Assimilation and recovery characteristics of cored wire ferroalloy trimming additions for ladle and tundish metallurgy

In this study, the assimilation and recovery characteristics of several high melting range ferroalloys in liquid steel were investigated. An intelligent measurement system (IMS) consisting of a ;It could be demonstrated during melt trials in 65 kg of liquid steel that silicon-modified cored wire additions based on FeCr, FeMo, FeNb, FeV and FeW exhibit markedly superior solution characteristics compared to conventional unmodified cored wire additions. Since the modification results in an alteration of the mass transfer mechanism, higher and more consistent recovery rates for these high melting ferroalloys could be observed. The dramatic improvement in the time required for assimilation of modified cored-wires into a liquid bath renders these additions ideal for compositional trimming purposes in the tundish of a continuous caster, where residence time restrictions demand very rapid alloy assimilation periods.;In addition, a new technique was established for the determination of latent heat of fusion values for congruently melting materials. In this method, use was made of the recalescence phenomenon which accompanies the solidification of undercooled melts. The IMS was used to monitor the temperature increase of a levitated undercooled droplet upon solidification, which is due strictly to the release of the latent heat of crystallization. The liquid undercooled state was confirmed independently of temperature measurements by means of Fourier analysis of the signals from the surface of the droplet, a technique established previously at the University of Toronto. Following verification of the validity of this technique using well-established heat of fusion data, this temperature increase was measured in the so-called "hypercooled" region to yield heat of fusion data for the intermetallic compound FeSi.