ASTM E23-2018 pdf free download

ASTM E23-2018 pdf free download.Standard Test Methods for Notched Bar Impact Testing of Metallic Materials
1. Scope
1.1 These test methods describe notched-bar impact testing of metallic materials 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), desig- nation of test specimen orientation (see Terminology E1823), and determining the shear fracture appearance (see Annex A4). In addition, information is provided on the significance of notched-bar impact testing (see Appendix X1), and methods of measuring the center of strike (see Appendix X2). 1.2 These test methods do not address the problems associ- ated with impact testing at temperatures below –196 °C (77 K). 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3.1 Exception—Section 9 and Annex A4 provide inch- pound units 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 appro- priate safety, health, and environmental practices and deter- mine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 6. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
7. Apparatus
7.1 General Requirements: 7.1.1 The testing machine shall be a pendulum type of rigid construction. 7.1.2 The testing machine shall be designed and built to conform with the requirements given in Annex A1. 7.2 Inspection and Verification: 7.2.1 Procedures for direct verification of impact machines are provided in A2.2 and A2.3. The items listed in A2.2 require direct verification annually. 7.2.2 Procedures for indirect verification of Charpy machines, using verification specimens, are given in A2.4. Charpy impact machines require direct and indirect verification annually.
8. Test Specimens
8.1 Configuration and Orientation: 8.1.1 Specimens shall be taken from the material as speci- fied by the applicable specification. 8.1.2 The type ofspecimen chosen depends largely upon the characteristics of the material to be tested. A given specimen may not be equally satisfactory for soft nonferrous metals and hardened steels; therefore, many types of specimens are recognized. In general, sharper and deeper notches are required to distinguish differences in very ductile materials or when using low testing velocities. 8.1.3 The specimens shown in Fig. 1 and Fig. 2 are those most widely used and most generally satisfactory. They are particularly suitable for ferrous metals, excepting cast iron. 3 The Charpy specimen designations are V-notch and U-notch.N OTE 1—Keyhole notch specimen is similar to U-notch, except the notch width is 1.6 mm or less. 8.1.4 The specimens commonly found suitable for powder metallurgy materials are shown in Fig. 3 and Fig. 4. Powder metallurgy impact test specimens shall be produced following the procedure in Practices B925. The impact test results of these materials are affected by specimen orientation. Therefore, unless otherwise specified, the position of the specimen in the machine shall be such that the pendulum will strike a surface that is parallel to the compacting direction. For powder metallurgy materials the impact test results are reported as unnotched absorbed energy. 8.1.5 Sub-size and supplementary specimen recommenda- tions are given in Annex A3. 8.2 Specimen Machining: 8.2.1 When heat-treated materials are being evaluated, the specimen shall be finish machined, including notching, after the final heat treatment, unless it can be demonstrated that the impact properties ofspecimens machined before heat treatment are identical to those machined after heat treatment. 8.2.2 Notches shall be smoothly machined, but polishing has proven generally unnecessary.