ASTM_A_914_-_A_914M_-_16.pdf

Designation:A914/A914M16Standard Specification forSteel Bars Subject to Restricted End-Quench HardenabilityRequirements1This standard is issued under the fixed designation A914/A914M;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.Scope*1.1 This specification covers hot-worked alloy and carbon-boron steels designed to attain restricted depth of hardening inthe end-quench test.These steel compositions are identified bythe suffix letter“RH”added to the conventional grade number.1.2 In general,steels with restricted hardenability(RHsteels)will exhibit a hardness range not greater than 5 HRC atthe initial position on the end-quench hardenability bar and notgreater than 65%of the hardness range for standard H-bandsteels(Specification A304)in the inflection region.Generallythe restricted hardenability band follows the middle of thecorresponding standard H-band.An example of the RH bandcompared with the H band is given for Grade 4140 in Fig.1.1.2.1 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This specification is expressed in both inch-pound unitsand SI units.However,the material will be supplied toinch-pound units unless the purchase order specifies the“M”specification designation.2.Referenced Documents2.1 ASTM Standards:2A29/A29M Specification for General Requirements for SteelBars,Carbon and Alloy,Hot-WroughtA255 Test Methods for Determining Hardenability of SteelA304 Specification for Carbon and Alloy Steel Bars Subjectto End-Quench Hardenability RequirementsE112 Test Methods for Determining Average Grain Size2.2 SAE Standards:3J 406 Methods of Determining Hardenability of SteelsJ 1268 Hardenability Bands for Carbon and Alloy H SteelsJ 1868 Restricted Hardenability Bands for Selected AlloySteels3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 hardenabilitythe relative ability of a steel to hardenunder heat treatment becomes apparent in the degree to whichthe material hardens when quenched at different cooling rates.3.1.1.1 DiscussionHardenabilityismeasuredquantitatively,usually by noting the extent or depth of hard-ening of a standard size and shape test specimen in astandardized quench.In the end-quench test the depth ofhardening is the distance along the specimen from thequenched end to a given hardness.4.Ordering Information4.1 Orders for material under this specification shouldinclude the following information,in proper sequence:4.1.1 Quantity(weight),4.1.2 Name of material(alloy or carbon-boron steel),4.1.3 Cross-sectional shape,4.1.4 Size,4.1.5 Length,4.1.6 Grade,4.1.7 End-quenched hardenability(see Section 9),4.1.8 Report of heat analysis,if desired(see Section 7),4.1.9 Special straightness,if required,4.1.10 ASTM designation and date of issue,and4.1.11 End use or special requirements.NOTE1A typical ordering description is as follows:10 000 lb,alloybars,round,4.0-in.diameter by 10 ft,Grade 4140RH,heat analysisrequired,complete hardenability data required,ASTMAXXX,AXXXMdated _ worm gear.4.2 The purchaser shall specify the desired grade,includingthe suffix letters“RH,”in accordance with Table 1.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.15 on Bars.Current edition approved Dec.1,2016.Published December 2016.Originallyapproved in 1992.Last previous edition approved in 2011 as A914/A914M-92(2011).DOI:10.1520/A0914_A0914M-16.2For 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 SAE International(SAE),400 Commonwealth Dr.,Warrendale,PA 15096,http:/www.sae.org.*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 4.3 Band limits are shown graphically and as tabulations inFigs.2-23,inclusive.For specification purposes,one must usetabulated values of Rockwell hardness(HRC)as a function ofdistance from the quenched end of the hardenability bar,eitherin inch-pound units(sixteenths of an inch)or in SI units(millimetres).Values below 20 HRC are not specified becausesuch values are not accurate.4.3.1 Band limits shown graphically are so depicted forconvenience in estimating the hardness values at variousintermediate locations on the end quench test bar for quickcom