ASTM_F_2730_-_F_2730M_-_14.pdf

Designation:F2730/F2730M14Standard Specification forSilicon Nitride Cylindrical Bearing Rollers1This standard is issued under the fixed designation F2730/F2730M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers the establishment of the basicquality,physical/mechanical property,and test requirementsfor silicon nitride rollers Classes I,II,and III to be used forcylindrical roller bearings.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are not exact equivalents;therefore,each systemmust be used independently of the other.Combining valuesfrom the two systems may result in nonconformance with thespecification.2.Referenced Documents2.1 Order of Precedence:2.1.1 In the event of a conflict between the text of thisdocument and the references herein,the text of this documenttakes precedence.Nothing in this document,however,super-sedes applicable laws and regulations unless a specific exemp-tion has been obtained.2.2 ASTM Standards:2C1161 Test Method for Flexural Strength of AdvancedCeramics at Ambient TemperatureC1421 Test Methods for Determination of Fracture Tough-ness of Advanced Ceramics at Ambient Temperature2.3 ASME Standard:3B 46.1 Surface Texture(Surface Roughness,Waviness,andLay)2.4 JIS Standards:4R 1601 Testing Method for Flexural Strength(Modulus ofRupture)of High Performance CeramicsR 1607 Testing Method for Fracture Toughness of HighPerformance Ceramics2.5 CEN Standards:5EN 843-1 Advanced Technical CeramicsMonolithicCeramicsMechanical Properties at Room Temperature,Part 1,Determination of Flexural StrengthENV 843-5 Advanced Technical CeramicsMonolithicCeramicsMechanical Properties at Room Temperature,Part 5,Statistical Analysis2.6 ISO Standard:6Hardmetals-Metallographic determination of porosity anduncombined carbon3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 ceramic second phase,nsintering additive basedphases,for example yttria and alumina,which appear darker orlighter than the silicon nitride matrix but are not highlyreflective in nature when viewed under reflected light micros-copy and bright field illumination.3.1.2 chips,nbreak-outs of material greater in extent than0.25 mm 0.1 in.typically at the corner chamfers or thejunction of the chamfers with the cylindrical surface or endface.3.1.3 color variation,nan area that appears lighter ordarker than the surrounding area under reflected light micros-copy but with no discernible physical discontinuity associatedwith it.3.1.3.1 DiscussionColor variation is often not visibleunder scanning electron microscopy(SEM)examination.3.1.4 cracks,nirregular,narrow breaks in the surface ofthe roller typically having a visible width of less than 0.002mm.0.00008 in.3.1.4.1 DiscussionMost cracks are formed after densifica-tion but occasionally may be present as material faults.Somecracks may not be visible with normal white light microscopyand may only show up under ultraviolet light after processingwith a suitable fluorescent penetrant.1This specification is under the jurisdiction ofASTM Committee F34 on RollingElement Bearings and is the direct responsibility of Subcommittee F34.01 onRolling Element.Current edition approved March 15,2014.Published March 2014.Originallyapproved in 2008.Last previous edition approved in 2013 as F2708/F2708M13.DOI:10.1520/F2730_F2730M-14.2For 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.3Available from American Society of Mechanical Engineers(ASME),ASMEInternational Headquarters,Three Park Ave.,New York,NY 10016-5990,http:/www.asme.org.4Available from Japanese Standards Organization(JSA),4-1-24 AkasakaMinato-Ku,Tokyo,107-8440,Japan,http:/www.jsa.or.jp.5Available from European Committee for Standardization(CEN),36 rue deStassart,B-1050,Brussels,Belgium,http:/www.cenorm.be.6Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.5 cuts,nshort linear or circumferential grooves havinga width of more than 0.005 mm 0.002 in.and a length ofmore than 0.20 mm 0.008 in.Cuts are normally assessedunder roller surface appearance but large or numerous cuts,orboth can be considered defects.3.1.6 flats,nflat bands running along the length of thecylindrical part of the roller,usually caused by a stop inrotation of the roller during machining.3.1.6.1 DiscussionFlats can also be formed at one endonly by incorrect