Silicon-Oxygen Equilibrium in δ-Iron at the Solid-Liquid Equilibrium Temperature

Abstract

Experiments on the solid-liquid equilibrium relationship in Fe-Si-O alloys were carried out using the zone melting technique.
The deoxidation constant with silicon in liquid iron was log K_Si (l) =-5.18 ([%Si (l)] <0.64) at the solid-liquid equilibrium temperature, which is in good agreement with the values given in the literature.
The silicon-oxygen equilibrium relationship in δ-iron at the solid-liquid equilibrium temperature is represented by the following equations:
log a_Si (s) ·a_O (s) ²=-7.19 ([%Si (s)] ≤0.5)
log f^Si_Si (s) =0.086 [%Si (s)]
log f^O_Si (s) =-15.9 [%O (s)]
log f^Si_O (s) =-9.05 [%Si (s)] +30 [%Si (s)] 2 ([%Si (s)] ≤0.1)
log f^O_O (s) ≈0