Under normal circumstances, the surface of the magnet has an electroplated layer (of course, it is also required that the neodymium iron boron magnet is not electroplated, and some concentrated magnets do not need electroplating, and the appearance is similar to ferrite), and it does not rust. Rust spots are produced because it is in a relatively high humidity environment and the air circulation in the working environment is very poor, so rust spots usually appear. I need to remind my friends that the NdFeB magnets should be placed in a place with good ventilation, not a place with large temperature changes.
In addition, insufficient electroplating time and poor electroplating of magnet manufacturers are also one of the reasons. This is a problem with the process flow. In addition, if the seal of the neodymium iron boron magnet is damaged, the strong magnet will also be oxidized, causing rust spots. Another important point is that before electroplating, the dirt on the surface of the NdFeB magnet cannot be removed well, which is also one of the reasons for the rust spots.
How to avoid：
The grounded neodymium iron boron magnet will rust. The way to prevent rust is to avoid exposing the surface to water and air. You can put it in water (the alkalinity is better and it can inhibit carbon dioxide), or it can be dried and sealed immediately (the best oil storage). After grinding, it is recommended to use an ultrasonic dryer to dry it immediately to reduce rust.
The following storage methods should be avoided for NdFeB magnets: In places with excessive humidity and poor air circulation. When the temperature difference changes greatly, even if the products that have passed the salt spray test are stored in a harsh environment for a long time, rust spots may appear. If there is no coating on the surface, you can choose to use a desiccant or a vapor phase rust inhibitor and store it in a sealed package. Electroplated neodymium iron boron 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.
