ASTM D5894 المعروف أيضًا باسم رش الملح الدوري/التعرض للأشعة فوق البنفسجية لاختبار المعادن المطلية. The rationale for this test is to expose the sample to alternating exposures in a fog/drying cabinet and a UV/condensing cabinet. This practice is used to paint metal samples. It uses alternating one-week cycles of cyclic corrosion and wet/dry cycles, based on ASTM G85 tests, Appendix V and fluorescent UV exposure based on ASTM G154 tests.

ASTM D5894-2016 الممارسة القياسية لرذاذ الملح/التعرض للأشعة فوق البنفسجية في الدورات المعدنية المطلية (التعرض بالتناوب في خزانات الضباب/التجفيف وخزانات الأشعة فوق البنفسجية/التكثيف)

ASTM D5894 test uses and factors

ASTM D5894 is used to simulate outdoor corrosion of painted metals. It simulates a number of environmental factors that work together at the same time, such as corrosive environments, مطر, alternating wet/dry conditions, temperature changes, and outdoor ultraviolet light (340نانومتر). This practice is designed to provide manufacturers with more realistic and better simulation tests than the more static test procedures in ASTM B117 testing. في بعض الحالات, the cryogenic cycle can be further added to extend its range.

The mist electrolyte solution used in this practice is only 0.5% in sodium chloride and 5% in standard salt spray tests. لكن, it also contains 0.35% ammonium sulfate, which is used to reduce pH in a solution range of 5 ل 5.4, rather than 6,6 ل 7 for salt spray tests.

For all accelerated burn-in tests, there is no algorithm that allows the measurement of the “time compression factor” when testing ASTM D5894. A safe way to establish a good temporal correlation is to insert control samples of products with known field performance for comparison. The ASTM D5894 test can also be modified to better simulate your specific application. على سبيل المثال, there are different formulations of corrosive electrolytes available for ASTM G85.

ASTM D5894 has been found to be useful for air drying industrial maintenance coatings on steel and zinc primers for cathodic protection.