1.1 本试验方法涵盖了在酸化沸腾氯化钠溶液中进行应力腐蚀开裂试验的程序。本试验方法在25 % （由 大量 )用磷酸将氯化钠酸化至pH 1.5。该试验方法主要涉及试验溶液和玻璃器皿，尽管建议使用特定类型的U形弯曲试样。 1.2 本试验方法旨在提供与不锈钢化学工艺行业经验更好的相关性，而非实践中更严格的沸腾氯化镁试验 第36页 在许多环境中提供了令人满意的服务的一些不锈钢在实践中容易开裂 第36页 ，但在实验室间试验期间未开裂（见第节 12 )使用该氯化钠测试方法。 1.3 沸腾氯化钠试验方法用于实验室间试验计划，以评估锻造不锈钢，包括双相（铁素体- 奥氏体）不锈钢和具有高达约33 % 镍它还可用于在铸造或焊接条件下评估这些类型的材料。 1.4 该试验方法检测成分、热处理、微观结构和应力对材料对氯化物应力腐蚀开裂敏感性的主要影响。不太可能检测到样品之间的微小差异，例如相同等级的热对热变化。 1.5 以SI单位表示的值应视为标准值。SI单位后括号中给出的值仅供参考，不视为标准值。 1.6 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建立适当的安全、健康和环境实践，并确定监管限制的适用性。 有关具体危险说明，请参见第节 8. . 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）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》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 本试验方法旨在比较合金，可作为使用前筛选材料的一种方法。一般来说，该试验方法对不锈钢比实践中的沸腾氯化镁试验更有用 第36页 沸腾氯化镁试验使材料开裂，其镍含量存在于相对耐蚀的奥氏体和双相不锈钢中，因此难以对许多使用环境进行比较和评估。 5.2 本试验方法旨在模拟水中开裂，尤其是含有氯化物的冷却水。它不用于模拟高温（大于200 °C或390 °F）与氯化物或氢氧化物混合。 注1: 在完全浸没试验中发现的抗裂度可能并不表示某些使用条件下的抗裂程度，包括暴露于水线或氯化物可能集中的气相。 5.3 如果可能，应获得与服务经验的相关性。不同的氯化物环境可以按不同的顺序排列材料。 5.4 在实验室间试验中，该试验方法开裂了退火的UNS S30400和S31600，但不开裂更耐磨的材料，例如退火的双相不锈钢或更高的镍合金，例如UNS N08020（例如20Cb- 3. 3. 不锈钢）。当暴露于实践中时，这些更具抵抗力的材料预计会开裂 第36页 作为U形弯管。耐氯化钠试验时间比UNS S30400或S31600更长的材料可用于更严格的应用。 5.5 第节中的重复性和再现性数据 12 和 附录X1 必须在使用前考虑。许多腐蚀试验的结果可能会出现实验室间变化。验收标准不属于本试验方法的一部分，如果需要，应由用户和生产商协商。

1.1 This test method covers a procedure for conducting stress-corrosion cracking tests in an acidified boiling sodium chloride solution. This test method is performed in 25 % (by mass ) sodium chloride acidified to pH 1.5 with phosphoric acid. This test method is concerned primarily with the test solution and glassware, although a specific style of U-bend test specimen is suggested. 1.2 This test method is designed to provide better correlation with chemical process industry experience for stainless steels than the more severe boiling magnesium chloride test of Practice G36 . Some stainless steels which have provided satisfactory service in many environments readily crack in Practice G36 , but have not cracked during interlaboratory testing (see Section 12 ) using this sodium chloride test method. 1.3 This boiling sodium chloride test method was used in an interlaboratory test program to evaluate wrought stainless steels, including duplex (ferrite-austenite) stainless and an alloy with up to about 33 % nickel. It may also be employed to evaluate these types of materials in the cast or welded conditions. 1.4 This test method detects major effects of composition, heat treatment, microstructure, and stress on the susceptibility of materials to chloride stress-corrosion cracking. Small differences between samples such as heat-to-heat variations of the same grade are not likely to be detected. 1.5 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. 1.6 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. For specific hazard statements, see Section 8 . 1.7 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 designed to compare alloys and may be used as one method of screening materials prior to service. In general, this test method is more useful for stainless steels than the boiling magnesium chloride test of Practice G36 . The boiling magnesium chloride test cracks materials with the nickel levels found in relatively resistant austenitic and duplex stainless steels, thus making comparisons and evaluations for many service environments difficult. 5.2 This test method is intended to simulate cracking in water, especially cooling waters that contain chloride. It is not intended to simulate cracking that occurs at high temperatures (greater than 200 °C or 390 °F) with chloride or hydroxide. Note 1: The degree of cracking resistance found in full-immersion tests may not be indicative of that for some service conditions comprising exposure to the water-line or in the vapor phase where chlorides may concentrate. 5.3 Correlation with service experience should be obtained when possible. Different chloride environments may rank materials in a different order. 5.4 In interlaboratory testing, this test method cracked annealed UNS S30400 and S31600 but not more resistant materials, such as annealed duplex stainless steels or higher nickel alloys, for example, UNS N08020 (for example 20Cb-3 3 stainless). These more resistant materials are expected to crack when exposed to Practice G36 as U-bends. Materials which withstand this sodium chloride test for a longer period than UNS S30400 or S31600 may be candidates for more severe service applications. 5.5 The repeatability and reproducibility data from Section 12 and Appendix X1 must be considered prior to use. Interlaboratory variation in results may be expected as occurs with many corrosion tests. Acceptance criteria are not part of this test method and if needed are to be negotiated by the user and the producer.