Influence of SiC and FeSi addition on the characteristics of gray cast iron melts poured at different temperatures

The influence of silicon carbide and ferrosilicon as silicon carriers on the cooling curve characteristics, fluidity, microstructure, chill depth and hardness of hypoeutectic gray cast irons poured at different temperatures has been investigated. It has been found that the addition of SiC instead of FeSi as a silicon carrier resulted in variations in the thermal analysis characteristics and microstructure together with increasing fluidity as well as decreasing chill depth for the whole range of pouring temperatures explored. Microstructural studies revealed that SiC addition resulted in the maximum amount of A-typed graphite with a more uniform distribution. The finest microstructure (i.e. refined eutectic cells) was also obtained with SiC addition. These observations were attributed to the pre-inoculation behavior of SiC in gray cast iron with a slow fading tendency within the melt during solidification.