ASTM E 1450:2024

1.1 This test method describes procedures for the tension testing of structural alloys in liquid helium. The format is similar to that of other ASTM tension testing standards, but the contents includes modifications for cryogenic testing that require special apparatus, smaller specimens, and concern for discontinous yielding, adiabatic heating, and strain-rate effects. 1.2 To conduct a tension test by this standard, the specimen in a tensile cryostat is fully submerged in normal liquid helium (He I) and tested using crosshead displacement control at a nominal strain rate of 10⁻³ mm/mm/s or less. Tests using force control or high strain rates are not considered. 1.3 This test method specifies methods for the measurement of yield strength, tensile strength, elongation, and reduction of area. The determination of the Young's modulus is treated in Test Method E111 . Note 1: The boiling point of normal liquid helium (He I) at sea level is 4.2 K (−269 °C or −452.1 °F or 7.6 °R). It decreases with geographic elevation and is 4.0 K (−269.2 °C or −452.5 °F or 7.2 °R) at the National Institute of Standards and Technology in Colorado, 1677 m (5500 ft) above sea level. In this standard the temperature is designated 4 K. 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units 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. See Section 5 . 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.

77.040.10