ASTM_D_7420_-_18.pdf

Designation:D742018Standard Test Method forDetermining Tribomechanical Properties of GreaseLubricated Plastic Socket Suspension Joints Using a High-Frequency,Linear-Oscillation(SRV)Test Machine1This standard is issued under the fixed designation D7420;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.INTRODUCTIONThis test method was originally published as bilingual company standard TRW 62 051 301 in June2002.TRW Fahrwerksysteme2transferred the copyright on Oct.5,2004 to standardization bodies.TheDIN 51834 working group has modified this standard by adding precision information based on roundrobin tests.1.Scope*1.1 This test method covers a procedure for determining thefriction and wear behavior of grease lubricated plastic socketsuspension joints,for validation of suspension joint greasesand quality inspection for those greases under high-frequencylinear-oscillation motion using the SRV test machine.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3A295 Specification for High-Carbon Anti-Friction BearingSteelD217 Test Methods for Cone Penetration of LubricatingGreaseD4175 Terminology Relating to Petroleum Products,LiquidFuels,and LubricantsD5706 Test Method for Determining Extreme PressureProperties of Lubricating Greases Using a High-Frequency,Linear-Oscillation(SRV)Test MachineE45 Test Methods for Determining the Inclusion Content ofSteelG40 Terminology Relating to Wear and Erosion2.2 DIN Standards:4DIN EN ISO 683-17 Heat-treated steels,alloy steels andfree-cutting steelsPart 17:Ball and roller bearing steels(replaces DIN 17230-1980)DIN EN ISO 13565-2:1998 Geometrical Product Specifica-tions(GPS)Surface texture:Profile methodSurfaceshaving stratified functional propertiesPart 2:Heightcharacterization using the linear material ratio curveDINEN170224:1998 HeattreatmentofferrousmaterialsMethods of heat treatmentPart 4:Nitridingand nitrocarburizing(available in English)3.Terminology3.1 Definitions:3.1.1 break-in,nin tribology,an initial transition processoccurring in newly established wearing contacts,often accom-panied by transients in coefficient of friction or wear rate,or1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.G0 on Lubricating Grease.Current edition approved Dec.1,2018.Published January 2019.Originallyapproved in 2010.Last previous edition approved in 2017 as D7420 17.DOI:10.1520/D742017.2TRW Fahrwerksysteme(Chassis Systems),D-50543,Dsseldorf,Germany.3For 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.4Available from Beuth Verlag GmbH(DIN-DIN Deutsches Institut furNormung e.V.),Burggrafenstrasse 6,10787,Berlin,Germany,http:/www.en.din.de.*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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 both,which are uncharacteristic of the given tribologicalsystems long-term behavior.G403.1.2 coeffcient of friction,or,nin tribology,thedimensionless ratio of the friction force(F)between twobodies to the normal force(N)pressing these bodies together.G403.1.3 lubricant,nany material interposed between twosurfaces that reduces the friction or wear between them.D41753.1.4 lubricating grease,na semi-fluid to solid product ofa dispersion of a thickener in a liquid lubricant.D2173.1.4.1 DiscussionThe dispersion of the thickener forms atwo-phase system and immobilizes the liquid lubricant bysurface tension and other physical forces.Other