ASTM_D_5763_-_11_2016.pdf

Designation:D576311(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,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 extreme pressure and non-extreme pres-sure gear oils and includes the quantitative determination oftotal sludge,viscosity change,and oil loss.NOTE1While the round-robin tests used ISO VG 220 extremepressure gear oils for developing precision data,the test method can beextended to other viscosity grades 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,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 Transparentand 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 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 the 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-extreme 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 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 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 adhering 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 theamount 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 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 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 States1 5.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 oxidation 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