Is silicon steel sheet a magnetic material?
Silicon steel is a silicon iron alloy with silicon content of about 3%. Silicon steel sheets are widely used in medium and low frequency transformers and motor cores. Silicon steel is characterized by its highest saturation magnetic flux density (2.0T or more) in common soft magnetic material, so it can work at very high working points as a transformer core (for example, working magnetic induction 1.5T). However, silicon steel in soft magnetic materials commonly used in iron loss is the largest, in order to prevent the core caused loss is too large, its use frequency is not high, the general can only work under 20KHz, mainly used in power transformer.
In order to obtain better magnetic properties, later people invented cold rolled silicon steel sheet, that is, rolling at low temperature and annealing. Cold rolled oriented silicon steel sheet is one of the representatives. Cold rolled oriented silicon steel firstly cold rolled the slab, resulting in a lot of structural defects in the material. In the annealing process, the material changes on the structure (called recrystallization), this change will make the silicon steel sheet in a direction of magnetic properties is very good, that is to say on the magnetic properties and direction, so it is called grain oriented silicon steel. In the final use, the magnetic lines of force in the core are passed along the best magnetic properties so that the magnetic potential of silicon steel sheets can be maximally exploited. For example, in the transformer, the magnetic core material is passed along one direction, if the silicon steel sheet tailoring, and then wound into the core, the core is the circumference direction is just the best direction of magnetic properties of silicon steel sheet, so will the high permeability core, easy magnetization, low energy loss, and ultimately improve the transformer efficiency.
Silicon steel is usually thin, in order to minimize eddy current losses in the core of the transformer. At present, silicon steel sheet is mainly divided into two categories: hot rolling and cold rolling. A hot rolled silicon steel is rolled by rolling the silicon steel sheet over 850 degrees Celsius before annealing. Because the rolling temperature is high, the rolled silicon steel sheets are isotropic, that is to say, the magnetic properties of silicon steel sheets are the same in all directions. This kind of isotropic silicon steel is also called non oriented silicon steel. Non oriented silicon steel is widely used in motor stator or rotor. Because the motor stator and rotor are to be manufactured, a round piece must be punched on the large silicon steel sheet. At this time, the silicon steel sheet is always expected to be magnetic in the circumferential direction, so the non oriented silicon steel should be used.
