The researchment of cold rolling ability of the silicon steels

The study was carried to explain production of steel sheets, production of silicon steels, types of silicon steels, their properties and especially energy losses which occur during production, preventions for the reduction of these losses and the relationship between magnetic properties and thickness. This study was particularly explained to understand ıf cold rolling process could apply to these types of steel, the defects which occur during the cold rolling process and the effect of production condition to the material. The study composed of three parts. In the first part, general production process of these steels are discussed in general form also explained by the side of metallurgical aspects. After that the defects which occur by cold rolling process and the effects of these defects to the structure and microstructure was also reported. At the end of this part, cold and hot rolling processes are examined entirely. In the second part, the subjects of production methods of silicon steels which is an important group of electrical steels, types of these steels, chemical composition of these steels, magnetic properties of these steels and how these features can be changed was also defined. At the attendance of these part, the effects of production methods to the magnetic and mechanical properties of these steels, the process and function of surface treatments which are applied are clearly discussed. Also the threotical part completed by explaining the reasons which effect the losses in transformer cores, the relationship between magnetic properties and thickness, and efficiency factors which affect transformer cores and the preventions which to minimize these factors. The third part allocated to experimental studies. At the first stage of this part 6 pieces of scrap material which are completed their physical life are picked from junk collector. And the steels which have the same amount of silicon are bought from Assan Aluminyum firm. After metallografic treatments are applied to these steel sheets, microstructures of the steels are compared both with the orijinal ones and with the structures in the ASTM Handbook. At the second and main stage of this experimental study, M400 type silicon steel sheets are taken from the MGE Metal Company and the sheets are exposed to cold rolling process again in the same factory. The tensile strenght values of cold rolled and non-rolled M400 type silicon steel are also measured at the same factory. And then the group which are cold rolled are taken to the TUBITAK MAM scientific research center for core loss test. Following the core loss test, microstructures of the specimens of three different thickness are analysed. Also the chemical analyses of all specimens are appraised by defining the effects of microstructures. The study is concluded with the evalation of the results. Keywords: Electrical steel, core loss, cold rolling