1.1 本试验方法包括高强度2XXX的恒定浸渍剥离腐蚀（EXCO）试验程序（见 注2 )以及7XXX系列铝合金。 注1: 此测试方法最初是为了研究和开发目的而开发的；然而，在具体的材料规范中，它被引用，适用于评估生产材料（参见第节 14 关于精度和偏差）。 注2: 一些Al-Cu-Li合金被登记在2xxx家族中。据报道，该试验方法不代表各种Al-Cu-Li合金在淬火和人工时效状态下在室外大气中的性能。 2. 1.2 本试验方法适用于所有锻造产品，如传统铸锭冶金工艺生产的板材、板材、挤压件和锻件。 1.3 该试验方法可用于任何形式的试样或零件，这些试样或零件可浸入试验溶液中。 1.4 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。 1.5 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 此测试方法最初是为了研究和开发目的而开发的；然而，在具体的材料规范中，它被引用，适用于评估生产材料（参见第节 14 关于精度和偏差）。 5.2 该试验方法的使用为这些合金在各种户外服务中，特别是在海洋和工业环境中的剥落腐蚀行为提供了有用的预测。 5. 试验溶液具有很强的腐蚀性，代表了更严重的环境服务类型，当然不包括自然环境中不太可能遇到的异常化学品。 5.3 剥落评级是任意选择的，以说明在该测试中对剥落的抵抗力范围很广。 然而，对于给定的合金，EXCO试验额定值和实际使用条件之间是否可以建立相关性还有待确定。例如，据报道 6. Al-Zn-Mg-Cu合金的样品在48 在暴露于海岸大气的六到九年中，EXCO测试没有产生超过少量的初始剥落（EA），而在大多数情况下，ED级材料在海岸大气中一年内产生严重剥落。

1.1 This test method covers a procedure for constant immersion exfoliation corrosion (EXCO) testing of high-strength 2XXX (see Note 2 ) and 7XXX series aluminum alloys. Note 1: This test method was originally developed for research and development purposes; however, it is referenced, in specific material specifications, as applicable for evaluating production material (refer to Section 14 on Precision and Bias). Note 2: Some Al-Cu-Li alloys are registered in the 2xxx family. This test method has been reported as non representative of performance in outdoor atmospheres for various Al-Cu-Li alloys in both as-quenched and artificially aged tempers. 2 1.2 This test method applies to all wrought products such as sheet, plate, extrusions, and forgings produced from conventional ingot metallurgy process. 1.3 This test method can be used with any form of specimen or part that can be immersed in the test solution. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 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 was originally developed for research and development purposes; however, it is referenced, in specific material specifications, as applicable for evaluating production material (refer to Section 14 on Precision and Bias). 5.2 Use of this test method provides a useful prediction of the exfoliation corrosion behavior of these alloys in various types of outdoor service, especially in marine and industrial environments. 5 The test solution is very corrosive and represents the more severe types of environmental service, excluding, of course, unusual chemicals not likely to be encountered in natural environments. 5.3 The exfoliation ratings were arbitrarily chosen to illustrate a wide range in resistance to exfoliation in this test. However, it remains to be determined whether correlations can be established between EXCO test ratings and realistic service conditions for a given alloy. For example, it has been reported 6 that samples of Al-Zn-Mg-Cu alloys rated EA or P in a 48 h EXCO test did not develop more than a slight amount of incipient exfoliation (EA) during six- to nine-year exposures to seacoast atmospheres, whereas, ED rated materials in most cases developed severe exfoliation within a year in the seacoast atmosphere.