Oriented silicon steel has two kinds of hot rolling and cold rolling. The hot rolled silicon steel is replaced by cold rolled silicon steel sheet because of poor magnetic properties and large unit loss. The magnetic properties of cold-rolled oriented silicon steel sheets have obvious directionality. When magnetic lines of force pass along the rolling direction of the material, the magnetic permeability is the best, and the unit loss is the smallest. If the direction of the magnetic flux passes perpendicular to the direction of rolling, the guide is guided. The magnetic properties are significantly deteriorated. When the magnetic lines of force pass in the above two different directions, the unit loss varies greatly, and the latter is 3 to 4 times that of the former.
In the case of the same magnetic flux density and frequency, cold rolled oriented silicon steel has smaller unit loss and unit excitation capacity than hot rolled silicon steel; and its magnetic saturation point is higher, about 1.7T (17000Gs), while hot rolled silicon steel The magnetic saturation point is about 1.45T (14500Gs) or so.
Cold-rolled silicon steel is sensitive to mechanical processing. After punching, burring and tapping, its magnetic properties are particularly obvious. It is often necessary to be annealed to restore performance. After mechanical processing, the hot-rolled silicon steel sheet has little effect on its magnetic properties and does not require annealing.
In order to reduce the eddy current loss, it is necessary to apply an insulating varnish to the surface of the oriented silicon steel. For cold-rolled silicon steel, an insulating layer has been formed on the surface during the production process, generally no need to repaint, but for hot-rolled silicon steel, it needs to be coated with a layer of insulating varnish.https://www.chenglion.com/