1.1这些试验方法涵盖了在百万分之一范围内测定隔热材料中水溶性氯化物、氟化物、硅酸盐和钠离子的实验室程序。 1.2应根据实验室能力和所需设备的可用性，以及离子浓度和萃取溶液中任何可能的离子干扰的适当性，选择每种离子测定所需的测试方法之一。 1.3以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 ====意义和用途====== 研究表明，除卤化物离子外，氯化物；当氟离子沉积并集中在奥氏体不锈钢表面时，在没有抑制离子的情况下，会导致外部应力腐蚀开裂（ESCC）。ESCC特有的两种广泛使用的绝缘规范允许使用相同的测试方法 C692型 和 C871 用于评估绝缘材料。在评估可萃取离子时，这两个规范都要求氟离子与氯离子一起。 氯化物（和氟化物）可以是绝缘材料或环境的成分，也可以是两者的成分。绝缘层中或环境中的水分会导致氯化物（和氟化物）通过绝缘层迁移，并集中在高温不锈钢表面。 已发现，绝缘中存在的钠和硅酸盐离子可抑制氯化物（和氟化物）离子引起的外部应力腐蚀开裂，无论此类离子是来自绝缘本身还是来自外部。 此外，如果钠和硅酸盐离子与氯化物（和氟化物）离子的比率在绝缘中处于一定比例，则可防止或至少减轻因绝缘中存在氯化物（和氟化物）而导致的外部应力腐蚀开裂（另见规范） C795 ).

1.1 These test methods cover laboratory procedures for the determination of water-leachable chloride, fluoride, silicate, and sodium ions in thermal insulation materials in the parts per million range. 1.2 Selection of one of the test methods listed for each of the ionic determinations required shall be made on the basis of laboratory capability and availability of the required equipment and appropriateness to the concentration of the ion and any possible ion interferences in the extraction solution. 1.3 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. 1.4 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 and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== Research has demonstrated that in addition to the halide ion chloride; fluoride ions, when deposited and concentrated on the surface of austenitic stainless steel, can contribute to external stress corrosion cracking (ESCC) in the absence of inhibiting ions. Two widely used insulation specifications that are specific to ESCC allow the use of the same Test Methods C692 and C871 for evaluation of insulation materials. Both specifications require fluoride ions to be included with chloride ions when evaluating the extractable ions. Chlorides (and fluorides) can be constituents of the insulating material or of the environment, or both. Moisture in the insulation or from the environment can cause chlorides (and fluorides) to migrate through the insulation and concentrate at the hot stainless steel surface. The presence of sodium and silicate ions in the insulation has been found to inhibit external stress corrosion cracking caused by chloride (and fluoride) ions, whether such ions come from the insulation itself or from external sources. Furthermore, if the ratio of sodium and silicate ions to chloride (and fluoride) ions is in a certain proportion in the insulation, external stress corrosion cracking as a result of the presence of chloride (and fluoride) in the insulation will be prevented or at least mitigated (see also Specification C795 ).