ASTM_G_181_-_11_2017.pdf

Designation:G18111(Reapproved 2017)Standard Test Method forConducting Friction Tests of Piston Ring and Cylinder LinerMaterials Under Lubricated Conditions1This standard is issued under the fixed designation G181;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 procedures for conductinglaboratory bench-scale friction tests of materials,coatings,andsurface treatments intended for use in piston rings and cylinderliners in diesel or spark-ignition engines.The goal of thisprocedure is to provide a means for preliminary,cost-effectivescreening or evaluation of candidate ring and liner materials.Areciprocating sliding arrangement is used to simulate thecontact that occurs between a piston ring and its mating linernear the top-dead-center position in the cylinder where liquidlubrication is least effective,and most wear is known to occur.Special attention is paid to specimen alignment,running-in,and lubricant condition.1.2 This test method does not purport to simulate all aspectsof a fired engines operating environment,but is intended toserve as a means for preliminary screening for assessing thefrictional characteristics of candidate piston ring and linermaterial combinations in the presence of fluids that behave asuse-conditioned engine oils.Therefore,it is beyond the scopeof this test method to describe how one might establishcorrelations between the described test results and the frictionalcharacteristics of rings and cylinder bore materials for specificengine designs or operating conditions.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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.1.5 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:2D6838 Test Method for Cummins M11 High Soot TestE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG40 Terminology Relating to Wear and Erosion3.Terminology3.1 For definitions,see Terminology G40.3.2 Definitions of Terms Specific to This Standard:3.2.1 conditioned oila lubricating oil whose viscosity,composition,and other function-related characteristics havebeen altered by use in an operating engine,such that the oilseffects on friction and wear reflect those characteristic of thelong-term,steady-state engine operation.3.2.2 conformal contactin friction and wear testing,anymacro-geometric specimen configuration in which the curva-ture of one contact surface matches that of the countersurface.3.2.2.1 DiscussionExamples of conformal contact includea flat surface sliding on a flat surface and a ball rotating in asocket that conforms to the shape of the ball.Apair of surfacesmay begin a wear or friction test in a non-conforming contactconfiguration,but develop a conformal contact as a result ofwear.3.2.3 lubrication regimein liquid-lubricated slidingcontact,a certain range of friction coefficients that results froma combination of contact geometry,lubricant viscositycharacteristics,surface roughness,normal pressure,and therelative speed of the bearing surfaces.3.2.3.1 DiscussionCommon designations for lubrication1This test method is under the jurisdiction of ASTM Committee G02 on Wearand Erosion and is the direct responsibility of Subcommittee G02.50 on Friction.Current edition approved June 1,2017.Published June 2017.Originallyapproved in 2004.Last previous edition approved in 2011 as G181 11.DOI:10.1520/G0181-11R17.2For 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 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 regimes are boundary lu