To clarify the durability of inoculation in cast iron, the author carried out the experiment by the following method and founded on the results taken from the experiment, he made some considerations on the inoculation mechanism.
The molten iron having low eutectic degree is inoculated by ferro-silicon and calcium-silicide and after then, this is kept at a certain temperature for various of intervals. From the change of casting structure and the graphitization, procedure, the effect of inoculation in time elapse is studied.
The gists of the results are as follows :
1) The variation of the durability of inoculation effect in casting structure and tbat of graphitization phenomena in white pig iron in time elapse is shown almost similar tendency.
2) As the amount of inoculant increases, the durability of inoculation effect increases, but as higher the holding time of the melt, durability decreases.
3) Calcium silicide has shown better effect than ferro-silicon in the points of inoculation effect and of durability.
4) Partial concentration of graphitizing element contained in inoculant in the process of melting gives much important effect on the mechanism of inoculation than the effect of slight deoxdization of inoculant.