Behavior of Si in the Deoxidation of Molten Iron with Al-Si Alloys

Abstract

The deoxidation process of Al-Si alloys, which was consisted of 5 stages, was obtained through the experimental results in stirring and quasistatic liquid iron. The behavior of Si at the addition period of deoxidizer, formation period of Al₂O₃ inclusion, and reoxidation period was especially important.
So these complex deoxidation effects were investigated by further experiments.
The experimental results are summarized as follows.
(1) At the addition period of deoxidizer, the dispersion and transfer of Al-Si alloy into molten iron is better than that of Al or Si deoxidizer. This is due to the effect of Si in the deoxidizer and its first stage behavior is the same as that of Ca-Si alloy.
(2) The formation of Al₂O₃ cluster is retarded considerably when Si is remained in molten iron as soluble Si. This behavior is discussed through the measurement of the interfacial energy between molten iron and Al₂O₃ inclusion.
(3) On the reoxidation period, the total oxygen content is kept low for a long time while soluble Si is remained in molten iron.