Solidification process of grey cast iron largely determines the resultant carbon precipitates in form of graphite or carbides. Microstructure and hardness properties of grey iron were therefore studied. Aggregate scraps were melted with varying inoculants composition of 0.1 wt%, 0.2 wt% and 0.3 wt%. Cast produced was shaken out of the mould at various timing. Microstructures of the samples were determined and analyzed. Hardness properties were equally evaluated. It was observed that the occurrence of carbides was more with 0.25 hrs shakeout time than other varying timing. Increasing shakeout time was found to decrease hardness and increase the carbide grain size. When the ferrosilicon content increases, there is a gradual decrease in the hardness properties from 59.6 HRC to 53.2 HRC for 0.25 hrs shakeout time cast sample. Similar decreases were observed for various timing analyzed.
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