Influência da quantidade e morfologia de faialita e sílica nas características de um aço elétrico de grão orientado

Abstract

Oriented-Grain (GO) electrical steels are materials which show excellent magnetic properties on the rolling direction. These steels have been developed to achieve low core loss and high magnetic permeability, required for higher equipment performance with increased energy saving, such as power transformers. During the decarburization step production the strop carbon content is reduced and occurs formation of fayalite and silica on its inner surface. Afterwards, during the box annealing, these oxides react with the magnesia forming forsterite. The functions of this later compound are to insolate electrically the steel surface and to apply tensile stress on the strip. In this work, it has been developed a methodology to quantify, by means of Fourier transformed infrared spectroscopy, the fayalite and silica formed during the decarburization. Moreover, it has been evaluated the influence of decarburization conditions in the oxides concentration formed during this treatment. Finally, it has been verified the influence of the fayalite and silica concentrations on the glass film morphology and on the steel magnetic properties