1、Designation:E224815Standard Test Method forImpact Testing of Miniaturized Charpy V-Notch Specimens1This standard is issued under the fixed designation E2248;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A
2、number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method describes notched-bar impact testing ofmetallic materials using Miniaturized Charpy V-Notch(MCVN)specimens and test appar
3、atus.It provides:(a)adescription of the apparatus,(b)requirements for inspectionand calibration,(c)safety precautions,(d)sampling,(e)dimen-sions and preparation of specimens,(f)testing procedures,and(g)precision and bias.1.2 This standard concerns Miniaturized Charpy V-Notchspecimens,for which all l
4、inear dimensions,including lengthand notch depth,are reduced with respect to a type A standardimpact test specimen in accordance with Test Methods E23.These are not the same as sub-size specimens,described inAnnex A3 of Test Methods E23,for which length,notch angleand notch depth are the same as for
5、 the standard typeACharpyspecimen.See also 1.5 below.1.3 Comparison of the MCVN data with conventionalCharpy V-Notch(CVN)data or application of the MCVN data,or both,to the evaluation of ferritic material behavior is theresponsibility of the user of this test method and is notexplicitly covered by t
6、his 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 address testing of sub-sizespecimens as discussed in Test Methods E23.The readershould understand the distinction between miniature an
7、d sub-size.Miniature specimens are shorter that sub-size specimensso that more tests can be conducted per unit volume ofmaterial.Moreover,miniature specimens are designed so thatthe stress fields which control fracture are similar to those ofconventional Test Methods E23 specimens.1.6 The MCVN test
8、may be performed using a typical TestMethods E23 test machine with suitably modified anvils andstriker or using a smaller capacity machine.1.7 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 es
9、tablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsE23 Test Methods for Notched Bar Impact Testing of Me-tallic Mat
10、erialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2298 Test Method for Instrumented Impact Testing ofMetallic Materials2.2 ISO Standards:3ISO 148 Metallic materials-Charpy pe
11、ndulum impact test-Part 1:Test methodISO 14556 Steel-Charpy V-notch pendulum impact test-Instrumented test method3.Summary of Test Method3.1 The essential features of the MCVN impact test are:(a)a suitable miniature three point bend specimen,(b)anvils andsupports on which the test specimen is placed
12、 to receive theblow of the moving mass,(c)a moving mass(striker)that hasbeen released from a sufficient height to cause the mass tobreak the specimen placed in its path,(d)a device fordetermining the energy absorbed by the broken specimen,andoptionally(e)instrumentation for measuring applied force a
13、s afunction of time during specimen loading(refer to Test MethodE2298).1This test method is under the jurisdiction of ASTM Committee E28 onMechanical Testing and is the direct responsibility of Subcommittee E28.07 onImpact Testing.Current edition approved Oct.1,2015.Published December 2015.Originall
14、yapproved in 2009.Last previous edition approved in 2013 as E224813.DOI:10.1520/E2248-15.2For 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 p
15、age onthe ASTM website.3Available from International Organization for Standardization(ISO),1,ch.dela Voie-Creuse,Case postale 56,CH-1211,Geneva 20,Switzerland,http:/www.iso.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box
16、C700,West Conshohocken,PA 19428-2959.United States1 3.2 The test consists of breaking the miniaturized specimen,notched in the middle,and supported at each end,with oneblow from a swinging pendulum under conditions definedhereafter.4.Significance and Use4.1 There are cases where it is impractical or impossible toprepare conventional CVN specimens.MCVN specimens arean alternative approach for characterizing notched specimenimpact behavior.Typical applications include MCVN speci-mens prepared from