The dissolution behaviour of titanium in liquid steel under varying convection conditions and analysis of the reaction zone development between titanium and the solidified steel shell

摘要

In secondary metallurgy, alloying agents are added to liquid steel to obtain a specific steel grade. Initially a layer of steel solidifies around the cold addition and the time required for this shell to melt combined with the flow pattern in the ladle determines the location in the bath where the agent is released. Depending on the resulting local concentration, different inclusions may form. In the case of titanium additions a liquid reaction zone forms between the titanium and the solidified shell which influences the shell melting time. The microstructural reaction zone development has been described using a one-dimensional sharp interface model. Simulations were performed for different heat transfer coefficients at the solid iron - liquid iron interface to evaluate the influence of variable convection conditions throughout the ladle on the reaction zone composition and the required melting time. The results are qualitatively compared with experimental data.