What are the main differences between cold rolling and hot rolling of silicon steel sheets in transformer cores?
Because the magnetic conductivity of cold-rolled silicon steel with high and low loss, so to make the transformer has the advantages of small size, light weight, the advantages of high efficiency, the performance of hot-rolled silicon steel strip is slightly inferior to cold-rolled silicon steel.
Cold rolling is usually done without heating before rolling. However, the strip shape is easy to occur because of the small strip thickness. Moreover, after cold rolling is finished products, many complicated processes are adopted to control the dimensional accuracy and surface quality of strip steel. Cold rolling production line length, equipment, complex process. With the improvement of strip size accuracy, flatness and surface quality requirements, the control model, L1 and L2 system, and shape control method of cold rolling mill are much more hot than that of cold rolling mill. Moreover, the temperature of roll and strip is also one of the most important control indexes.
Hot rolling, as the name suggests, is of high temperature and therefore has little deformation resistance and can achieve large deformation. Taking the steel plate rolling as an example, the thickness of the continuous casting slab is about 230mm, and the final thickness is 1~20mm after rough rolling and finishing rolling. At the same time, because of the small width to thickness ratio and low requirement of dimension accuracy, it is difficult to control the crown shape. As for the requirements of the organization, it is generally realized by controlling rolling and controlling cooling, that is to say, to control the rolling temperature, the final rolling temperature and the coiling temperature of the finishing mill to control the microstructure and mechanical properties of the strip.
