1、Designation: D4742 081D4742 16Standard Test Method forOxidation Stability of Gasoline Automotive Engine Oils byThin-Film Oxygen Uptake (TFOUT)1This standard is issued under the fixed designation D4742; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1 NOTEUpdated units statement in 1.3 and improved figure quality editorially in November 2009.1. Sc
3、ope*1.1 This test method evaluates the oxidation stability of engine oils for gasoline automotive engines. This test, run at160C,160 C, utilizes a high pressure reactor pressurized with oxygen along with a metal catalyst package, a fuel catalyst, andwater in a partial simulation of the conditions to
4、 which an oil may be subjected in a gasoline combustion engine. This test methodcan be used for engine oils with viscosity in the range from 4 mm4 mm2/s (cSt) to 21 mm21 mm2/s (cSt) at 100C,100 C,including re-refined oils.1.2 This test method is not a substitute for the engine testing of an engine o
5、il in established engine tests, such as Sequence IIID.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3.1 ExceptionPressure units are provided in psig, and dimensions are provided in inches in Annex A1, because these are
6、the industry accepted standard and the apparatus is built according to the figures shown.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practice
7、s and determine the applicability of regulatorylimitations prior to use. For specific warning statements, see Sections 7 and 8.2. Referenced Documents2.1 ASTM Standards:2A314 Specification for Stainless Steel Billets and Bars for ForgingB211 Specification for Aluminum and Aluminum-Alloy Rolled or Co
8、ld Finished Bar, Rod, and WireD664 Test Method for Acid Number of Petroleum Products by Potentiometric TitrationD1193 Specification for Reagent WaterD2272 Test Method for Oxidation Stability of Steam Turbine Oils by Rotating Pressure VesselD4057 Practice for Manual Sampling of Petroleum and Petroleu
9、m ProductsE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 break pointthe precise point of time at which rapid oxidation of the oil begins.3.1.2 oxidation induction timethe time until the oil begins to oxidize at a relativel
10、y rapid rate as indicated by the decrease ofoxygen pressure.3.1.3 oxygen uptakeoxygen absorbed by oil as a result of oil oxidation.4. Summary of Test Method4.1 The test oil is mixed in a glass container with three other liquids that are used to simulate engine conditions: (1) anoxidized/nitrated fue
11、l component (Annex A2), (2) a mixture of soluble metal naphthenates (lead, copper, iron, manganese, and tinnaphthenates (Annex A3), and (3) Type I reagent water.1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct res
12、ponsibility of SubcommitteeD02.09.0G on Oxidation Testing of Engine Oils.Current edition approved Oct. 15, 2008June 1, 2016. Published November 2008June 2016. Originally approved in 1988. Last previous edition approved in 20022008 asD4742D4742 08102a DOI: 10.1520/D4742-08E01.10.1520/D4742-16.2 For r
13、eferencedASTM 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.This document is not an ASTM standard and is intended only to provid
14、e 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 changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the st
15、andard 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 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2 The glass container holding the oil mixture is
16、placed in a high pressure reactor equipped with a pressure gauge. The highpressure reactor is sealed, charged with oxygen to a pressure of 620 kPa (90 psig), 620 kPa (90 psig), and placed in an oil or drybath at 160C160 C at an angle of 30 from the horizontal. The high pressure reactor is rotated ax
17、ially at a speed of 100100 rr/min min forming a thin film of oil within the glass container resulting in a relatively large oil-oxygen contact area.NOTE 1A pressure sensing device can be used in place of a pressure gauge.4.3 The pressure of the high pressure reactor is recorded continuously from the
18、 beginning of the test and the test is terminatedwhen a rapid decrease of the high pressure reactor pressure is observed (Point B, Fig. A1.2). The period of time that elapsesbetween the time when the high pressure reactor is placed in the oil or dry bath and the time at which the pressure begins tod
19、ecrease rapidly is called the oxidation induction time and is used as a measure of the relative oil oxidation stability.5. Significance and Use5.1 This test method is used to evaluate oxidation stability of lubricating base oils with additives in the presence of chemistriessimilar to those found in
20、gasoline engine service. Test results on some ASTM reference oils have been found to correlate withsequence IIID engine test results in hours for a 375 % viscosity increase.3 The test does not constitute a substitute for enginetesting, which measures wear, oxidation stability, volatility, and deposi
21、t control characteristics of lubricants. Properly interpreted,the test may provide input on the oxidation stability of lubricants under simulated engine chemistry.5.2 This test method is intended to be used as a bench screening test and quality control tool for lubricating base oilmanufacturing, esp
22、ecially for re-refined lubricating base oils. This test method is useful for quality control of oxidation stabilityof re-refined oils from batch to batch.5.3 This test method is useful for screening formulated oils prior to engine tests. Within similar additive chemistry and base oiltypes, the ranki
23、ng of oils in this test appears to be predictive of ranking in engine tests. When oils having completely differentadditive chemistry or base oil type are compared, oxidation stability results may not reflect the actual engine test result.3 Ku, C. S. and Hsu, S. M., “A Thin Film Uptake Test for the E
24、valuation of Automotive Lubricants,” Lubrication Engineering , 40, 2, 1984, pp. 7583.FIG. 1 Schematic Drawing of Oxidation Test ApparatusD4742 1625.4 Other oxidation stability test methods have demonstrated that soluble metal catalyst supplies are very inconsistent and theyhave significant effects o
25、n the test results. Thus, for test comparisons, the same source and same batch of metal naphthenates shallbe used.NOTE 2It is also recommended as a good research practice not to use different batches of the fuel component in test comparisons.6. Apparatus6.1 High Pressure Reactor, glass sample contai
26、ner, aluminum insert, pressure gauge, thermometer, test bath and accessories areshown in Figs. 2-3Fig. 2 and Fig. 3, and described in Annex A1.FIG. 2 Pressure versus Time Diagram of the Oxidation TestD4742 163NOTE 3It is reported in literature3 that the oxidation high pressure reactor can be modifie
27、d from the Test Method D2272 oxidation high pressurereactor by insertion of an aluminum cylinder.6.2 Precision Pressure GaugeA certified precision pressure gauge is used to accurately control the oxygen feed to the highpressure reactor. The gauge has a sufficient range to encompass 00 kPa to 650 kPa
28、 650 kPa or more (; 90 psig) (;90 psig)required by the test method with division 2.0 kPa (; 0.5 psig) 2.0 kPa (;0.5 psig) or better to enable readings to be made to 2.0kPa (; 0.25 psig).2.0 kPa (;0.25 psig).7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless o
29、therwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society.47.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean distilled water meetingrequirements of reag
30、ent water as defined by Type I of Specification D1193.7.3 Acetone, CH3COCH3. (WarningExtremely flammable. Irritating to skin, eyes, and mucous membranes.)7.4 Air, containing 2000 ppm 2000 ppm nitrogen dioxide, NO2 (commercially available compressed gas mixture, certifiedwithin 65 %). (WarningNitroge
31、n dioxide is poisonous.)7.5 Hexane, C6H14, Practical Grade or other suitable hydrocarbon solvent. (WarningExtremely flammable. Harmful ifinhaled. May produce nerve cell damage. Skin irritant on repeated contact. Aspiration hazard.)4 Reagent Chemicals, American Chemical Society Specifications, Americ
32、an Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USP
33、C), Rockville, MD.FIG. 3 Schematic Drawing of an Assembled Vessel, Aluminum Insert, and Glass Sample ContainerD4742 1647.6 Isopropyl Alcohol, CH3CH(CH3)OH. (WarningFlammable. Eye irritant. Vapors narcotic.)7.7 Oxygen. (WarningOxygen vigorously accelerates combustion.)7.8 Potassium Hydroxide, Alcohol
34、 Solution (1.5 %)Dissolve 12 g 12 g of potassium hydroxide (KOH) pellets in 1 L of 99 %isopropyl alcohol. (WarningPotassium hydroxide is corrosive.)8. Materials8.1 Fuel ComponentThe fuel component is an oxidized nitrated gasoline fraction. This component may be prepared inaccordance with the procedu
35、res described in Annex A2. (See 8.2 and Note 4.) (WarningFuel component is extremelyflammable. Vapors harmful if inhaled. Skin irritant on repeated contact. Aspiration hazard.)8.2 Soluble Metal Catalyst MixtureThis catalyst5,6 is a mixture of soluble metal catalysts (lead, copper, iron, manganese, a
36、ndtin). The catalyst may be prepared according to the procedures described in Annex A3. (See 8.2 and Note 4.) (WarningLeadand manganese naphthenates are known to be poisonous, but all naphthenates should be handled with care. Naphthenates are alsoflammable.)NOTE 4With some catalyst chemicals, reacti
37、vity can be a problem. This can be curtailed by storing in a refrigerator at approximately 5C.5 C. Thecatalyst chemicals remain effective up to six months after the septum is punctured if they are stored as noted above.NOTE 5It is recommended that each new batch of fuel or metal catalyst be correlat
38、ed with a standard reference oil, in accordance with good laboratorypractices.8.3 Liquid Detergent (Industrial Strength).8.4 Silicone Stopcock Grease.9. Preparation of Apparatus9.1 Glass Sample ContainerRinse the glass sample container with hexane or other suitable hydrocarbon solvent. Clean theglas
39、s container with hot detergent solution and water. Rinse the container with acetone. Blow the container dry with cleancompressed air.NOTE 6A clean glass sample container is important for obtaining repeatable results. Thorough cleaning of the glass sample can be accomplished by(1) hexane rinse, (2) a
40、cetone soak for 15 min, (3) hot detergent solution and water soak for 4 h, 4 h, (4) acetone rinse, and (5) hexane rinse.Aclean glasssample container is important for obtaining repeatable results.NOTE 7A segmented glass sample container has been found suitable to prevent premature mixing of the catal
41、yst components.9.2 Cleaning of High Pressure ReactorWash the inside of the high pressure reactor, aluminum insert, lid, and inside with hotdetergent solution and water. Rinse the inside of the stem with isopropyl alcohol and blow dry with clean compressed air. If thehigh pressure reactor, insert, li
42、d, or inside of the stem emits acidic odor after simple cleaning, wash with 1.5 % a solution ofalcoholic potassium hydroxide (KOH) solution, of 1.5 %, and repeat the cleaning procedures. For dry baths, refer to manufacturersmanuals for details.9.3 Cleaning of High Pressure Reactor StemIt is recommen
43、ded to periodically disassemble, inspect, and clean the highpressure reactor stem. Rinse the inside of the stem with isopropyl alcohol and blow dry with clean compressed air.After cleansing,it is recommended to insert a dry pipe cleaner into the transducer line opening for removal of potential resid
44、ue buildup.NOTE 8It is recommended to replace the O-rings when reassembling the pressure transducers.9.4 To obtain a representative sample of stocks of uniform petroleum products, follow Practice D4057.9.5 Cleaning of Catalyst SyringesIndividual catalyst syringes are to be used for each catalyst com
45、ponent. They are to bethoroughly cleaned and dried prior to each use. (See Annex A4 for recommended procedure.)10. Procedure10.1 Weighing and Mixing Sample and Catalyst Components:10.1.1 Weigh the clean glass sample container to the nearest mg.10.1.2 Weigh 1.5001.500 g 6 0.001 g 0.001 g of oil sampl
46、e into the container.10.1.3 Add 0.0600.060 g 6 0.001 g 0.001 g each of both the fuel component and the soluble metal catalyst mixture.10.1.4 Add 0.0300.030 g 6 0.001 g 0.001 g of distilled water (Type I) to the glass sample container.10.1.5 Just prior to inserting the glass sample container into the
47、 high pressure reactor, thoroughly mix the catalyst componentswithin the sample container by hand-rotation (approximately five rotations) and proceed immediately to 10.2. Delay may resultin variation of results.5 The sole source of supply of the catalyst known to the committee at this time is Tannas
48、 Co., 4800 James Savage Rd., Midland, MI 48642.6 If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1 which you may attend.D4742 16510.2 Hig
49、h Pressure Reactor Charging and AssemblyImmediately and rapidly assemble the high pressure reactor as shown inFig. 1 and Fig. 2. Refer to manufacturers manual for details.10.2.1 Put the aluminum insert into the high pressure reactor followed by the glass sample container and the TFE(tetra-fluoroethylene) plastic cover disk.10.2.2 Place the stainless hold-down spring on top of the TFE disk and the glass sample container.NOTE 9The stainless steel hold-down spring not only holds down the TFE cover disk but, more importantly, pr
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