Interfacial reactions during titanium dissolution in liquid iron: a combined experimental and modeling approach

The dissolution behavior of Ti in liquid Fe has been investigated experimentally and theoretically within the framework of inclusion formation in steel. In the experimental study, Ti cylinders have been immersed into liquid Fe and, subsequently, water-quenched. Macroscopic observation of quenched samples shows the initial solidification of an Fe shell around the Ti. Microstructural analysis of the Fe-Ti interfacial area with a scanning electron microscope equipped with an energy dispersive X-ray spectrometer reveals that a reaction zone develops in a three-step process: formation of a first liquid eutectic layer rich in Ti, formation of a second eutectic layer rich in Fe, and then mixing of both layers. The reaction zone grows in thickness up to 40 pct of the original sample radius and dissolves both parts of the Ti sample and the Fe shell. A simplified, one-dimensional, implicit finite volume model has been used to describe these phenomena theoretically. Good qualitative agreement is achieved between experiment and model. The model has been used to estimate the influence of original addition size, preheating, convection, and superheating on the required melt-back time.status: publishe