Microstructural Study of as-cast Fe-Si Alloys. Effect of Percentage of Silicon

Silicon steels are materials used in construction of electric motors and transformers. Silicon is an effective element to improve the electrical and magnetic properties. During the solidification stage is defined the distribution of solute on the solid as segregation or coring. This paper researched the effect of the percentage of silicon on the microstructure and segregation profiles of the Fe-0.5wt%Si, Fe-1.5wt%Si and Fe-3wt%Si cast alloys. The samples were metallographically prepared by conventional techniques. The concentration of silicon in grain boundary regions was carried out by scanning electron microscopy (SEM) with EDS-WDS microanalysis, the morphological changes of the grain as a function of silicon was evaluated by optical microscopy. Experimental microsegregation patterns showed significant difference from the Scheil model and greater agreement with this model when considering convective-diffusive conditions. The microstructural study revealed discrepancies with the solidification pattern governed by the solidification interval.