ASTM D5894-2016 Practică standard pentru pulverizarea cu sare/expunerea la UV în ciclurile de metal vopsit (Expunere alternativă în dulapuri de ceață/uscare și dulapuri UV/condensare)
ASTM D5894, cunoscut și ca pulverizare ciclică de sare/expunere UV pentru testarea metalelor vopsite. 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 Practică standard pentru pulverizarea cu sare/expunerea la UV în ciclurile de metal vopsit (Expunere alternativă în dulapuri de ceață/uscare și dulapuri UV/condensare)
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, ploaie, alternating wet/dry conditions, temperature changes, and outdoor ultraviolet light (340nm). This practice is designed to provide manufacturers with more realistic and better simulation tests than the more static test procedures in ASTM B117 testing. In unele cazuri, 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. in orice caz, it also contains 0.35% ammonium sulfate, which is used to reduce pH in a solution range of 5 la 5.4, rather than 6,6 la 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. De exemplu, 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.