1、Designation: D5621 07 (Reapproved 2013)Standard Test Method forSonic Shear Stability of Hydraulic Fluids1This standard is issued under the fixed designation D5621; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. 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 test method covers the evaluation of the shearstability of hydraulic fluids in terms of the final viscosity thatresults
3、from irradiating a sample of the hydraulic fluid in asonic oscillator.1.2 Evidence has been presented that a good correlationexists between the shear degradation that results from sonicoscillation and that obtained in a vane pump test procedure.21.3 This test method uses millimetres squared per seco
4、nd(mm2/s), an SI unit, as the unit of viscosity. For information,the equivalent unit, cSt, is shown in parentheses.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate
5、safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D2603 Test Method for Sonic Shear Stability
6、of Polymer-Containing OilsD6022 Practice for Calculation of Permanent Shear StabilityIndex3. Summary of Test Method3.1 A convenient volume of hydraulic fluid is irradiated in asonic oscillator for a period of time and the viscosities beforeand after irradiation are determined by Test Method D445.Ast
7、andard reference fluid containing a readily sheared polymer isrun frequently to ensure that the equipment imparts a con-trolled amount of sonic energy to the sample.3.2 The conditions to obtain the data for the precisionstatement were: 30 mL sample, 12.5 min calibration, and 40min sample irradiation
8、 at 0C jacket temperature.4. Significance and Use4.1 This test method was developed using Test MethodD260391.4.2 This test method permits the evaluation of shear stabilitywith minimum interference from thermal and oxidative factorsthat may be present in some applications. It has been foundapplicable
9、 to fluids containing both readily sheared and shear-resistant polymers. Correlation with performance in the case ofhydraulic applications has been established.5. Apparatus5.1 Sonic Shear Unit, fixed frequency oscillator and sonichorn.5.2 Auxiliary EquipmentTo facilitate uniformperformance, the foll
10、owing auxiliary equipment is recom-mended:5.2.1 Cooling Bath or Ice Bath, to maintain a jackettemperature of 0C.5.2.2 Griffn 50mL Beaker, borosilicate glass.5.2.3 Sonic-Insulated Box, to enclose the sonic horn toreduce the ambient noise level produced by the sonic shearunit.5.3 Viscometer, any visco
11、meter and bath meeting the re-quirements of Test Method D445.6. Reference Fluids6.1 The reference fluid is ASTM Reference Fluid B,4apetroleum oil containing a polymer capable of being brokendown by turbulence at high rates of shear. This oil has a1This test method is under the jurisdiction of ASTM C
12、ommittee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.07 on Flow Properties.Current edition approved Oct. 1, 2013. Published October 2013. Originallyapproved in 1994. Last previous edition approved in 2007 as D5621 07. DOI:10.1520/D5621-0
13、7R13.2Stambaugh, R. L., Kopko, R. J., and Roland, T. F., “Hydraulic PumpPerformanceA Basis for Fluid Viscosity Classification”, SAE Paper No. 901633.Available from Society of Automotive Engineers, 400 Commonwealth Dr.,Warrendale, PA 15096.3For referenced ASTM standards, visit the ASTM website, www.a
14、stm.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.4The sole source of supply of the fluid known to the committee at this time isEvonik Oil Additives USA, 723 Electronic Dri
15、ve, Horsham, PA 190442228. If youare aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.Copyright ASTM International, 100 Barr Har
16、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1viscosity of about 13.6 mm2/s (cSt) at 40C. The viscosity of aspecific lot is supplied by the provider of that lot.7. Calibration of Apparatus7.1 The reference fluid provides a practical way to definethe performance (severity le
17、vel) of a sonic oscillator unit sothat satisfactory comparison can be made between tests run ondifferent days in the same unit and between tests run withdifferent units.7.2 The decrease in viscosity observed for a given hydraulicfluid on irradiation in an oscillator unit depends on a number offactor
18、s; these include sample volume, irradiation time, andoscillator power setting. Frequency of the generator is 23 6 2kHz. Typical power settings are in the range of 50 watts.Manual tuning of the oscillator-horn combination is alsorequired in some instruments in order to ensure efficiency ofenergy coup
19、ling between the two units. The procedure de-scribed in 7.3 is recommended for establishing a reproducibleperformance level for a given unit.7.3 Confirm and record the 40C viscosity of the referencefluid. Introduce 30 mL (room temperature) of the referencefluid into the 50mL Griffin beaker. Immerse
20、the beaker in icewater or a constant temperature bath at 0C until the samplefluid level is below the liquid level in the bath. The beakershould be maintained in a vertical position in the bath. Securebeaker in this position and condition the sample for 12.5 minbefore commencing irradiation. Immerse
21、the sonic horn intothe sample fluid until the tip is at least 10 mm below the surfaceof fluid (see Fig. 1) in order to ensure that the tip remainssubmerged during the test. Exercise care to avoid contact of thetip with the bottom of the beaker as this will shorten tip life.The horn should be placed
22、in a vertical position in the fluid andcentered in the beaker (a weighted ring stand may be used tosupport the horn in this position). True vertical positioning isnot critical and is intended primarily to minimize liquidsplashing during irradiation. Irradiate the fluid for 12.5 min ata preselected p
23、ower setting. Determine the decrease in refer-ence fluid viscosity measured at 40C. Repeat as necessary todetermine the proper power setting to produce a viscositychange at 40C of 15.0 % (61 %). Use this power setting forsubsequent test runs. Daily recalibration of the apparatus isrequired because t
24、he power setting required to produce a statedviscosity loss will probably vary from day to day. Experiencewith a given apparatus set will determine whether morefrequent calibration is required. Calibration in this manner willensure that repeatable severity levels are established.8. Procedure8.1 Clea
25、n the sonic horn using a lintless wiper and optionalsolvent and calibrate the apparatus as described in 7.3. Intro-duce 30 mL of the hydraulic fluid sample to be tested into aclean 50mL Griffin beaker and immerse in the constanttemperature bath at 0C. The beaker should be in a verticalposition. Allo
26、w the sample to equilibrate for 12.5 min. Im-merse the sonic horn in the fluid as described in 7.3. Irradiatethe sample for 40 min at exactly the same power settingdetermined in 7.3. Upon completion of irradiation, remove thesample and clean the sonic horn in preparation for the next run.8.2 Determi
27、ne the viscosity of the sample by Test MethodD445 before and after irradiation.9. Report9.1 Report the initial and irradiated 40C viscosity of thehydraulic fluid.9.2 In addition, the percent viscosity change may be calcu-lated and reported. The percentage loss of viscosity is calcu-lated as follows:
28、Viscosity loss,%5 V02 Vf/V0# 3100 (1)where:V0= viscosity of oil before irradiation, mm2/s (cSt), andVf= viscosity of oil after irradiation, mm2/s (cSt).9.3 The permanent shear stability index (PSSI) may also becalculated and reported in accordance with Practice D6022,provided the base fluid viscosit
29、y is known.FIG. 1 Schematic of Sonic Probe Type Apparatus, SupportSystems, Cabinet, and Power SupplyD5621 07 (2013)210. Precision and Bias510.1 RepeatabilityThe difference between two indepen-dent irradiated viscosity results obtained by the same operatorwith the same apparatus under constant operat
30、ing conditions onidentical test material would, in the long run, in the normal andcorrect operation of the test method, differ from the mean bygreater than 0.38 mm2/s (cSt) in only one case in twenty.10.2 ReproducibilityThe difference between two indepen-dent irradiated viscosity results obtained by
31、 different operatorsworking in different laboratories on identical test materialwould, in the long run, in the normal and correct operation ofthe test method, differ from the mean by greater than 0.60mm2/s (cSt) in only one case in twenty.10.3 BiasThe bias of this test method has not beendetermined
32、because there is insufficient data on the relevantreference (test) standard.10.4 The precision of the percent viscosity loss or thePermanent Shear Stability Index may be estimated using theprecisions of the individual measurements as stated here and inTest Method D445.11. Keywords11.1 hydraulic flui
33、d; shear stability; sonic shear test; viscos-ity stableASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent
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36、ing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard
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