Influence of Alloying Elements on the Thermodynamic Properties of Titanium in Molten Steel

Abstract

The influences of alloying elements of chromium, nickel, manganese, molybdenum, copper, and oxygen on the thermodynamic property of titanium in molten iron were investigated at 1873 K to improve control of the formation of titanium compounds in the steelmaking processes. At a certain titanium potential controlled by the coexistence of Ti₃O₅ and Ti₂O₃ with steel, the interaction parameters between alloying elements and titanium in molten iron were determined as follows.

$$ \varepsilon ^{{{\text{Mn}}}}_{{{\text{Ti}}}} = - 27.4( \pm 0.66),\quad \varepsilon ^{{{\text{Cr}}}}_{{{\text{Ti}}}} = 5.33( \pm 0.84),\quad \varepsilon ^{{{\text{Ni}}}}_{{{\text{Ti}}}} = - 3.93( \pm 0.51),\quad \varepsilon ^{{{\text{Mo}}}}_{{{\text{Ti}}}} = 5.76( \pm 0.69),\quad \varepsilon ^{{{\text{Cu}}}}_{{{\text{Ti}}}} = 3.44( \pm 0.69) $$

Through the investigation of titanium deoxidation equilibria in molten iron, the activity coefficient of titanium and the first-order interaction parameter between oxygen and titanium were determined as follows:

$$ \gamma _{{{\text{Ti}}}}^{ \circ} = 0.0215(\pm0.00062),\quad \varepsilon ^{{{\text{Ti}}}}_{{\text{O}}} = - 160(\pm10) $$

Also, titanium deoxidation of molten 304 stainless steel was measured and compared with the calculated results using the determined interaction parameters.