ASTM_E_2298_-_15.pdf

Designation:E229815Standard Test Method forInstrumented Impact Testing of Metallic Materials1This standard is issued under the fixed designation E2298;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.Scope*1.1 This test method establishes the requirements for per-forming instrumented Charpy V-Notch(CVN)and instru-mented Miniaturized Charpy V-Notch(MCVN)impact tests onmetallic materials.This method,which is based on experiencedeveloped testing steels,provides further information(inaddition to the total absorbed energy)on the fracture behaviorof the tested materials.Minimum requirements are given formeasurement and recording equipment such that similar sen-sitivity and comparable total absorbed energy measurements tothose obtained in Test Methods E23 and E2248 are achieved.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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:2A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsE4 Practices for Force Verification of Testing MachinesE23 Test Methods for Notched Bar Impact Testing of Me-tallic MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2248 Test Method for Impact Testing of MiniaturizedCharpy V-Notch Specimens2.2 ISO Standard:ISO 14556 SteelCharpy V-notch Pendulum ImpactTestsInstrumented Test Method33.Terminology3.1 DefinitionsThe symbols and definitions applicable toinstrumented impact testing are indicated in Table 1.4.Summary of Test Method4.1 This test method prescribes the requirements for instru-mented CVN and MCVN impact tests in accordance with TestMethods E23 and E2248.The E23 and E2248 tests consist ofbreaking by one blow from a swinging pendulum,underconditions defined hereafter,a specimen notched in the middleand supported at each end.In order to establish the impactforce-displacement diagram,it is necessary to instrument thestriker with strain gages4and measure the voltage as a functionof time during the impact event.The voltage-time curve isconverted to the force-time curve through a suitable staticcalibration.The force-displacement relationship is then ob-tained by double integration of the force-time curve.The areaunder the force-displacement curve corresponds to the energyabsorbed by the specimen during the test.4.2 Force-displacement curves for different steels and dif-ferent temperatures can vary even though the areas under thecurves and the absorbed energies are identical.If the force-displacement curves are divided into a number of characteristicparts,various phases of the test with characteristic forces,displacements,and energies can be deduced.These character-istic values provide additional information about the fracturebehavior of the specimen.4.3 Application of instrumented test data to the evaluationof material behavior is the responsibility of the user of this testmethod.5.Significance and Use5.1 Instrumented impact testing provides an independentmeasurement of the total absorbed energy associated with1This 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.Originallyapproved in 2009.Last previous edition approved in 2013 as E229813a.DOI:10.1520/E2298-15.2For 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 page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.4This test method refers to strikers instrumented with strain gages.However,theuse of piezoelectric load cells or accelerometers is not excluded,provided theirtemperature sensitivity is properly accounted for.*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 fracturing CVN or MCVN specimens for test machinesequipped with a dial and/or optical encoder.5.2 Instrumented impact testing is particularly effective inMCVN testing since the resolution of a calibrated strain-gagedstriker does not necessarily decrease with the magnitud