The scope of the current work is to quantify eventual effects of preconditioner choice on microstructure, mechanical properties and casting performance in gray cast iron melts produced under carefully controlled laboratory conditions. the experimental approach involves preconditioning of gray iron melts, produced according to the same charging/time and temperature/time program, with either high purity ferrosilicon (HP-FeSi), standard ferrosilicon (Std. FeSi), abrasive grade silicon carbide (Abr. SiC) or metallurgical grade silicon carbide (Met. SiC) as the preconditioning agent. In general there are only minor differences in microstructural features and mechanical properties in the experimental irons produced using the four different preconditioning agents. The carbon and silicon yield was found to be lowest for the irons produced with the abrasive grade SiC and highest for the irons produced using standard grade FeSi. The amount of graphite in thick section size specimens was found to be highest in the irons produced with metallurgical grade SiC and lowest in the irons produced with standard FeSi. In thin section specimens the amount of graphite was highest in the irons produced with FeSi and lowest in the irons produced with SiC. All examined thick plate specimens had type A graphite, size 3, with some minor type D graphite areas. The graphite was also mainly type A, size 4, in the thin plate specimens, small areas of type B and type D graphite were also present. The eutectic cell number is slightly higher in the irons produced with SiC than in those produced with FeSi.
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