Norma Astm E-23

NOTICE: This standard has either been superseded and replaced by a new version or discontinued. Contact ASTM International (www.astm.org) for the latest information.
Designation: E 23 – 00

Standard Test Methods for

Notched Bar Impact Testing of Metallic Materials1
This standard is issued under the fixed designation E 23; 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 (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense.

1. Scope 1.1 These test methods describe notched-bar impact testing of metallicmaterials by the Charpy (simple-beam) test and the Izod (cantilever-beam) test. They give the requirements for: test specimens, test procedures, test reports, test machines (see Annex A1) verifying Charpy impact machines (see Annex A2), optional test specimen configurations (see Annex A3), precracking Charpy V-notch specimens (see Annex A4), designation of test specimen orientation (see AnnexA5), and determining the percent of shear fracture on the surface of broken impact specimens (see Annex A6). In addition, information is provided on the significance of notched-bar impact testing (see Appendix X1), methods of measuring the center of strike (see Appendix X2), and the availability of Charpy V-notch verification specimens (see Appendix X3). 1.2 These test methods do not address theproblems associated with impact testing at temperatures below –196 °C (–320 °F, 77 °K). 1.3 The values stated in SI units are to be regarded as the standard. Inch-pound units are provided for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safetyand health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 5. 2. Referenced Documents 2.1 ASTM Standards: E 177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods2 E 399 Test Method for Plane-Strain Fracture Toughness of Metallic Materials3 E 604 Test Method for Dynamic Tear Energy ofMetallic Materials3 E 691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method2
1 These test methods are under the jurisdiction of ASTM Committee E-28 on Mechanical Testing and are the direct responsibility of Subcommittee E28-07 on impact testing. Current edition approved May 10, 2000. Published August 2000. Originally published as E 23 – 33 T. Last previousedition E 23 – 98. 2 Annual Book of ASTM Standards, Vol 14.02. 3 Annual Book of ASTM Standards, Vol 03.01.

E 1271 Practice for Qualifying Charpy Verification Specimens of Heat-treated Steel3 E 1313 Guide for Recommended Formats for Data Records Used in Computerization of Mechanical Test Data for Metals4 3. Summary of Test Method 3.1 The essential features of an impact test are: a suitable specimen(specimens of several different types are recognized), an anvil or support on which the test specimen is placed to receive the blow of the moving mass, a moving mass that has sufficient energy to break the specimen placed in its path, and a device for measuring the energy absorbed by the broken specimen. 4. Significance and Use 4.1 These test methods of impact testing relate specifically to thebehavior of metal when subjected to a single application of a force resulting in multi-axial stresses associated with a notch, coupled with high rates of loading and in some cases with high or low temperatures. For some materials and temperatures the results of impact tests on notched specimens, when correlated with service experience, have been found to predict the likelihood of brittle fracture...