1.1 本规程涵盖了金属、合金和其他材料在天然表层海水中的暴露条件，例如海湾、港口、航道等中常见的金属、合金和其他材料， 2. 与深海测试形成对比。 3. 本规程涵盖全浸、潮汐区和相关飞溅以及喷雾区暴露。 2. 4. 1.2 本规程规定了进行海水暴露试验时应遵循的一般程序，以便从一个位置到另一个位置进行有意义的比较。 1.3 本规程确定了评估天然表面海水对暴露材料影响的推荐程序。 1.4 以国际单位制表示的数值应视为标准值。国际单位制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、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（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====== 4.1 本文所述程序建议用于评估暴露于静态或局部潮流条件下的材料的腐蚀或海洋污垢行为，或两者兼而有之。 4.1.1 本规程不包括高海水流速的影响或从源头运输的海水中材料的行为。 4.1.2 本规程的某些方面可能适用于储罐和水槽中的测试，这些储罐和水槽连续提供直接从源头泵送的表面海水。 此外，某些方面也可能适用于深海测试。 注1: 指导 G78型 为在受控海水试验条件下进行缝隙腐蚀试验提供指导。 4.2 虽然测试的持续时间可能由测试目标决定，但通常使用六个月或一年以上的暴露时间来最小化与季节变化或地理位置或两者相关的环境变量的影响。另请参阅 7.3 试验持续时间建议。 4.3 所述程序适用于简单试板、焊接试板或配置用于评估裂缝影响的试板或两者的暴露，如指南中所述 G78型 . 此外，它们对于测试实际部件和装配组件也很有用。 4.4 谨慎的做法是，按照试验方法所述，包括具有已知耐海水腐蚀或污垢或两者兼有的控制材料 D3623 . 注2: ASTM全球海水腐蚀性研究中包含的材料包括UNS K01501（碳钢）、UNS C70600（90/10 CuNi）和UNS A95086（5086-H116 Al）。 2. 4. 注3: 在评估铝合金的情况下，应注意试样靠近铜或高铜的位置- 含合金。在某些情况下，仅对试样进行电气隔离以防止双金属（电偶）腐蚀是不够的；附近腐蚀的铜或铜基合金中的铜离子会沉积在铝上，加速铝的腐蚀。

1.1 This practice covers conditions for the exposure of metals, alloys, and other materials in natural surface seawater such as those typically found in bays, harbors, channels, and so forth, 2 as contrasted with deep ocean testing. 3 This practice covers full immersion, tidal zone and related splash, and spray zone exposures. 2, 4 1.2 This practice sets forth general procedures that should be followed in conducting seawater exposure tests so that meaningful comparisons may be made from one location to another. 1.3 This practice identifies recommended procedures for evaluating the effects of natural surface seawater on the materials exposed. 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 ====== 4.1 The procedures described herein are recommended for evaluating the corrosion or marine fouling behavior, or both, of materials exposed to quiescent or local tidal flow conditions, or both. 4.1.1 This practice is not intended to cover the influence of high seawater velocity or the behavior of materials in seawater which has been transported from its source. 4.1.2 Some aspects of this practice may be applicable to testing in tanks and troughs, which are continuously provided with surface seawater pumped directly from the source. Additionally, some aspects may also be applicable to deep ocean testing. Note 1: Guide G78 provides guidance for conducting crevice corrosion tests under controlled seawater test conditions. 4.2 While the duration of testing may be dictated by the test objectives, exposures of more than six months or one year are commonly used to minimize the effects of environmental variables associated with seasonal changes or geographic location, or both. Refer also to 7.3 for test duration recommendations. 4.3 The procedures described are applicable for the exposure of simple test panels, welded test panels, or those configured to assess the effects of crevices, or both, such as those described in Guide G78 . In addition, they are useful for testing of actual components and fabricated assemblies. 4.4 It is prudent to include control materials with known resistance to seawater corrosion or fouling, or both, as described in Test Method D3623 . Note 2: Materials which have been included in ASTM Worldwide Seawater Corrosivity Studies include UNS K01501 (carbon steel), UNS C70600 (90/10 CuNi) and UNS A95086 (5086-H116 Al). 2, 4 Note 3: In the case of evaluations of aluminum alloys, care should be exercised in the location of specimens near copper or high copper-containing alloys. In some instances, it is not sufficient to simply electrically isolate specimens to prevent bi-metallic (galvanic) corrosion; copper ions from nearby corroding copper or copper-base alloys can deposit on aluminum and accelerate its corrosion.