kinematic viscosity. For reference, 1 mm2/s is equivalent to 1 centistoke (cSt).1.3 This practice is applicable to fluids ranging in kinematic viscosity from about 4 mm2/s to 150 mm2/s as measured at areference temperature of 40 C and to

5、temperatures from 50 C to +16 C for a fluid viscosity of 750 mPas.NOTE 1Fluids of lesser or greater viscosity than the range described in 1.3 are seldom used as hydraulic fluids. Any mathematical extrapolation ofthe system to either higher or lower viscosity grades may not be appropriate. Any need t

6、o expand the system should be evaluated on its own merit.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This international standard was developed in accordance with internationally recognized principles on standardiza

7、tionestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparen

8、t and Opaque Liquids (and Calculation of Dynamic Viscosity)D2270 Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 C and 100 CD2422 Classification of Industrial Fluid Lubricants by Viscosity SystemD2983 Test Method for Low-Temperature Viscosity of Automatic Transmission Fluids,

9、 Hydraulic Fluids, and Lubricants usinga Rotational ViscometerD5621 Test Method for Sonic Shear Stability of Hydraulic FluidsD7042 Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer (and the Calculation of KinematicViscosity)E29 Practice for Using Significant Digits in

10、Test Data to Determine Conformance with SpecificationsE1953 Practice for Description of Thermal Analysis and Rheology Apparatus2.2 Society of Automotive Engineers (SAE) Standards:3J300 Engine Oil Viscosity ClassificationJ306 Axle and Manual Transmission Lubricant Viscosity Classification3. Terminolo

11、gy3.1 Definitions:3.1.1 hydraulic fluid, na liquid used in hydraulic systems for lubrication and transmission of power.3.1.2 kinematic viscosity, nthe ratio of the dynamic viscosity to the density of a liquid.1 This practice is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liqu

12、id Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.N0 on Hydraulic Fluids.Current edition approved June 1, 2018Oct. 1, 2018. Published July 2018October 2018. Originally approved in 1997. Last previous edition approved in 20122018 asD6080 12a.D6080 18. DOI: 10.1520/D6080-18.

13、10.1520/D6080-18A.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from SAE International (SAE), 4

14、00 Commonwealth Dr., Warrendale, PA 15096, http:/www.sae.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all cha

15、nges accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Ba

16、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2.1 DiscussionFor gravity flow under a given hydrostatic head, the pressure head of a liquid is proportional to its density. Therefore, kinematicviscosity is a measure of the resistance to flow of a liquid under gravit

17、y.3.1.3 Newtonian oil or fluid, nan oil or fluid that at a given temperature exhibits a constant viscosity at all shear rates or shearstresses.3.1.4 non-Newtonian oil or fluid, nan oil or fluid that at a given temperature exhibits a viscosity that varies with changingshear stress or shear rate.3.1.5

18、 shear degradation, nthe decrease in molecular weight of a polymeric thickener (VI improver) as a result of exposureto high shear stress.3.1.6 shear rate, nthe velocity gradient in fluid flow.3.1.7 shear stability, nthe resistance of a polymer-thickened fluid to shear degradation.3.1.8 shear stress,

19、 nthe motivating force per unit area for fluid flow.3.1.9 viscosity, nthe ratio between the applied shear stress and the rate of shear.3.1.9.1 DiscussionViscosity is sometimes called the coefficient of dynamic viscosity. This coefficient is a measure of the resistance to flow of theliquid.3.1.10 vis

20、cosity index (VI), nan arbitrary number used to characterize the variation of the kinematic viscosity of a fluid withtemperature.3.2 Definitions of Terms Specific to This Standard:3.2.1 in-service viscosity, nthe viscosity of fluid during operation of a hydraulic pump or circuit components.4. Summar

21、y of Practice4.1 High VI hydraulic fluids often contain high molecular weight thickeners, called viscosity index (VI) improvers, whichimpart non-Newtonian characteristics to the fluid. These polymers may shear degrade with use, and reduce the in-service viscosityof the fluids.4.2 This practice provi

22、des uniform guidelines for characterizing oils in terms of both their high and low temperature viscositiesbefore and after exposure to high shear stress.4.2.1 Since the performance of fluids at temperatures higher than 40 C is determined in the worst case, that is, most severesituation, by the shear

23、ed oil viscosity, the viscosity and viscosity index used to characterize fluids in this practice are those of thesheared fluid.4.2.2 This practice classifies oils at low temperature by their new oil properties. Low temperature viscosities do not decreasegreatly, if at all, with polymer shear degrada

24、tion. Furthermore, this approach ensures that the fluid will be properly classified underthe worst-case conditions, that is, when the fluid is new.4.3 This practice may be used with either Newtonian or non-Newtonian hydraulic fluids. This provides the user with a morereasonable basis to compare flui

25、ds than previous practices.5. Significance and Use5.1 The purpose of this practice is to establish viscosity designations derived from viscosities measured by test methods whichhave a meaningful relationship to hydraulic fluid performance. This permits lubricant suppliers, lubricant users, and equip

26、mentdesigners to have a uniform and common basis for designating, specifying, or selecting the viscosity characteristics of hydraulicfluids.5.2 This practice is not intended to be a replacement for Classification D2422. Rather, it is an enhancement intended to providea better description of the visc

27、osity characteristics of lubricants used as hydraulic fluids.5.3 This practice implies no evaluation of hydraulic oil quality other than its viscosity and shear stability under the conditionsspecified.5.4 While it is not intended for other functional fluids, this practice may be useful in high-shear

28、-stress applications whereviscosity index (VI) improvers are used to extend the useful operating temperature range of the fluid.5.5 This practice does not apply to other lubricants for which viscosity classification systems already exist, for example, SAEJ300 for automotive engine oils and SAE J306

29、for axle and manual transmission lubricants.D6080 18a26. Procedure6.1 The low temperature viscosity grade of a fluid is based on the viscosity of new oil measured using a rotational viscometer(see Practice E1953), Test Method D2983.6.1.1 The viscosity shall be interpolated from measurements at three

30、 temperatures spanning the temperature at which theviscosity is 750 mPas. A smooth graph of these data (log viscosity versus temperature) determines the temperature at which theoil has a viscosity of 750 mPas.6.1.2 The temperature determined in 6.1.1 shall be rounded to a whole number in accordance

31、with Practice E29.6.1.3 The low temperature viscosity grade is determined by matching the temperature determined in 6.1.2 with the requirementsshown in Table 1.6.2 The high temperature viscosity designation of a fluid is the 40 C kinematic viscosity (Test MethodMethods D445 orD7042) of a fluid which

32、 has been sheared using Test Method D5621.6.2.1 The kinematic viscosity determined in 6.2 shall be rounded to a whole number in accordance with Practice E29.6.2.2 For a fluid known to contain no polymeric components which will shear degrade, the high temperature viscositydesignation is the 40 C kine

33、matic viscosity (Test MethodMethods D445 or D7042) (see Note 2) of the new fluid, rounded per6.2.1.TABLE 1 Low Temperature Viscosity Grades for Hydraulic FluidClassificationsViscosity GradeTemperature, C, for Rotational Viscosityof 750 mPasAmin maxL5 . 50L7 49 42L10 41 33L15 32 23L22 22 15L32 14 8L4

34、6 7 2L68 1 4L100 5 10L150 11 16A The 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 of100, that is, the temperature range for the L10 grade is approximately the same asthat for an ISO VG 10 grad

35、e with a viscosity index of 100.D6080 18a3NOTE 2Test Method D7042 results shall be bias-corrected by the correction for formulated oils. D445 is the referee method.6.2.3 If the 40 C kinematic viscosity from 6.2.1 fails to meet the same designation consistently (for example, it varies becauseof sprea

36、d in base stock or component specifications, or variability in kinematic viscosity or shear stability measurements), thelower designation must be used to ensure conformance with 6.5 below.6.3 The viscosity index designation of the fluid is based on the viscosity index as determined using Practice D2

37、270 on fluidwhich has been sheared using Test Method D5621.6.3.1 The viscosity index determined in 6.3 shall be rounded to the nearest ten units in accordance with Practice E29. This valueis the viscosity index designation.6.3.2 For fluids which do not contain polymeric components, the viscosity ind

38、ex is determined on the new fluid using PracticeD2270. The viscosity index designation for the fluid is established by rounding this viscosity index to the nearest ten units inaccordance with Practice E29.NOTE 3The guidelines for rounding viscosity in 6.2.1 and 6.2.2 and viscosity index in 6.3.1 and

39、 6.3.2 are specific to this practice and should not beconfused with the larger number of significant figures that can be reported when Test Methods D445, D2270and, D2270and D7042 are used for otherpurposes.6.3.3 If the viscosity index fails to meet the same designation consistently, that is, it vari

40、es between the lower values for onedesignation and the higher values for the next lower designation (for example, it varies because of spread in base stock orcomponent specifications, or variability in kinematic viscosity or shear stability measurements), the lower designation must be usedto ensure

41、conformance with 6.5 below.6.4 For the sake of uniformity of nomenclature in identifying the viscosity characteristics of hydraulic fluids, the followingdesignation shall be used:ISO VG xxLyy-zz (VI)where xx is the new oil viscosity grade as determined by Classification D2422 (Table 2); Lyy is the l

42、ow temperature viscositygrade as determined in 6.1; zz is the high temperature sheared viscosity designation as determined in 6.2; and VI is the viscosityindex designation as determined in 6.3.6.4.1 If the new oil viscosity does not meet a grade described by Classification D2422, the ISO VG xx porti

43、on of the designationdoes not apply. In such cases, the Lyy-zz (VI) designation may still be used, and the use of any other descriptors for the new oilis at the discretion of the fluid marketer.6.4.2 Examples of use of this practice are shown in Table 3.6.5 An oil blender may use any manufacturing c

44、ontrol that seems appropriate to his operation. However, it is the responsibilityof the blender to ensure that all production fully meets the requirements for the viscosity designation on the container.7. Interpretation of Results7.1 The designation determined for a hydraulic fluid as described in 6

45、.4 may be used in combination with a manufacturersviscosity recommendations for specific equipment to estimate an acceptable temperature range over which that fluid may be usedin that equipment.7.2 The low temperature grade determined in 6.1, Lyy, defines the lowest recommended fluid temperature at

46、which the fluid maybe used in equipment with a start-up, under load limit of 750 mPas, max.7.2.1 The low temperature limit is determined by comparing the Lyy designation with the corresponding temperature in Table1.7.2.2 Example 1aFor an oil with the designation:ISO VG 46L32-40 ,TABLE 2 ISO Viscosit

47、y System for Hydraulic FluidsViscosity GradeIdentificationMid-PointViscosity,mm 2/s at 40 CKinematic Viscosity Limits,mm2/s at 40 Cmin maxISO 5 4.6 4.14 5.06ISO 7 6.8 6.12 7.48ISO 10 10 9.00 11.0ISO 15 15 13.5 16.5ISO 22 22 19.8 24.2ISO 32 32 28.8 35.2ISO 46 46 41.4 50.6ISO 68 68 61.2 74.8ISO 100 10

48、0 90.0 110ISO 150 150 135 165D6080 18a4the low temperature grade is defined by L32. Reference to Table 1 indicates that this oil has a viscosity of 750 mPas at atemperature between 8 C and 14 C. Hence, in equipment which has a low temperature start-up viscosity limit of 750 mPas,the oil in this exam

49、ple may be used down to at least 8 C.7.2.3 Example 2aFor an oil with the designation:ISO VG 68L46-57the low temperature grade is defined by L46. Reference to Table 1 indicates that this oil has a viscosity of 750 mPas at atemperature between 2 C and 7 C. Hence, in equipment which has a low temperature start-up viscosity limit of 750 mPas, theoil in this example may be used down to at least 2 C.7.2.4 This practice is not quantitative when a manufacturer specifies lower or higher start-up viscosity limits.