ASTM_D_7420_-_11.pdf

Designation:D742011Standard 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 and health practices and determine the applica-bility of regulatory limitations prior to use.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,PetroleumProducts,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 51631:1999 Special-boiling-point spirits-Require-ments and testingDIN EN 10025-1:2005 Hot rolled products of structuralsteels-Part 1:General technical delivery conditionsDIN EN ISO 683-17 Heat-treated steels,alloy steels andfree-cutting steels-Part 17:Ball and roller bearing steels(replaces DIN 17230-1980)DIN EN ISO 13565-2:1998 Geometrical Product Specifica-tions(GPS)-Surface texture:Profile method-Surfaceshaving stratified functional properties-Part 2:Heightcharacterization using the linear material ratio curve3.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,orboth,which are uncharacteristic of the given tribologicalsystems long-term behavior.G401This 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.1,2011.Published March 2012.Originallyapproved in 2010.Last previous edition approved in 2010 as D742010.DOI:10.1520/D742011.2TRW 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 States1 3.1.2 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 semifluid 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 ingredients arecommonly included to impart special properties.3.1.5 nitro-carburization,nnitro-carburizing is not de-fined in the ASTM Dictionary of Engineering Science andTechnology,but is defined in DIN EN 10025-1:2005.3.1.6 Ra(C.L.A.),nin measuring surface finish,the arith-metic average of the absolute distances of all profile pointsfrom the mean line for a given distance.Amstutz53.1.7 Rpk,nReduced peak height according to DIN ENISO 13565-2:1998.Rpk is the mean height of the peak stickingout above the core profile section.3.1.8 Rvk,nReduced valley height according to DIN ENISO 13565-2:1998.Rvk is t