The hysteresis effect of magnetic steel magnets refers to the characteristic of hysteresis in the relationship between magnetic field intensity and magnetic induction intensity. Simply put, when a steel magnet is magnetized under the action of an external magnetic field, the change in its magnetic induction intensity B will lag behind the change in magnetic field intensity H. This effect is caused by the magnetic domain structure and magnetic domain wall movement inside the magnetic steel magnet.
Specifically, the magnetic moments of atoms or molecules inside the magnet tend to be aligned in the same direction under the action of a magnetic field, forming a macroscopic magnetic moment. When the external magnetic field changes, the direction of the magnetic moment will change accordingly, but due to the resistance of the magnetic domain structure and magnetic domain walls, the change in magnetic induction intensity B will lag behind the change in magnetic field intensity H. This hysteresis phenomenon is the hysteresis effect.
The size of the hysteresis effect is usually measured by parameters such as coercivity, remanence and saturation magnetic induction. Coercive force is the minimum external magnetic field intensity required to completely demagnetize a steel magnet; remanence refers to the magnetic induction intensity retained by the steel magnet after the external magnetic field disappears; saturation magnetic induction intensity refers to the magnetic induction intensity of the steel magnet at a certain temperature. The magnetic field strength when the magnetic induction intensity reaches its maximum value.
In practical applications, the size and nature of the hysteresis effect have a great impact on the performance and application of magnetic steel magnets. For example, in electrical equipment such as motors, generators, and transformers, magnetic steel magnets with large coercive force and residual magnetism are needed to maintain high magnetic field strength and stability. In electronic equipment such as audio and video, magnetic steel magnets with smaller coercive force and residual magnetism are needed to obtain better sound quality and picture effects.
In short, understanding and mastering the hysteresis effect of magnetic steel magnets is of great significance for their application and performance optimization. In practical applications, it is necessary to select magnetic steel magnets with appropriate coercivity and remanence according to specific needs in order to obtain the best application results.
