标准摘要
[中文适用范围]： ISO 6892 的这一部分规定了金属材料在液氦（沸点为 –269 °C 或 4,2 K，指定为 4 K）中进行拉伸测试的方法，并定义了可以测定的机械性能。 ISO 6892 的这一部分也适用于低温（低于 –196 °C 或 77 K）下的拉伸测试，这需要特殊的设备、较小的测试件，并考虑锯齿状屈服、绝热加热和应变率效应。 为了根据 ISO 6892 本部分在 4 K 下进行拉伸测试，将安装在低温恒温器中的测试件完全浸入液氦 (He) 中，并使用标称应变率为 10−3 s−1 或 10−3 s−1 的位移控制进行测试较少的。 注：稀有 3He 同位素的沸点为 3,2 K。 通常，测试在 4He 或高浓度 4He 的 3He 和 4He 混合物中进行。 因此，如前所述，温度为 4 K。 [外文原描述]： ISO 6892-4:2015 specifies the method of tensile testing of metallic materials in liquid helium (the boiling point is ?269 °C or 4,2 K, designated as 4 K) and defines the mechanical properties that can be determined. This part of ISO 6892 may apply also to tensile testing at cryogenic temperatures (less than ?196 °C or 77 K), which requires special apparatus, smaller test pieces, and concern for serrated yielding, adiabatic heating, and strain-rate effects. To conduct a tensile test according to this part of ISO 6892 at 4 K, the test piece installed in a cryostat is fully submerged in liquid helium (He) and tested using displacement control at a nominal strain rate of 10−3 s−1 or less. NOTE The boiling point of the rare 3He isotope is 3,2 K. Usually, the tests are performed in 4He or a mixture of 3He and 4He with a high concentration of 4He. Therefore, the temperature is, as designated before, 4 K.
英文名称Metallic materials — Tensile testing — Part 4: Method of test in liquid helium