1、Designation: D5763 11 (Reapproved 2016)Standard Test Method forOxidation and Thermal Stability Characteristics of Gear OilsUsing Universal Glassware1This standard is issued under the fixed designation D5763; the number immediately following the designation indicates the year oforiginal adoption or,
2、in the 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. Scope1.1 This test method covers the determination of the oxida-tion characteristics of ex
3、treme pressure and non-extreme pres-sure gear oils and includes the quantitative determination oftotal sludge, viscosity change, and oil loss.NOTE 1While the round-robin tests used ISO VG 220 extremepressure gear oils for developing precision data, the test method can beextended to other viscosity g
4、rades and to non-extreme pressure gear oils.Refer to Classification D2422 for viscosity grades.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any,
5、associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transpare
6、ntand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D2422 Classification of Industrial Fluid Lubricants by Vis-cosity SystemD2893 Test Methods for Oxidation Characteristics ofExtreme-Pressure Lubrication OilsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4871 Guide for
7、 Universal Oxidation/Thermal StabilityTest Apparatus3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 adherent sludge, nsludge that is formed on the wallsof a container and is not easily removed.3.1.2 aliquot, nportion of sample being tested that is arepresentative portion of th
8、e whole.3.1.3 extreme pressure gear oil, ngear oil that containschemical additives, such as sulfur and phosphorus compounds,which produce a protective film on the metal surface to provideanti-scuffing and anti-scoring properties.3.1.4 filterable sludge, nsludge that is formed in the oil.3.1.5 non-ex
9、treme pressure gear oil, n, ngear oil thatcontains no extreme pressure additives.3.1.6 oxidation, nthe process by which oxygen chemicallyreacts with materials.3.1.7 sludge, nin gear oils, a precipitate that sometimesforms as the oil ages or oxidizes.3.1.8 universal glassware, nthe glassware that is
10、de-scribed in the universal oxidation thermal stability test. Referto Guide D4871.4. Summary of Test Method4.1 The viscosity of the gear oil being tested is determined.A 100 g aliquot of the oil in a weighed apparatus is subjectedto a temperature of 120 C for 312 h while dry air is passedthrough the
11、 aliquot at 3 L h.4.2 At the end of the stress period, the aliquot is cooled toroom temperature. The apparatus is reweighed to determine oilloss. Filterable sludge is recovered by vacuum filtration usinga 2.8 m glass fiber filter medium. The viscosity of the filteredoil is determined. Sludge adherin
12、g to the oxidation cell andassociated glassware is rinsed with heptane and the washingspassed through the same filter used to filter the filterablesludge. The filter is dried in an oven to a constant weight todetermine the total filterable sludge.4.3 The apparatus is dried and weighed to determine t
13、heamount of adherent sludge. The sum of the filterable sludge andadherent sludge is reported as total sludge. The percentagechange in viscosity and percent oil loss are also reported.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants
14、and is the direct responsibility ofSubcommittee D02.09.0D on Oxidation of Lubricants.Current edition approved Oct. 1, 2016. Published November 2016. Originallyapproved in 1995. Last previous edition approved in 2011 as D5763 11. DOI:10.1520/D5763-11R16.2For referenced ASTM standards, visit the ASTM
15、website, www.astm.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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United S
16、tates15. Significance and Use5.1 Degradation of gear oils by oxidation or thermalbreakdown, or both, can result in sludge buildup and render theoil unsuitable for further use as a lubricant.5.2 This is the only test method that employs glassware tomeasure the amount of sludge produced during oxidati
17、on andthermal degradation. This test method is a modification of TestMethod D2893 which measures the viscosity increase andprecipitation number of the oil stressed at 95 C, but does notmeasure the amount of sludge formed.5.3 This test method can be used to evaluate the oxidation/thermal stability of
18、 gear oils. However, the test results may notcorrelate with the performance of gear oils in field service.6. Apparatus6.1 Heating Bath or Block,3thermostatically controlled, ca-pable of maintaining the oil sample in the oxidation cell at auniform temperature of 120 C 6 1 C and large enough tohold a
19、minimum of two oxidation cells and sufficiently deep toallow approximately 120 mm of the test tubes to extend abovethe heating liquid or block. The heating block is furtherdescribed in Test Method D4871.6.2 Oxidation Cell,3consists of borosilicate glass; a 38 mminside diameter and a 300 mm 6 5 mm le
20、ngth is required.NOTE 2While the round-robin test used the oxidation cell from aspecific equipment manufacturer in determining the precision statement,the test method permits the use of other oxidation cells that meet therequirements of 6.2.6.3 Air Delivery Tube,3a borosilicate glass tube having ani
21、nside diameter of 5 mm and a minimum length of 320 mm,with the lower tip cut at a 45 angle.NOTE 3The oxidation cell and delivery tube are further described inTest Method D4871.6.4 Flowmeters,3one for each oxidation cell, capable ofmeasuring an air flow of 3 L h 6 0.5 L h.6.5 Air DryerBefore being su
22、pplied to the flowmeters, theair shall be passed through a drying tower packed withindicating grade anhydrous calcium sulfate or equivalent. Thequantity of desiccant should be sufficient to last for the entiretest. It is recommended that the drying tower be filled withfresh desiccant prior to the te
23、st.6.6 Filter, glass fiber, 2.8 m porosity, 47 mm in diameter.6.7 Balance, electronic, top-loading, capable of weighing tothe nearest centigram (0.01 g) and having the capacity to weighup to 2000 g.6.8 Filter Holder, 47 mm, consisting of a borosilicate glassfunnel and a funnel base with a coarse-gra
24、de fritted glass filtersupport or stainless steel screen support such that the filter canbe clamped between the ground glass sealing surfaces of thefunnel and its base by means of a metal clamp.6.9 Oven, explosive-proof, capable of heating from 50 C to60 C and of a sufficient size to hold oxidation
25、cells.6.10 Thermometer, ASTM solvent distillation thermometerhaving a range from 98 C to 152 C or equivalent digitalcontact thermometer.6.11 Vacuum Source, to provide pressure reduction to100 mm 6 5 mm Hg absolute pressure.7. Reagents and Materials7.1 Air Supply, dried air, oil free, at constant pre
26、ssure topermit 3 L h air flow through the system. House air supply orpressurized air cylinders can be used.7.2 Calcium Sulfate Desiccant, Anhydrous, indicating grade(desiccant that changes color when it nears saturation withwater). Desiccants equivalent to calcium sulfate can be used.7.3 Heptanemini
27、mum purity, 99.75 %. (WarningHeptane is flammable and a health hazard.)8. Sampling8.1 Samples for this test method can come from tanks,drums, small containers, or operating equipment. Therefore,use the applicable apparatus and techniques described inPractice D4057 to obtain suitable samples.8.2 Spec
28、ial precautions to preserve the integrity of a samplewill not normally be required. It is good practice to avoidundue exposure of samples to heat, sunlight, or strong directlight. Visibly heterogeneous samples should not be used.8.3 It is recommended that a 200 mL representative beobtained. To ensur
29、e the aliquot being tested is representative ofthe sample, agitation; for example, stirring or shaking of the oilprior to obtaining an aliquot, is recommended.9. Preparation of Apparatus9.1 Cleaning Glassware:9.1.1 Clean new glassware by washing with a hot detergentsolution (using a bristle brush) a
30、nd rinse thoroughly with tapwater. When any visible deposits remain, soaking with a hotdetergent solution can be helpful. After final cleaning bysoaking with a suitable cleaning solution rinse thoroughly withtap water and then distilled water, and allow to dry at roomtemperature or in an oven.9.1.2
31、Used glassware should be cleaned immediately fol-lowing the end of a test. When additional cleaning is necessary,use a non-chromic acid containing cleaning solution.9.2 Heating Block or BathEnsure that the heating block orbath is able to heat the oxidation cell at the control temperatureof 120 C.9.3
32、 FlowmeterEnsure that the flowmeter is capable ofdelivering the desired flow rate of 3.0 L of air per hour.10. Procedure10.1 Using Test Method D445, determine the viscosity ofthe oil at 100 C. Record as V2.3The sole source of supply of the apparatus (universal glassware and heatingbath with flowmete
33、rs as a complete unit) known to the committee at this time isFalex Corporation, 1020 Airpark Drive, Sugar Grove, IL 60554-9452. If you areaware of alternative suppliers, please provide this information to ASTM Interna-tional Headquarters. Your comments will receive careful consideration at a meeting
34、of the responsible technical committee,1which you may attend.D5763 11 (2016)210.2 Adjust the heating bath or block to a temperature highenough to maintain the oil in the desired number of oxidationcells at the required temperature of 120 C 6 1 C.10.3 Place and weigh a 1000 mL beaker on the balance.Z
35、ero the tare of the beaker and place the oxidation cell in thebeaker. Insert the air delivery tube in the cell. The angled tip ofthe air delivery tube should rest on the bottom of the oxidationcell. Obtain the weight of the cell and delivery tube. Record asB1.10.4 Slowly pour 100.00 g 6 0.1 g of oil
36、 sample into theoxidation cell which contains the air delivery tube. Obtain theweight of the oil sample, air delivery tube, and oxidation cell,A2.10.5 Place the oxidation cell containing the oil sample andair delivery tube in the heating block or bath.10.6 Connect the air delivery tube to the air so
37、urce from theflowmeter. Adjust the flow of dried air to 3 L h 6 0.5 L h.10.7 Monitor the temperature of the oil sample and adjustthe heating block/bath thermostat, if necessary. Observe thetemperature of the oil sample twice during the first hour, thenonce every hour for at least 3 h, making the nec
38、essaryadjustment each time until a constant temperature of 120 C 61 C is read twice in succession. Check the air flow andtemperature at least twice a day and adjust the control flow,when necessary.10.8 At the end of 312 h (13 days), remove the oxidationcell containing the oxidized oil and delivery t
39、ube from the bathor block, and allow the oxidized oil to cool to room tempera-ture. When an oil bath is used, rinse the outside of the oxidationcell with heptane and wipe dry. Place the cell and its contentsin a tared 1000 mL beaker and obtain the weight of the oilsample, oxidation cell, and deliver
40、y tube as in 10.4. Record thisweight, A1.10.9 Weigh a 2.8 m glass fiber filter to the nearest 0.01 gand record, F1. Using the filter holder apparatus, vacuum filterthe cooled oxidized oil through the glass filter. Determine theviscosity at 100 C of the filtered oil by Test Method D445.Record the vis
41、cosity result, V1.NOTE 4The viscosity and sludge determinations for the oxidized oilshould be done within four days after removing the cell from the heatingbath or block. It has been found that extending storage time beyond fourdays can give variable test results.10.10 Wash the oxidation cell and ai
42、r delivery tube withheptane and filter the washings through the same filter. Con-tinue washing until the heptane is no longer colored by theoxidized oil. Draw air through the filter until the precipitateappears dry. Place the filter in an operating hood for 0.5 h toevaporate heptane. Transfer the fi
43、lter to a 50 C to 60 Cexplosive-proof oven for 0.5 h. Let cool to room temperatureand weigh, F2.10.11 Allow heptane to evaporate from the oxidation celland then place the cell in an explosive-proof oven at 50 C to60 C for 1 h to 2 h. Dry the air delivery tube by passing airthrough the tube. Let the
44、oxidation cell cool to room tempera-ture. Weigh the oxidation cell and air delivery tube, B2.11. Calculations11.1 Determine the amount of sludge, viscosity change, andoil loss by the following equations.11.1.1 Filterable sludge on filter, g.D25 F22 F1(1)where:D2= amount of sludge on filter pad, g,F2
45、= weight of filter pad and sludge, g, andF1= weight of filter, g.11.1.2 Adherent sludge on oxidation cell and air deliverytube, g.D15 B22 B1(2)where:D1= amount of sludge on oxidation cell and air deliverytube, g,B2= weight of oxidation cell and air delivery tube, solventwashed and dried, g, andB1= o
46、riginal weight of oxidation cell and air delivery tube,g.11.1.3 Total sludge, g.D35 D11D2(3)where:D3= total amount of sludge, g.11.1.4 Viscosity at 100 C increase, mm2,%V35V12 V2V23100 (4)where:V3= viscosity increase, %,V2= original viscosity of oil sample, andV1= viscosity of oxidized oil sample.11
47、.1.5 Oil loss, g.C35 A22 A1(5)where:C3= oil loss, g,A2= original combined weight of oil sample, oxidation cell,and air delivery tube, g, andA1= combined weight of oxidized oil, oxidation cell, and airdelivery tube, g.12. Report12.1 Report the amount of filterable sludge on the filter tothe nearest 0
48、.01 g.12.2 Report the amount of adherent sludge on the oxidationtubes to the nearest 0.01 g.12.3 Report the total amount of sludge to the nearest 0.01 gor to the nearest 0.01 %.12.4 Report the viscosity increase in percent.12.5 Report oil loss to the nearest 0.01 g or percent.D5763 11 (2016)313. Pre
49、cision and Bias413.1 PrecisionThe precision of this test method as deter-mined by the statistical examination of the interlaboratory testresults is as follows.13.1.1 Total Sludge:13.1.1.1 RepeatabilityThe difference between successiveresults obtained by the same operator with the same apparatusunder constant operating conditions on identical test materialswould in the long run, in the normal and correct operation ofthe test method, exceed the following values only in one casein twenty:Repeatability 5 0.42 =x 5 g %! (6)where:x = fou
