Does the magnet look rusty? This situation is mainly NdFeB magnets, also known as NdFeB strong magnets. You may also ask why NdFeB magnets rust and produce a lot of rust spots? Reason analysis of rust spot on NdFeB magnet:
Under normal circumstances, the surface of the magnet has a coating (of course, it is also required not to electroplate the NdFeB magnet, and some concentrated magnets do not need electroplating, and the appearance is similar to ferrite), and does not rust, which usually produces rust spots, because it is in a relatively high humidity environment, and the air flow in the working environment is very poor, so rust spots usually appear. Need to remind friends that the NdFeB magnet should be placed in a place with good ventilation effect, rather than a place with large temperature difference.
In addition, the plating time is not enough, the poor plating of the magnet manufacturer is also one of the reasons, which is the problem of the process, in addition, if the NdFeB magnet seal is damaged, the strong magnet will also be oxidized, resulting in rust spots. Another important point is that before electroplating, the dirt on the surface of the NdFeB magnet can not be removed well, which is one of the reasons for rust spots.
Grounded NdFeB magnets will rust, the way to prevent rust is to avoid surface exposure to water and air, you can put it in water (alkaline better, can inhibit carbon dioxide), can also be immediately dried and sealed (best oil storage). After grinding, it is recommended to dry with an ultrasonic dryer immediately to reduce rust.
NdFeB magnets should avoid the following storage methods: in places where humidity is too high and air circulation is poor. When the temperature difference is very large, even if the salt spray test qualified products are stored in a harsh environment for a long time, rust spots may appear. If the surface is not coated, you can choose to use a desiccant or a vapor phase rust inhibitor and store it in a sealed package. Electroplated NdFeB magnets should not be placed in a place with high humidity for a long time, but should be placed in a cool and dry place.
