ASTM E399-20a

5.2.1 In research and development, to establish in quantitative terms significant to service performance, the effects of metallurgical variables such as composition or heat treatment, or of fabricating operations such as welding or forming, on the fracture toughness of new or existing materials.

5.2.2 In service evaluation, to establish the suitability of a material for a specific application for which the stress conditions are prescribed and for which maximum flaw sizes can be established with confidence.

5.2.3 For specifications of acceptance and manufacturing quality control, but only when there is a sound basis for specifying minimum 1.1?This test method covers the determination of fracture toughness (1.1.1?The K_Ic test procedure is described in the main body of this test standard and is a mandatory part of the testing and results reporting procedure for this test method. The 1.1.2?The K_Isi test procedure is described in Appendix X1 and is an optional part of this test method. The K_Isi test procedure is based on a fixed amount of crack extension of 0.5 mm, and as a result, Note 1:?Plane-strain fracture toughness tests of materials thinner than 1.6 mm (0.063 in.) that are sufficiently brittle (see 7.1) can be made using other types of specimens 1.2?This test method is divided into two parts. The first part gives general recommendations and requirements for testing and includes specific requirements for the K_Ic test procedure. The second part consists of Annexes that give specific information on displacement gage and loading fixture design, special requirements for individual specimen configurations, and detailed procedures for fatigue precracking. Additional annexes are provided that give specific procedures for beryllium and rapid-force testing, and the 1.3?General information and requirements common to all specimen configurations:

1.4?Specific requirements related to test apparatus:

1.5?Specific requirements related to individual specimen configurations:

1.6?Specific requirements related to special test procedures:

1.7?The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.8?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 safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.9?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.