意味と目的
5.1 屋外での塗装金属の腐食は、次のような多くの要因の影響を受けます。: 腐食性雰囲気, 雨, 結露, ultraviolet light, wet/dry cycle and temperature cycle. These factors often have synergistic effects on each other. This practice is intended to provide a more realistic simulation of the interaction of these factors than conventional testing with continuous exposure to a set of static corrosion conditions.

5.2 The results obtained from this exercise can be used to compare the relative durability of materials subjected to a particular test cycle.

5.3 No exposure test can be specified as a complete simulation of actual conditions of use in outdoor environments. Only when a rank correlation has been established for the particular material being tested can the results obtained from the exposure performed according to this practice be considered representative of the actual outdoor exposure. The relative durability of materials in actual outdoor service can vary considerably from location to location due to differences in UV radiation, wet time, 温度, contaminants, およびその他の要因. したがって, even if results from specific artificial test conditions are found to be useful for comparing the relative durability of materials exposed to specific external environments, it cannot be assumed that they can be used to determine the relative durability in different environments.

5.4 Although very tempting, it is not recommended to calculate an “acceleration factor” that relates x hours of laboratory exposure to y months of external exposure. Different materials and different formulations of the same material may have significantly different acceleration coefficients. The acceleration factor also varies according to changes in degradation rates in laboratory tests and actual outdoor exposures.

5.5 This practice is suitable for comparing the relative performance of materials tested simultaneously in the same exposure device. Since there may be differences between the same type of exposure equipment, it is not recommended to compare the amount of degradation in different equipment exposed to the same duration of material at different times or running the same test conditions. This practice should not be used to establish “合格/不合格” approvals for materials after a specific exposure period unless performance is compared relative to control materials exposed at the same time or variability in testing is rigorously quantified so that statistically significant pass/fail judgments can be made.

5.6 This practice has been found to be useful for air-dried industrial maintenance coatings on steel 3,4,5,6,7 and zinc-rich primers, but its applicability in high UV stability coating systems, such as automotive applications, has not been evaluated.

ASTM D 5894-2021 “塗装金属の周期的な塩水噴霧/UV 曝露 (または塩水噴霧/乾燥チャンバーおよび UV/コンデンサーチャンバーへの暴露)”

の範囲
1.1 The practice covers the fundamentals and operational practices of cyclic corrosion/UV exposure of paint on metal, with alternate exposure in two different cabinets: a cyclic salt spray/drying cabinet and a fluorescent UV/condensing cabinet.

1.2 This practice is limited to methods and procedures for obtaining, measuring and controlling exposure conditions. It does not specify the preparation of the specimens or the evaluation of the results.

1.3 SI 単位で表された値は標準値として考慮される必要があります。. 他の測定単位はこの規格には含まれていません.

1.4 この規格は、すべての安全問題に対処することを目的としたものではありません, もしあれば, その使用に関連する. 適切な安全性を確立するのは、この規格の使用者の責任です。, 健康および環境慣行を確認し、使用前に規制制限の適用可能性を判断するため.

1.5 この国際規格は、国際規格開発の原則に関する決定で確立された国際的に認められた標準化原則に従って開発されました。, 世界貿易機関の貿易の技術的障壁に関する委員会が発行したガイドラインと勧告.