Abstract
This investigation was carried out to examine the influence of heating condition, pretreatment and com-position of material on the incubation period appearing in induction heating of Fe-Graphite compact.
The results were summarized as follows:
1) The incubation period increases with decreasing frequency of induced current and density of the compact. It also increases with increasing graphite content.
2) The addition of copper and preheating-cooling of the compact before induction heating reduce the incubation period.
3) The induction heating up to 900°C reduces extremely the incubation period in re-heating of the compact after cooling.
4) The possible explanation for the existence of the incubation period is that the compact may be not heated effectively since the high frequency current will penetrate deeply into the compact, because of its high electric resistance.
However, when the electric resistance is decreased by the evolution of absorbed gases and also by the neck-growth in the compact, an effective rapid heating becomes possible.
