ASTM_G_204_-_15.pdf

Designation:G20415Standard Test Method forDamage to Contacting Solid Surfaces under FrettingConditions1This standard is issued under the fixed designation G204;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.INTRODUCTIONFretting is small amplitude oscillating motion usually in the range of 10 to 300 m.Contacting solidsurfaces subjected to this type of motion can develop significant damage in the form of mass loss,pitting,debris generation,etc.Frequently,pitting damage caused by fretting creates stress concentra-tions that contribute to mechanical failures.Most material couples are susceptible to fretting damageand this test method is intended to assess a tribocouples relative susceptibility to damage underfretting conditions.When tribocouples experience oscillating relative motion less than about 10 m,gross slip(allpoints in a contact experience relative slip over a complete cycle)may not occur.The elastic behaviorof the real contacts may accommodate this motion and fretting damage may not occur.When metal couples are subjected to fretting motion,there is a potential for chemical reaction withthe ambient environment to be a component of the damage.In metals rubbing in air,oxidation offreshly fractured surfaces can occur.When chemical reaction is conjoint with the mechanical damageproduced by fretting,it is called fretting corrosion.When most plastic couples are damaged by frettingmotion,the fractured surfaces may not react with the environment and fretting wear occurs as opposedto fretting corrosion.1.Scope1.1 This test method covers the studying or ranking thesusceptibility of candidate materials to fretting corrosion orfretting wear for the purposes of material selection for appli-cations where fretting corrosion or fretting wear can limitserviceability.1.2 This test method uses a tribological bench test apparatuswith a mechanism or device that will produce the necessaryrelative motion between a contacting hemispherical rider and aflat counterface.The rider is pressed against the flat counter-face with a loading mass.The test method is intended for usein room temperature air,but future editions could includefretting in the presence of lubricants or other environments.1.3 The purpose of this test method is to rub two solidsurfaces together under controlled fretting conditions and toquantify the damage to both surfaces in units of volume loss forthe test method.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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:2E177 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 ErosionG99 Test Method for Wear Testing with a Pin-on-DiskApparatusG117 Guide for Calculating and Reporting Measures of1This test method is under the jurisdiction of ASTM Committee G02 on Wearand Erosion and is the direct responsibility of Subcommittee G02.40 on Non-Abrasive Wear.Current edition approved Nov.15,2015.Published December 2015.Originallyapproved in 2010.Last previous edition approved in 2010 as G20410.DOI:10.1520/G020415.2For 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 Precision Using Data from Interlaboratory Wear or Ero-sion TestsG133 Test Method for Linearly Reciprocating Ball-on-FlatSliding Wear3.Terminology3.1 Definitions:3.1.1 fretting,nin tribology,small amplitude oscillatingmotion usually tangential between two solid surfaces incontact.G403.1.2 fretting corrosion,nform of fretting wear in whichcorrosion plays a significant role.G403.1.3 fretting wear,nwear arising as a result of fretting.G403.2 Definitions of Terms Specific to This Standard:3.2.1 coeffcient of variation(COV),ntest standard devia-tion divided by the test mean.3.2.2 counterface,nflat surface that the rider rubs on inthis test.3.2.3 crater,ncounterface damage in a fretting test from ahemispherical or spherical rider characterized by loss ofmaterial in the form of a surface depression.3.2.4 fretting amplitude,nsliding distance between direc-tion reversals(for example,if a dial indicator is used to