1.1 本规程涵盖了在两个不同的柜中使用交替暴露周期，在金属上进行油漆循环腐蚀/紫外线暴露的基本原理和操作规程:循环盐雾/干燥柜和荧光紫外线/冷凝柜。 1.2 本规程仅限于获取、测量和控制暴露条件和程序的方法。它没有规定样本制备或结果评估。 1.3 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 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、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（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 涂漆金属的室外腐蚀受到许多因素的影响，包括:腐蚀性大气、雨水、冷凝露水、紫外线、干湿循环和温度循环。这些因素通常会相互产生协同效应。与连续暴露在静态腐蚀条件下的传统试验相比，本实践旨在提供更真实的这些因素相互作用的模拟。 5.2 从该实践中获得的结果可用于比较受所用特定试验循环影响的材料的相对耐久性。 5.3 不能将任何单次暴露试验指定为完全模拟室外环境中的实际使用条件。只有在确定了所测试的特定材料的秩相关程度时，根据本规程进行的暴露获得的结果才能被视为实际室外暴露的代表。由于紫外线辐射、湿润时间、温度、污染物和其他因素的差异，实际室外服务中材料的相对耐久性在不同位置可能会有很大差异。 因此，即使发现特定人工试验条件的结果有助于比较暴露在特定外部环境中的材料的相对耐久性，也不能假设它们有助于确定不同环境的相对耐久性。 5.4 尽管这很诱人，但不建议计算与此相关的“加速因子” x 实验室暴露时间 y 室外暴露数月。同一材料的不同材料和不同配方可能具有显著不同的加速因子。加速因子也因实验室试验和实际室外暴露中降解速率的变化而变化。 5.5 本规程最好用于比较在同一曝光装置中同时测试的材料的相对性能。由于同一类型暴露装置之间可能存在差异，不建议比较在不同时间暴露相同持续时间的材料中的降解量，或在运行相同测试条件的单独装置中的降解量。除非与同时暴露的对照材料进行性能比较，或严格量化试验中的可变性，以便作出具有统计意义的通过/失败判断，否则本规程不应用于在特定暴露期后建立材料的“通过/失败”批准。 5.6 这种做法对于钢上的风干工业维护涂料非常有用 3. , 4. , 5. , 6. , 7. 和富锌底漆，但其适用性尚未评估为高度紫外线稳定涂层系统，如汽车应用。

1.1 This practice covers basic principles and operating practice for cyclic corrosion/UV exposure of paints on metal, using alternating periods of exposure in two different cabinets: a cycling salt fog/dry cabinet, and a fluorescent UV/condensation cabinet. 1.2 This practice is limited to the methods of obtaining, measuring, and controlling exposure conditions, and procedures. It does not specify specimen preparation nor evaluation of results. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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, 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 The outdoor corrosion of painted metals is influenced by many factors, including: corrosive atmospheres, rain, condensed dew, UV light, wet/dry cycling, and temperature cycling. These factors frequently have a synergistic effect on one another. This practice is intended to provide a more realistic simulation of the interaction of these factors than is found in traditional tests with continuous exposure to a static set of corrosive conditions. 5.2 Results obtained from this practice can be used to compare the relative durability of materials subjected to the specific test cycle used. 5.3 No single exposure test can be specified as a complete simulation of actual use conditions in outdoor environments. Results obtained from exposures conducted according to this practice can be considered as representative of actual outdoor exposures only when the degree of rank correlation has been established for the specific materials being tested. The relative durability of materials in actual outdoor service can be very different in different locations because of differences in UV radiation, time of wetness, temperature, pollutants, and other factors. Therefore, even if results from a specific artificial test condition are found to be useful for comparing the relative durability of materials exposed in a particular exterior environment, it cannot be assumed that they will be useful for determining relative durability for a different environment. 5.4 Even though it is very tempting, it is not recommended to calculate an “acceleration factor” relating x hours of laboratory exposure to y months of exterior exposure. Different materials and different formulations of the same material can have significantly different acceleration factors. The acceleration factor also varies depending on the variability in rate of degradation in the laboratory test and in actual outdoor exposure. 5.5 This practice is best used to compare the relative performance of materials tested at the same time in the same exposure device. Because of possible variability between the same type of exposure devices, it is not recommended to compare the amount of degradation in materials exposed for the same duration at separate times, or in separate devices running the same test condition. This practice should not be used to establish a “pass/fail” approval of materials after a specific period of exposure unless performance comparisons are made relative to a control material exposed simultaneously, or the variability in the test is rigorously quantified so that statistically significant pass/fail judgments can be made. 5.6 This practice has been found useful for air-dry industrial maintenance paints on steel 3 , 4 , 5 , 6 , 7 and zinc-rich primers but its applicability has not yet been assessed for highly UV-stabilized coating systems, such as for automotive applications.