1.1 本试验方法测定聚乙烯材料在规定条件下对缓慢裂纹扩展的抵抗力。 注1: 这种测试方法被称为PENT（宾夕法尼亚缺口测试）测试。 1.2 标准测试在80 °C和2.4 MPa，但在低于80的温度下进行试验是可以接受的 °C，其他应力低到足以防止延性失效，从而最终导致脆性失效。标准试验在空气环境中进行；但是，可以将试样浸入其他环境（如水或水/洗涤剂溶液）或其他液体或不同环境（如惰性气体）中，以评估不同环境中的缓慢裂纹扩展性能。 通常，聚乙烯在80℃时会因缓慢的裂纹生长而最终以脆性的方式失效 °C，如果应力等于或低于2.4 MPa 注2: 在空气以外的环境中进行测试时，建议考虑保持测试介质（例如洗涤剂溶液）的功效，以最大限度地减少老化的影响。 1.3 该试验方法适用于从压模板上切下的试样。 2. 看见 附录X1 有关管道试样的信息。 1.4 以国际单位制表示的数值应视为标准。SI单位后括号中给出的值仅供参考，不被视为标准值。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。 本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 该试验方法可用于测量聚乙烯材料模塑板在加速条件下（如80 °C，2。 4. MPa应力，并具有尖锐的缺口。 5.2 测试时间或失效时间取决于以下测试参数:温度；强调缺口深度；以及试样几何形状。温度、应力和缺口深度的增加会缩短失效时间。可能影响测试结果（失效时间）的材料参数不受实验室控制，包括:颜料（颜色或炭黑）和颜料的载体树脂，或两者兼而有之。因此，在报告试验时间或失效时间时，应规定试验的所有条件。 注4: 失效时间也会受到试样中颜料（颜色或炭黑）分散和分布程度的影响。 试验方法 D5596 和ISO 18553提供了评估颜料分散和分布程度的方法

1.1 This test method determines the resistance of polyethylene materials to slow crack growth under conditions specified within. Note 1: This test method is known as PENT (Pennsylvania Notch Test) test. 1.2 The standard test is performed at 80 °C and at 2.4 MPa, but it shall be acceptable to conduct tests at a temperature below 80 °C and with other stresses low enough to preclude ductile failure and thereby eventually induce brittle type of failure. The standard test is conducted in an air environment; however, it shall be acceptable to immerse test specimens in an alternate environment such as water or a water/detergent solution, or other liquid or a different environment such as an inert gas to evaluate slow crack growth performance in different environments. Generally, polyethylenes will ultimately fail in a brittle manner by slow crack growth at 80 °C if the stress is at or below 2.4 MPa Note 2: When testing in environments other than air, it is recommended to consider maintaining the efficacy of the test media (for example, a detergent solution) to minimize any effect of aging. 1.3 The test method is for specimens cut from compression molded plaques. 2 See Appendix X1 for information relating to specimens from pipe. 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. 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. ====== Significance And Use ====== 5.1 This test method is useful to measure the slow crack growth resistance of molded plaques of polyethylene materials at accelerated conditions such as 80 °C, 2.4 MPa stress, and with a sharp notch. 5.2 The testing time or time to failure depends on the following test parameters: temperature; stress; notch depth; and specimen geometry. Increasing temperature, stress, and notch depth decrease the time to failure. Material parameters, not controlled by the laboratory, that could impact the test results (time to failure) are: pigment (color or carbon black) and the carrier resin for the pigment, or both. Thus, in reporting the test time or time to failure, all the conditions of the test shall be specified. Note 4: Time to failure can also be affected by the degree of pigment (color or carbon black) dispersion and distribution within the test specimen. Test Method D5596 and ISO 18553 provide methods for assessing the degree of dispersion and distribution of the pigment