Precipitation of nitrides in non-oriented silicon steel

In the current work, the effect of rolling process in a plant and cooling rate during the solidification process under laboratory conditions on the formation of precipitation has been investigated. It has been found that a new homogenous nitride is formed by aluminium and magnesium. The formation of nitrides has been described according to a thermodynamic analysis and the values of Al/Mg mass ratio have ranged from 20 to 58 using a model based on data from automatic scanning electron microscopy. Further, MgO refractories have been identified as the main source of Mg for the formation of aluminium magnesium nitrides. In addition, cooling rate has a significant effect on the number density of nitrides. In order to decrease the number density and obtain a larger particle size, reducing cooling rate during solidification can promote a higher grain size and improve the magnetic properties of non-oriented silicon steels.