抄録
This investigation has been made to confirm how the structure of cast irons is influenced by oxides which construct refractory and clay. Synthetic Fe-C and Fe-C-Si cast irons have been melted in contact with the various oxides under oxidizing atmosphere, argon and carbon monoxide at 1 atm. pressure at 1300° and 1350°C.
The experimental results and the considerations for the results are as follows.
(1). In the case of the oxidizing atmosphere, the structure of synthetic Fe-C-Si cast irons becomes eutectic graphite or white cast iron structure. The structural changes are strongly controlled by oxidation of the oxidizing atmosphere.
(2). In the cases of argon and carbon monoxide, the original flake graphite structure becomes fine in the order SiO2, MgO, BaO or CaO. In the case of Al2O3, the original structure is retained and in the cases of BaO and CaO, the structure is most fine. And the orignal sulphur contents of the cast irons are also reduced in the similar order.
(3). In the case of argon atmosphere, it may be deduced from the thermodynamical consideration that the Fe-C-Si alloys are deoxidized in the following processes.
Si+2O+2MO (S) =M2SiO4
Si+2O+2MO (S) =M2SiO3
(4). In the case of CO atmosphere, it may be considered that the structural changes between flake graphite and fine eutectic graphite structure of Fe-C and Fe-C-Si alloys are due to the changes of sulphur contents of the alloys. In the case of argon atmosphere, it may be considered that the structural changes of Fe-C-Si alloys are due to deoxidation and desulphurization of the alloys.
