What is a salt spray test?

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This post was last edited by ljtjbx on 10/09/2015 at 10:16. What is a salt spray test? The salt spray test is one of the important indicators for evaluating the corrosion resistance of electrophoretic coatings. So what is a salt spray test? What are the categories? Do you know that too? We have already introduced the \"Salt Spray Test Standards\" to you before; now, Feiyang Coatings, a manufacturer of cathodic electrophoretic paints, will provide an explanation. Most cases of corrosion of electrophoretic coatings occur in atmospheric environments, which contain corrosive elements and factors such as oxygen, humidity, temperature variations, and pollutants. Salt spray corrosion is a common and highly destructive form of atmospheric corrosion. The salt spray mentioned here refers to an atmosphere containing chlorides; its main corrosive component is sodium chloride, a chloride salt found in the oceans, and it originates primarily from the oceans as well as saline-alkali areas on land. The corrosion of the electrophoretic paint surface by salt spray is caused by chloride ions penetrating the oxide and protective layers on the surface of the electrophoretic paint and undergoing electrochemical reactions with the underlying metal. At the same time, chloride ions possess a certain amount of hydration energy; they can be adsorbed in the pores and cracks of the electrophoretic paint, displacing the oxygen in the oxide layer. This transforms insoluble oxides into soluble chlorides, thereby changing a passivated surface into an active one. It causes extremely severe adverse reactions to the product. Salt spray tests are divided into two main categories: one is natural environment exposure tests, and the other is artificially accelerated simulated salt spray environment tests. The artificial salt spray environment testing method involves using a testing apparatus with a certain volume – a salt spray test chamber – in which a salt spray environment is created artificially to evaluate the resistance of electrophoretic coatings to salt spray corrosion. Compared to the natural environment, the salt concentration of chlorides in its salt spray environment can be several times or even dozens of times higher than that in normal natural salt sprays, which **increases the corrosion rate**. Additionally, the time required to obtain results from salt spray testing on products is also **reduced**. If a product sample is tested in a natural exposure environment, it may take up to 1 year for corrosion to occur, whereas under artificially simulated salt spray conditions, similar results can be obtained in just 24 hours.