1、Designation:D513312D513313 Standard Test Method for Low Temperature, Low Shear Rate, Viscosity/Temperature Dependence of Lubricating Oils Using a Temperature- Scanning Technique 1 This standard is issued under the xed designation D5133; the number immediately following the designation indicates the
2、year of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval. 1. Scope* 1.1 This test method covers the measurement of the app
3、arent viscosity of engine oil at low temperatures. 1.2 A shear rate of approximately 0.2 s -1 is produced at shear stresses below 100 Pa. Apparent viscosity is measured continuously as the sample is cooled at a rate of 1C/h over the range 5 to 40C, or to the temperature at which the viscosity exceed
4、s 40 000 mPas (cP). 1.3 The measurements resulting from this test method are viscosity, the maximum rate of viscosity increase (Gelation Index), and the temperature at which the Gelation Index occurs. 1.4 Applicability to petroleum products other than engine oils has not been determined in preparing
5、 this test method. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this st
6、andard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards: 2 D341Practice for Viscosity-Temperature Charts for Liquid Petroleum Products D3829Test Method for Predicting the Borderline
7、 Pumping Temperature of Engine Oil D4684Test Method for Determination of Yield Stress and Apparent Viscosity of Engine Oils at Low Temperature 3. Terminology 3.1 Denitions: 3.1.1 apparent viscosity, nthe viscosity obtained by use of this test method. 3.1.1.1 Discussion See 3.1.6 for denition of visc
8、osity and units. 3.1.2 Newtonian oil, nan oil that, at a given temperature, exhibits a constant viscosity at all shear rates or shear stresses. 3.1.3 non-Newtonian oil, nan oil that, at a given temperature, exhibits a viscosity that varies with shear stress or shear rate. 3.1.4 shear rate, nvelocity
9、 gradient perpendicular to the direction of ow. 3.1.4.1 Discussion 1 This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee D02.07 on Flow Properties. Current edition approved Dec.
10、 1, 2012Sept. 1, 2013. Published February 2013September 2013. Originally approved in 1990. Last previous edition approved in 20112012 as D513305(2011).D513312. DOI: 10.1520/D5133-12.10.1520/D5133-13. 2 ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservicea
11、stm.org.ForAnnualBookofASTMStandards volume information, refer to the standards Document Summary page on the ASTM website. This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because it
12、 may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version of the standard as published by ASTM is to be considered the official document. *ASummary of Changes section appears a
13、t the end of this standard Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States 1The SI unit for shear rate is the reciprocal second (1/s; also s -1 ). 3.1.5 shear stress, nforce per unit area in the direction of ow. 3.1.5.1 Discussion The
14、 SI unit for shear stress is the Pascal (Pa). 3.1.6 viscosity, nthat property of a uid which resists ow. 3.1.6.1 Discussion Viscosity is dened as the ratio of the applied shear stress (force causing ow) and the shear rate (resultant velocity of ow per unit distance from a stationary surface wet by t
15、he uid). Mathematically expressed: viscosity5shearstress/shearrateor,symbolically,h5t/g (1) viscosity5shearstress/shearrateor,symbolically,h5t/g (1) in which the symbols in the second portion of Eq 1 are dened by the terms in the rst portion of the equation. The SI unit for viscosity used herein is
16、milliPascal seconds (mPas). 3.2 Denitions of Terms Specic to This Standard: 3 3.2.1 air-binding oilsthose engine oils whose borderline pumping temperatures are determined by a combination of gelation and viscous ow. 3.2.2 borderline pumping temperature, nthat temperature at which an engine oil may h
17、ave such poor ow characteristics that the engine oil pump may not be capable of supplying sufficient lubricant to the engine. 3.2.3 calibration oil, nNewtonian oils developed and used to calibrate the viscometer drive module over the viscosity range required for this test method. 3.2.3.1 Discussion
18、these calibration oils are specially blended to give sufficient sensitivity and range for the special viscometer head used. 3.2.4 computer-programmed automated analysis, nuse of modern techniques for acquiring analog data, converting these to digital values and using this information to automaticall
19、y record and analyze torque output from the viscometer drive module and to render this information into tabular data and plotted relationships. 3.2.4.1 analog-to-digital (A-D) converter, na device for converting continuously produced electrical signals into discrete numerical values capable of being
20、 analyzed by computer technology. 3.2.5 critical pumpability temperature, nthe temperature in the viscometer bath at which an oil reaches a chosen critical pumpability viscosity (see 3.2.6). 3.2.6 critical pumpability viscosity, nthat apparent viscosity believed to cause pumpability problems in an e
21、ngine. This apparent viscosity is chosen to test an oil for its critical pumpability temperature. 3.2.7 ow-limited oils, nthose oils whose borderline pumping temperatures are determined by viscous ow. 3.2.8 gelation, na rheological condition of an oil characterized by a marked increase in the ow res
22、istance over and above the normal exponential increase of viscosity with decreasing temperature, particularly at lower shear stresses and temperatures. 3.2.8.1 Discussion Gelation has been attributed to a process of nucleation and crystallization of components of the engine oil and the formation of
23、a structure. 4 3.2.9 Gelation Index, nthe maximum value of the incremental ratio 3 The sole source of supply of the equipment and materials known to the committee at this time is Tannas Co., 4800 James Savage Rd., Midland, MI 48642. If you are aware of alternative suppliers, please provide this info
24、rmation to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, 1 which you may attend. 4 Symposium on Low Temperature Lubricant Rheology Measurement and Relevance to Engine Operation, ASTM STP 1143, Rhodes, R. B., ed.
25、, ASTM, 1992. D513313 22loglogh 1 !2loglogh 2 !#/logT 1 2logT 2 ! (2) (in which h is dynamic viscosity and T is in degrees Kelvin) over the temperature range scanned when the incremental de- crease in temperature is 1 K. 3.2.9.1 Discussion The technique of deriving Gelation Index was rst developed a
26、nd practiced 5 collecting information from a strip-chart recording and applying the empirical MacCoull-Walther-Wright equation (Test Method D341). For further information, see Appendix X1. 3.2.10 Gelation Index reference oils, nnon-Newtonian oils chosen to give certain levels of Gelation Index as a
27、check on instrument performance 3 . 3.2.11 Gelation Index temperature, nthe temperature (t 2 in Eq 2) in degrees Celsius at which the Gelation Index occurs. 3.2.12 pre-treatment sample heating bath, nawaterorairbathtoheatthesamplesfor1.5to2.0hat9062Cbeforetesting. 3.2.13 programmable liquid cold bat
28、h, na liquid or dry block (referred to as direct cooling) bath having a temperature controller capable of being programmed to run the calibration and the analysis portions of the test method.method within the temperature tolerances listed. 3.2.14 temperature controller, na programmable device which,
29、 when properly programmed, ramps the temperature upward or downward at a chosen rate or series of steps while simultaneously controlling temperature excursions. 3.2.14.1 calibration program, na program to run the required series of temperatures at which the torque values necessary to calibrate the v
30、iscometer drive module are collected and analyzed. 3.2.14.2 test program, na program to run the test oil analysis at 1C/h temperature decrease. 3.2.14.3 hold program, na program to reach and hold the programmable liquid cold bath at 5C. 3.2.15 test cell, nthe combination of the rotor and stator. Cri
31、tical elements of the test cell are sketched in Fig. 1. 3.2.15.1 rotor, na titanium rotor sized to give a compromise of sensitivity and range to the determination of viscosity and gelation using this test method. (1) stator, na precision-bore borosilicate glass or stainless steel tube, to which a me
32、asured amount of oil is added for the test and within which the specially-made rotor turns. (2) stator collar, na clamp for the stator which also positions it on the test cell alignment device. 5 Selby, T.W., The Use of the Scanning Brookeld Technique to Study the Critical Degree of Gelation of Lubr
33、icants at Low Temperatures, SAE Paper 910746, Society of Automotive Engineers, 1991. FIG. 1 Test Cell D513313 33.2.16 testcellalignmentdevice 6 ,naspecialdeviceusedtosupporttheviscometerdrivemodulewhilemaintainingthestator and the rotor coaxial and vertical in regard to the viscometer driveshaft. La
34、ter designs permit dry gas into the cell to prevent moisture and frost buildup. 3.2.17 test oil, nany oil for which apparent viscosity is to be determined using the procedure described by this test method. 3.2.18 viscometer drive module, nthe rotor drive and torque-sensing component of a rotational
35、viscometer. 3.2.19 viscometer module support, na part of the test cell alignment device supporting the viscometer drive module. 4. Summary of Test Method 4.1 After pre-heating approximately 20 mLof the test oil in a glass stator at 90C for 1.5 to 2.0 h., the test cell containing the test oil is atta
36、ched to a suitable viscometer drive module and the test cell immersed in a liquid cold bath and cooled at 1C/h over the temperature range of 5 to 40C. Data from the viscometer drive module is collected and fed to a computerized data assimilation program to determine the Gelation Index, Gelation Inde
37、x temperature, and Critical Pumpability temperature for a selected viscosity such as 30 000 or 40 000 mPas (cP). 5. Signicance and Use 5.1 Signicance of Low-Temperature, Low Shear Rate, Engine Oil RheologyThe low-temperature, low-shear viscometric behavior of an engine oil determines whether the oil
38、 will ow to the sump inlet screen, then to the oil pump, then to the sites in the engine requiring lubrication in sufficient quantity to prevent engine damage immediately or ultimately after cold temperature starting. 5.1.1 Two forms of ow problems have been identied, 4 ow-limited and air-binding be
39、havior. The rst form of ow restriction, ow-limited behavior, is associated with the oils viscosity; the second, air-binding behavior, is associated with gelation. 5.2 Signicance of the Test MethodThe temperature-scanning technique employed by this test method was designed to determine the susceptibi
40、lity of the engine oil to ow-limited and air-binding response to slow cooling conditions by providing continuousinformationontherheologicalconditionoftheoiloverthetemperaturerangeofuse. 4 ,5,7 Inthisway,bothviscometric and gelation response are obtained in one test. NOTE 1This test method is one of
41、three related to pumpability related problems. Measurement of low-temperature viscosity by the two other pumpabilityTestMethodsD3829andD4684,holdthesampleinaquiescentstateandgeneratetheapparentviscosityofthesampleatshearratesranging up to 15 sec -1 and shear stresses up to 525 Pa at a previously sel
42、ected temperature. Such difference in test parameters (shear rate, shear stress, sample motion, temperature scanning, and so forth) can lead to differences in the measured apparent viscosity among these test methods with some test oils, particularly when other rheological factors associated with gel
43、ation are present. In addition, the three methods differ considerably in cooling rates. 5.3 Gelation Index and Gelation Index TemperatureThis test method has been further developed to yield parameters called theGelationIndexandGelationIndextemperature.Therstparameterisameasureofthemaximumrateoftorqu
44、eincreasecaused by the rheological response of the oil as the oil is cooled slowly. The second parameter is the temperature at which the Gelation Index occurs. 6. Apparatus 3 6.1 Test Cell, shown in Fig. 1, consisting of a matched rotor and a stator of the following critical dimensions: 6.1.1 Rotor
45、dimensions for: critical length is 65.5 mm (60.1 mm) and critical diameter is 18.40 mm (60.02 mm). 6.1.2 Stator dimensions for: critical diameter is 22.05 mm (60.02 mm) at whatever length will satisfy the immersion depth when the upper oil level is a minimum of 15 mm below the cooling liquid level o
46、ver the entire temperature range. 6.2 Viscometer Drive Modules, rotational viscometer drive modules capable of producing an analog signal to an analog-to- digital converter or other analog signal data processor such as a strip-chart recorder. 6.2.1 With the rotor and stator described in 6.1.1 and 6.
47、1.2, the viscometer drive module shall be capable of measuring to at least 45 000 mPas (cP). 6.3 TestCellAlignmentDevice,simultaneouslymaintainsaverticalaxialalignmentandreasonablyconsistentpositioningofthe rotor in the stator to give repeatable torque readout from test to test when setting up the a
48、pparatus for analysis. 6.3.1 Viscometer Support, supports the viscometer drive module and aligns it vertically. 6.3.2 StatorCollarStatorCollar,clampsthestatorandsupportsitwhenthestatorcollarisattachedtotheviscometersupport. 6.4 Ameansofprovidingadrygasatmosphereoverthetopofthetestsampleisnecessaryto
49、preventcondensationandfreezing of water on the oil surface. 6 The test cell alignment device is covered by patents. Interested parties are invited to submit information regarding the identication of alternatives to this patented item to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. 7 Shaub, H., AHistory ofASTMAccomplishments in Low Temperature Engine Oil Rheology, Sy
