ASTM E604-18

5.1 The DT energy value is a measure of resistance to rapid progressive fracturing. In a number of applications, the enhanced resistance that may develop during about one plate thickness of crack extension from a sharp notch is of major interest. In the test method, a sufficiently long fracture path is provided so that the results serve as a measure of this property.

5.2 Fracture surfaces of nonaustenitic steels tested in their temperature transition region have areas that appear bright and areas that appear dull. The bright, faceted appearing areas are termed “cleavage” fracture, and the dull appearing areas are termed “shear” fracture after their respective mode of fracture on a micro scale.

5.3 This test method can serve the following purposes:

1.1 This test method covers the dynamic tear (DT) test using specimens that are ³/₁₆ in. to ⁵/₈ in. (5 mm to 16 mm) inclusive in thickness.

1.2 This test method is applicable to materials with a minimum thickness of ³/₁₆ in. (5 mm).

1.3 The pressed-knife procedure described for sharpening the notch tip generally limits this test method to materials with a hardness level less than 36 HRC.

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5 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.

1.6 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.