1.1本试验方法包括两个实验室评估隔热材料的程序，以确定隔热材料是否因绝缘内的可溶性氯化物而导致奥氏体不锈钢的外部应力腐蚀开裂（ESCC）。本实验室程序无意涵盖所有可能导致ESCC的现场条件。 1.2虽然1977年版的本试验方法（Dana试验）仅适用于芯吸型绝缘，但本版本中的程序旨在适用于所有绝缘材料，包括水泥，其中一些材料在按照1977年版进行试验时会分解。 芯吸绝缘材料是指当部分（50%-75%）浸入水中很短时间（10分钟或更短）时，材料会润湿。 1.3这些程序主要用于特定制造商产品的基本化学成分资格的生产前测试，而不是用于持续质量保证或生产批次合规性的常规测试。另一方面，试验方法C 871用于确认之前通过本试验方法发现可接受的后续绝缘批次的可接受化学特性。 1.4以英寸-磅为单位的数值应视为标准值。括号中给出的值仅供参考。 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====== 某些奥氏体不锈钢合金的一个固有特征是，当暴露在某些腐蚀环境中时，它们在应力点处容易开裂。 ESCC的机理很复杂，尚未完全理解，但显然与某些冶金性能有关。氯离子集中在应力点将催化裂纹的形成。据报道，使用测试方法C 692（滴水测试）的测试技术，其他卤化物离子对ESCC的促进程度与氯化物不同。 3. 氯化物在许多环境中很常见，因此应特别注意保护奥氏体不锈钢免受氯化物污染。 鉴定试验表明，大多数隔热材料本身不会导致应力腐蚀开裂。 然而，当暴露在高温（沸点范围）、含有氯化物、水分和氧气的环境中时，一些绝缘系统充当收集介质，在加热的不锈钢表面传输和浓缩氯化物。如果不存在水分，氯盐就不会迁移，也不会因氯化物污染绝缘而发生应力腐蚀开裂。 可以使用专门配制的绝缘材料，通过修改基本成分或加入某些化学添加剂来抑制氯化物存在下的应力腐蚀开裂。 Karnes记录了28天测试测量绝缘材料腐蚀电位的能力， 4. 其数据似乎已用于构建规范C 795中使用的可接受曲线 和其他规格。 本试验方法（C 692）中使用的所有试样的金属应合格（见第 13 )为了确定在试验条件下，氯离子会导致金属开裂，而仅去离子水不会导致开裂。

1.1 This test method covers two procedures for the laboratory evaluation of thermal insulation materials to determine whether they contribute to external stress corrosion cracking (ESCC) of austenitic stainless steel due to soluble chlorides within the insulation. This laboratory procedure is not intended to cover all of the possible field conditions that contribute to ESCC. 1.2 While the 1977 edition of this test method (Dana test) is applicable only to wicking-type insulations, the procedures in this edition are intended to be applicable to all insulating materials, including cements, some of which disintegrate when tested in accordance with the 1977 edition. Wicking insulations are materials that wet through and through when partially (50 to 75 %) immersed in water for a short period of time (10 min or less). 1.3 These procedures are intended primarily as a preproduction test for qualification of the basic chemical composition of a particular manufacturer's product and are not intended to be routine tests for ongoing quality assurance or production lot compliance. Test Methods C 871, on the other hand, is used for confirmation of acceptable chemical properties of subsequent lots of insulation previously found acceptable by this test method. 1.4 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only. 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 ====== An inherent characteristic of some alloys of austenitic stainless steel is their tendency to crack at stress points when exposed to certain corrosive environments. The mechanisms of ESCC are complex and not completely understood but are apparently related to certain metallurgical properties. Chloride ions concentrated at a stress point will catalyze crack formation. It has been reported that other halide ions do not promote ESCC to the same degree as does chloride using the test technology of Test Method C 692 (drip test). 3 Chlorides are common to many environments, so great care shall be taken to protect austenitic stainless steel from chloride contamination. Most thermal insulations will not, of themselves, cause stress corrosion cracking as shown by qualification tests. When exposed to elevated-temperature (boiling point range), environments containing chlorides, moisture, and oxygen, however, some insulation systems act as collecting media, transmigrating and concentrating chlorides on heated stainless steel surfaces. If moisture is not present, the chloride salts cannot migrate, and stress corrosion cracking because of chloride-contaminated insulation cannot take place. Insulation materials are available that are specially formulated to inhibit stress corrosion cracking in the presence of chlorides through modifications in basic composition or incorporation of certain chemical additives. The ability of the 28-day test to measure the corrosion potential of insulation materials is documented by Karnes, 4 whose data appear to have been used for construction of the acceptability curve used in Specification C 795 and other specifications. The metal for all of the coupons used in this test method (C 692) shall be qualified (see Section 13 ) to ascertain that under conditions of the test, chloride ions will cause the metal to crack, and deionized water alone will not cause cracks.