Microstructural Characterization of Spheroidal Graphite Irons: A Study of the Effect of Preconditioning Treatment

The effect of preconditioning treatments on the control and improvement spheroidal graphite iron (SGI) microstructure was evaluated. In melt, 0.15% Zr-(Ca, Al) FeSi preconditioner added into different conditions. Four samples were produced for this investigation: (1) in first there no addition a comparative purposes; (2) second at cold charge; (3) third before last (4) fourth tapping from furnace. Microstructural characterization conducted to understand treatment SGI. Optical microscopy results show that increases graphite’s nodule density, ferrite content, nodularity. Scanning electron (SEM), energy dispersive (EDS), backscatter diffraction (EBSD) analysis used identify types microparticles present nodules. Some complex identified as AlMg2.5Si2.5N6, MgS, CaS. microstructural characteristics matrix, such grain size, crystallographic orientation, misorientation, also evaluated by EBSD. higher fraction, smaller hardness values. This work suggests practice has crucial knowledge is vital, allowing tailoring enhance mechanical properties SGI obtain best performance these materials.